Aegilops

Benjamin Kilian; Kerstin Mammen; Eitan Millet; Rajiv Sharma; Andreas Graner; Francesco Salamini; Karl Hammer; Hakan Özkan

Gene flow between domesticated species and their wild relatives is receiving growing attention. This study addressed introgression between wheat and natural populations of its wild relatives (Aegilops species). The sampling included 472 individuals, collected from 32 Mediterranean populations of three widespread Aegilops species (Aegilops geniculata, Ae. neglecta and Ae. triuncialis) and compared wheat field borders to areas isolated from agriculture. Individuals were characterized with amplified fragment length polymorphism fingerprinting, analysed through two computational approaches (i.e. Bayesian estimations of admixture and fuzzy clustering), and sequences marking wheat-specific insertions of transposable elements. With this combined approach, we detected substantial gene flow between wheat and Aegilops species. Specifically, Ae. neglecta and Ae. triuncialis showed significantly more admixed individuals close to wheat fields than in locations isolated from agriculture. In contrast, little evidence of gene flow was found in Ae. geniculata. Our results indicated that reproductive barriers have been regularly bypassed during the long history of sympatry between wheat and Aegilops.

Studying of genetic relationships among Triticum L. and Aegilops L. species is very important for broadening the cultivated wheat genepool, for monitoring genetic erosion and for breeding reasons, because the genus Aegilops represents the largest part of the secondary gene pool of wheat, includes the wild relatives of cultivated wheat which contain numerous unique alleles that are absent in modern wheat cultivars and it can contribute to broaden the genetic base of wheat and improve yield, quality and resistance to biotic and abiotic stresses of wheat. Molecular markers have proved valuable in crop breeding. Selection of the best marker system depends on aim of research and ploid level of studied being.

Chapter 1 Aegilops Benjamin Kilian, Kerstin Mammen, Eitan Millet, Rajiv Sharma, Andreas Graner, Francesco Salamini, Karl Hammer, and Hakan Özkan 1.1 Introduction The genus Aegilops L. belongs to the tribe Triticeae within the Pooideae subfamily of the grass family Poaceae. The tribe includes six major genera (http:// www.k-state.edu./wgrc/Taxonomy/Triticeaetax.html ), among which the important crop genera are Triticum (wheat), Hordeum (barley), and Secale (rye). The phylogenetic relationships and evolution within the Triticeae are of great interest due to potentially favorable alleles to be discovered in wild wheat relatives and to be transferred to bread wheat. However, especially the relationships within and between Aegilops and Triticum in the subtribe Triticinae are a matter of ongoing discussion, and the relationships among the taxa are far from being completely understood. This is also documented in various classification systems, as presented for Aegilops in Table 1.1. Most researchers currently follow the latest monograph of van Slageren (1994). However, new data B. Kilian (*) Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Genebank/Genome Diversity, Gatersleben, Germany e-mail: kilian@ipk-gatersleben.de “For the sake of future generations, we MUST collect and study wild and weedy relatives of our cultivated plants as well as the domesticated races. These sources of germplasm have been dangerously neglected in the past, but the future may not be so tolerant. In the plant breeding programs of tomorrow we cannot afford to ignore any source of useable genes.” Harlan (1970) have been recently produced and some aspects have to be reconsidered. New molecular data are urgently needed to provide more insights in the Triticeae phylogeny. Tables 1.1 and 1.2 report the Aegilops taxa considered in this chapter. The genus Aegilops comprises 23 annual species, of which 11 are diploids and 12 are allopolyploids (see Table 1.2 and the species descriptions for synonyms). Some Aegilops species participated in wheat evolution and played a major role in wheat domestication. Thus, the genus Aegilops represents the largest part of the secondary gene pool of wheat, and several species have been used in crop improvement programs. The latest revision of Aegilops by van Slageren (1994) is based on morphological studies. Van Slageren conducted field trips in the years 1988–1994 and examined about 20,000 herbarium specimens representing, in van Slageren’s opinion, an estimated 75–85% of all Aegilops material available. In this chapter, we therefore refer to van Slageren (1994) and Hammer (1980a, b) for morphological descriptions and history of the genera Aegilops and nomenclature. For wheat, the latest comprehensive, systematic overview was completed in 1979 by Dorofeev and colleagues. In this chapter, the nomenclature and the genome formula given for Triticum by Dorofeev et al. (1979) is mainly followed (exception e.g., T. dicoccon Schrank). Other concise comparisons of the main wheat classifications are also available (Hanelt 2001; Mac Key 2005; Hammer et al. 2011). This chapter is an introduction and an overview on Aegilops. A key and a brief botanical description are presented, together with ear morphology and distribution maps, and cytological and molecular data for each species. C. Kole (ed.), Wild Crop Relatives: Genomic and Breeding Resources, Cereals, DOI 10.1007/978-3-642-14228-4_1, # Springer-Verlag Berlin Heidelberg 2011 1 1 Ae. biuncialis Vis. Ae. biuncialis Vis. 2 Ae. columnaris Zhuk. Ae. columnaris Zhuk. 3 Ae. geniculata Roth Ae. geniculata Roth 4 ssp. geniculata ssp. gibberosa (Zhuk.) Hammer Ae. kotschyi Boiss. Ae. kotschyi Boiss. 5 6 Ae. neglecta Req. ex Bertol. ssp. neglecta (4x) ssp. recta (Zhuk.) Hammer (6x) Ae. peregrina (Hackel) Maire et Weiller ssp. peregrina 7 Ae. triuncialis L. 8 ssp. triuncialis ssp. persica (Boiss.) Zhuk. Ae. umbellulata Zhuk. ssp. umbellulata ssp. transcaucasia Dorof. et Migusch. Triticum kotschyi (Boiss.) Bowden Ae. neglecta Req. ex Triticum triaristatum (Willd.) Godr. et Bertol. (4x and Gren. (4x and 6x) 6x) Ae. peregrina (Hack. Triticum kotschyi in J.Fraser) (Boiss) Bowden Maire et Weiller Ae. kotschyi Boiss. Ae. triaristata Willd. (4x and 6x) Ae. peregrina (Hackel) Maire et Weiller var. peregrina var. brachyathera (Boiss.) Maire et Weiller Ae. triuncialis L. Triticum triunciale (L.) Ae. triuncialis L. Raspail var. triuncialis var. persica (Boiss.) Eig Triticum umbellulatum Ae. umbellulata Ae. umbellulata Zhuk. (Zhuk.) Bowden Zhuk. Ae. umbellulata Zhuk. Hammer (1980a, b) Kihara (1954) Eig (1929) Zhukovsky (1928) Ae. lorentii Hochst. Ae. biuncialis Vis. Ae. biuncialis Vis. Ae. biuncialis Vis. Ae. columnaris Zhuk. Ae. columnaris Ae. columnaris Ae. columnaris Zhuk. Zhuk. Zhuk. Ae. geniculata Roth Ae. ovata L. Ae. ovata L. Ae. ovata L. Ae. kotschyi Boiss. Ae. kotschyi Boiss. Ae. triaristata Willd. (4x and 6x) Ae. kotschyi Boiss. Ae. triaristata Willd. (4x and 6x) Ae. triaristata Willd. (4x and 6x) ssp. neglecta (4x) ssp. recta (Zhuk.) Hammer (6x) Ae. peregrina (Hackel) Ae. variabilis Maire et Weiller Eig Ae. variabilis Eig Ae. neglecta Req. ex Bertol. ssp. peregrina ssp. cylindrostachys (Eig et Feinbrun) Maire et Weiller Ae. triuncialis L. Ae. triuncialis L. ssp. triuncialis ssp. persica (Boiss.) Zhuk. Ae. umbellulata Zhuk. Ae. Ae. triuncialis L. Ae. triuncialis L. umbellulata Zhuk. B. Kilian et al. Ae. umbellulata Zhuk. Triticum macrochaetum Ae. lorentii Hochst. (Shuttl. et Huet) Richter Ae. columnaris Triticum columnare Zhuk. (Zhuk.) Morris et Sears Triticum ovatum (L.) Ae. ovata L. Raspail 2 Table 1.1 Overview of selected Aegilops classifications This chapter van Slageren (1994) Kimber et Sears (1983) Whitcombe (1983) Section Aegilops ssp. transcaucasia Dorof. et Migusch. (continued) van Slageren (1994) Kimber et Sears (1983) Whitcombe (1983) Section Comopyrum 9 Ae. comosa Sibth. et Sm. Ae. comosa Sm. in Sibth. et Sm. Triticum comosum (Sibth. et Sm.) Richter Hammer (1980a, b) Ae. comosa Ae. comosa Sibth. et Sibth. et Sm. Sm. ssp. comosa var. comosa ssp. heldreichii (Boiss.) var. subventricosa Boiss. Eig (syn.: var. subventricosa Boiss.) Kihara (1954) Eig (1929) Zhukovsky (1928) Ae. comosa Sibth. et Sm. Ae. comosa Sibth. et Sm. Ae. comosa Sibth. et Sm. ssp. comosa ssp. heldreichii (Boiss.) Eig ssp. heldreichii (Holzm.) Eig 10 Ae. uniaristata Vis. Ae. uniaristata Vis. Triticum uniaristatum (Vis.) Richter Ae. uniaristata Vis. Ae. uniaristata Vis. Ae. uniaristata Ae. uniaristata Ae. uniaristata Vis. Vis. Vis. Section Cylindropyrum 11 Ae. cylindrica Host Ae. cylindrica Host Triticum cylindricum Ces. Triticum dichasians (Zhuk.) Bowden Ae. cylindrica Host Ae. caudata L. Ae. cylindrica Host Ae. cylindrica Ae. cylindrica Ae. cylindrica Host Host Host Ae. caudata L. Ae. caudata L. Ae. caudata L. 12 Ae. markgrafii (Greuter) Hammer Section Sitopsis 13 Ae. bicornis (Forssk.) Jaub. et Sp. Ae. caudata L. Ae. bicornis Triticum bicorne (Forssk.) Jaub. et Forssk. Spach var. bicornis var. anathera Eig 14 Ae. longissima Schweinf. Ae. longissima et Muschl. Schweinf. et Muschl. 15 Ae. sharonensis Eig Ae. sharonensis Eig 16 Ae. searsii Feldman et Kislev ex Hammer Ae. searsii Feldman et Kislev ex Hammer Ae. speltoides Tausch 17 Ae. speltoides Tausch ssp. speltoides ssp. ligustica (Savign.) Zhuk. var. speltoides var. ligustica (Savign.) Fiori Triticum longissimum (Schweinf. et Muschl.) Bowden Ae. markgrafii (Greuter) Hammer Ae. bicornis (Forssk.) Jaub. et Spach Ae. bicornis (Forssk.) Jaub. et Spach Ae. longissima Schweinf. et Muschl. Ae. longissima Ae. longissima Ae. longissima Ae. longissima Schweinf. et Schweinf. Schweinf. (Schweinf. et Muschl. emend. et Muschl. et Muschl. Muschl.) Eig Eig s.l. ssp. longissima ssp. sharonensis (Eig) Ae. sharonensis Hammer Eig Ae. searsii Feldman et Kislev ex Hammer Ae. sharonensis Eig Triticum searsii Ae. searsii (Feldman et Kislev) Feldman et Feldman Kislev Ae. speltoides Triticum speltoides Tausch (Tausch) Gren. ex Richter Ae. ligustica (Savign.) Coss. Ae. speltoides Tausch ssp. speltoides ssp. ligustica (Savign.) Zhuk. 1 Aegilops Table 1.1 (continued) This chapter Ae. bicornis (Forssk.) Jaub. et Spach Ae. speltoides Tausch Ae. bicornis (Forssk.) Jaub. et Spach Ae. speltoides Tausch Ae. bicornis (Forssk.) Jaub. et Spach Ae. speltoides Tausch Ae. ligustica (Savign.) Coss. 3 (continued) 4 Table 1.1 (continued) This chapter van Slageren (1994) Kimber et Sears (1983) Whitcombe (1983) Section Vertebrata 18 Ae. crassa Boiss. (4x and Ae. crassa Boiss. (4x Triticum crassum 6x) and 6x) (Boiss.) Aitch. et Hemsl. (4x and 6x) 19 Ae. vavilovii (Zhuk.) Chennav. (6x) Ae. vavilovii (Zhuk.) Triticum syriacum Chennav. Bowden 20 Ae. juvenalis (Thell.) Eig Ae. juvenalis (Thell.) Triticum juvenale Eig Thell. 21 Ae. tauschii Coss. ssp. tauschii ssp. strangulata (Eig) Tzvel. 22 Ae. ventricosa Tausch Subgenus Ambylopyrum 23 Ae. mutica Boiss. ssp. mutica ssp. loliacea (Jaub et Spach) Zhuk. Ae. tauschii Coss. Triticum tauschii (Coss.) Schmalh. Ae. ventricosa Ces. Triticum ventricosum Tausch Triticum tripsacoides Ambylopyrum (Jaub. et Spach) muticum (Boiss.) Eig Bowden var. muticum var. loliaceum (Jaub. et Spach) Eig Hammer (1980a, b) Ae. crassa Boiss. Ae. crassa Boiss. (4x (4x and 6x) and 6x) Ae. vavilovii (Zhuk.) Chennav. Ae. juvenalis (Thell.) Eig Kihara (1954) Eig (1929) Zhukovsky (1928) Ae. crassa Boiss. (4x and 6x) Ae. crassa Boiss. (4x and 6x) Ae. crassa Boiss. (4x and 6x) ssp. crassa ssp. vavilovii Zhuk. (6x) Ae. juvenalis (Thell.) Eig Ae. turcomanica Roshev. Ae. squarrosa L. Ae. tauschii Coss. Ae. juvenalis Ae. juvenalis Ae. turcomanica (Thell.) Eig (Thell.) Eig Roshev. Ae. squarrosa L. Ae. squarrosa L. Ae. squarrosa L. Ae. ventricosa Tausch Ae. ventricosa Tausch Ae. ventricosa Tausch Ae. ventricosa Tausch Ae. ventricosa Tausch Ae. mutica Boiss. Ae. mutica Boiss. Ae. mutica Boiss. Ae. mutica Boiss. Ae. mutica Boiss. var. muticum var. loliacea (Jaub. et Spach) Eig B. Kilian et al. 1 Aegilops Table 1.2 Sections and species of Aegilops. Genomic formulas of tetraploids and hexaploids are cited as “female male parent.” Underlining indicates modification of the same genome as present in the diploid species. Genome (G) and cytoplasm (C) symbols are according to Kimber and Tsunewaki (1988). Mean nuclear DNA content (Mean 1C) in pg of Aegilops species according to Eilam et al. (2007, 2008). nd – not determined Aegilops section Diploid Tetraploid Hexaploid Species G C Mean 1C Species G C Mean 1C Species G C Mean 1C Aegilops L. Ae. umbellulata U U 5.38 Ae. biuncialis UM U 10.37 Ae. columnaris UM U2 10.86 Ae. geniculata MU Mo 10.29 SU S2 12.64 Ae. kotschyi Ae. neglecta ssp. neglecta UM U 10.64 Ae. neglecta ssp. recta UMN U 16.22 Ae. peregrina SU Ss 12.52 Ae. triuncialis UC, C,U 9.93 CU Comopyrum (Jaub. et Spach) Zhuk. Ae. comosa M M 5.53 Ae. uniaristata N N 5.82 Cylindropyron (Jaub. et Spach) Zhuk. Ae. markgrafii C C 4.84 Ae. cylindrica DC D 9.59 Sitopsis (Jaub. et Spach) Zhuk Ae. bicornis Sb Sb 6.84 Ae. longissima Sl Sl 7.48 Ae. sharonensis Ssh Sl 7.52 Ae. searsii Ss Ss 6.65 Ae. speltoides S S 5.81 Vertebrata Zhuk. emend. Kihara Ae. tauschii D D 5.17 Ae. crassa ssp. crassa (4x) DM D2 10.86 Ae. crassa ssp. crassa (6x) DDM D2 nd DMS D2 17.13 Ae. vavilovii DMU D2 nd Ae. ventricosa DN D 10.64 Ae. juvenalis Subgenus Amblyopyrum Ae. mutica T nd nd 5 6 1.2 Botany of the Genus Aegilops 1.2.1 Geographical Distribution and Ecology of Aegilops Aegilops is a Mediterranean–western Asiatic element comprising species that occur in both the Mediterranean and Irano-Turanian regions (Hedge et al. 2002). The genus occurs from 10 West to 82 East and from 24 to 47 North (introductions outside the natural distribution are not considered). Aegilops grow in Mediterranean Europe and southern Ukraine, the Crimea; as well as Cis- and Transcaucasia; in Africa, north of the Sahara; in western and Central Asia, the region bordered by the deserts of the Arabian peninsula in the south and by the Tian Shan mountains in the east. Several Aegilops species have been introduced in the US, of which Ae. cylindrica is now widespread. Several species are adventive in northern and northwestern Europe and in the Canary Islands. The altitudinal distribution of the genus varies from 400 m up to 2,700 m, but it differs greatly among the species (Hodgkin et al. 1992; van Slageren 1994). Geographical information system (GIS) distribution maps of Aegilops species developed for this chapter are based on van Slageren’s (1994) and on our own observations. Adventive locations outside the natural species distribution range are not considered. According to van Slageren (1994), the largest diversity of the genus Aegilops can be found in the Fertile Crescent ranging from Palestine/Israel – Lebanon – Syria – Southeast Turkey – North Iraq to Northwest Iran. Within this area, the central part of the Fertile Crescent between Euphrates and Tigris, where the southern slopes of the Taurus mountain range meet the lowlands and steppes, has the largest diversity. Mapping of Aegilops species richness identifies Northwest Jordan, Israel, Lebanon, western Syria, Iraq, and Turkey as areas with more than nine Aegilops species. Two main hotspots were found with 12–14 Aegilops species (1) western Syria – Northeast Lebanon and (2) northern Iraq (van Slageren 1994; Maxted et al. 2008). According to Hammer (1980a), the origin of Aegilops can be sought in the Transcaucasian area, from which diploid species migrated in western and southwestern directions. Later, groups of tetraploid species due to their adaptation capacity spread again both west and southwest around the Mediterranean basin, as well as east into Central Asia. B. Kilian et al. Aegilops show adaptation to disturbed environments, such as pastures, roadsides, garrigue, and maquis, various types of park-forest, and in edges of and within cultivation, thus both in ruderal and segetal environments. Aegilops species grow intermingled with other grasses (including other Aegilops and Triticum species) and with shrubs. They rarely dominate the vegetation. Ecological descriptions in this chapter are based on van Slageren (1994). The annual growth habit of Aegilops and the predominance of self-pollination are advantageous life strategies in a region with seasonal rainfall and hot summer. Several Aegilops species are nevertheless (partially) outcrossing: Ae. mutica and Ae. speltoides (Hammer 1980a; Sakamoto 1982). Aegilops shows morphological diversification of the spike and variation in seed dispersal. Three types of spike disarticulation are recognized: wedge, barrel, and whole-spike. Cultivated or otherwise improved forms of Aegilops species do not exist (van Slageren 1994). 1.2.2 Description of the Genus Aegilops Family: Poaceae Barnhart, Bull. Torrey Bot. Club 22:7 (1895), nom. cons. – Alternative name: Gramineae Juss., Gen. pl. 28 (1789), nom. cons. – Type genus: Poa L. Subfamily: Pooideae. Autonym; used for the first time by A.C.H. Braun in Ascherson, Fl. Brandenburg 1(2):810 (1864, “Poeideae R. Br.”) Tribe: Triticeae Dumort., Observ. Gramin. belg. 84 (1824) – Type genus: Triticum Subtribe: Triticinae Griseb., Spic. fl. rumel. 2 (5/ 6):422 (1846). The conspectus of Aegilops follows Hammer (1980b) with some additions/corrections mainly from Hammer (1987) and van Slageren (1994). For the description of species, the following main sources have been consulted: Hammer (1980b), van Slageren (1994), the classical work on Aegilops of Zhukovsky (1928), and Eig (1929). Specific information has been obtained from Bor (1968), Tutin and Humphries (1980), and Davis (1985). For vernacular names, uses, etymology, etc., see van Slageren (1994). An index to scientific names used is presented at the end of the chapter (see Table in Appendix). 1 Aegilops 1.2.2.1 Aegilops L. Typus: Aegilops triuncialis L. designated by Hammer (1980a), sustained by Jarvis (1992), see also van Slageren (1994). Aegilops can be distinguished from Triticum by the absence of a well-developed keel on the glumes, which causes the sharp angle in the glume outline of both the wild and cultivated Triticum taxa (van Slageren 1994). A key to the wild taxa of Aegilops and Triticum can be found in van Slageren (1994). The genus Aegilops has been divided into five sections (Zhukovsky 1928; van Slageren 1994). Three of the sections, namely Aegilops (species with U-genome and combinations of other genomes with U), Cylindropyrum (C- and DC- genomes), and Vertebrata (D-genome and combinations of other genomes with D) consist of both diploid and polyploid species, and the two other sections Comopyrum (M- or N-genomes) and Sitopsis (S-genome) have only diploid members (Table 1.2). The key to the sections of Aegilops can be found in van Slageren (1994). Genome: x ¼ n ¼ 7. The genus Aegilops consists of 11 diploid (2n ¼ 14) and 12 polyploid species (tetraploid: 2n ¼ 28; hexaploid 2n ¼ 42). Ae. crassa and Ae. neglecta have both tetraploid and hexaploid races (Table 1.2). For genome formula, cytoplasm, and genome size, see Table 1.2. 1.2.3 Determination and Species Key of the Genus Aegilops The key of Hammer (1982) allows determining species and few of the infraspecific taxa (see also Hammer 1980b; Table 1.3). Originally, the former key was published in German (Hammer 1980b), followed by an English version (Hammer 1982). A modern key is provided by van Slageren (1994), which contains only few infraspecific races. We include Aegilops mutica in the genus Aegilops (Tables 1.1 and 1.2). Nielsen (1981) found that the length of the rachis internode of the lowest fertile spikelet is a good additional character for the distinction of some difficult species, e.g., Ae. triuncialis and Ae. kotschyi or Ae. geniculata and Ae. umbellulata. He reported the following data: Ae. biuncialis: 2–5 mm; Ae. columnaris: 1–2 mm; Ae. comosa ssp. heldreichii: 4–6 mm; Ae. geniculata: 7 Table 1.3 Species key of the genus Aegilops. ¼ species key” 1 Spikes long, more than 10 times as long as wide (excluding awns), if somewhat less, than 5 or more spikelets per spike 2 10 Spikes shorter (by shortening of the rachis internodes or by reduction of the number of spikelets), less than 8 times as long as wide (excluding awns), if somewhat more, than 3 or less spikelets per spike 18 2 Spike completely without awns or teeth (examine the terminal spikelet!), lemma rounded at the apex, glumes truncate, spikelets glabrous (Agropyron like) or with white erect bristles (ventricose in appearance) Subgenus Amblyopyrum Aegilops mutica Boiss. with ssp. mutica and ssp. loliacea (Jaub. et Sp.) Zhuk. 20 Spike with awns or teeth (examine the terminal spikelet!) 3 3 Glumes without awns, sometimes with teeth or one short thin awn 4 30 Glumes at least of the terminal spikelets with longer awns 13 4 Spike long, often distinctly two-rowed, at least apical lemma awned (1 awn), lemma in the upper part flat, (forms with many awns similar to diploid 5 wild Triticum species), glumes often conspicuously keeled, without awns Subgenus Sitopsis 40 Spike cylindrical or somewhat tapering towards the apex 8 5 Glumes with little lateral tooth and emarginate upper rim, often with skinny lateral rim Ae. speltoides Tausch with ssp. speltoides and ssp. ligustica (Savign.) Zhuk. 50 Glumes with 2 distinct lateral teeth, separated by a obtuse angle, upper rim of the glume flat 6 6 Spike relatively small, delicate, internodes of the rachis short, spikelets 5.5–8.5 mm long, awns present, teeth absent, plants small, up to 20 cm 7 60 Spike bigger, internodes of the rachis elongated, spikelets 8 – 13 mm long, awns and 1 or 2 teeth present, plants more than 20 cm Ae. longissima Schweinf. et Muschl. (only apical spikelets extending into awns) and Ae. sharonensis Eig (awns throughout spike) 7 All spikelets with awns of more or less equal length Ae. bicornis (Forssk.) Jaub. et Sp. 70 Only terminal spikelets with long awns, one awn curved, very long Ae. searsii Feldman et Kislev ex K. Hammer 8 Spikelets ventricose, spike moniliform, glumes with 2 marginal teeth, mostly glabrous Subgenus Aegilops Ae. ventricosa Tausch 80 Spikelets not or scarcely ventricose, spike not or scarcely moniliform 9 (continued) 8 Table 1.3 (continued) 9 Spikes and spikelets relatively slender (awnless forms of awned species) 10 90 Spikes and spikelets relatively stout 11 10 Teeth of glumes and lemma relatively broad at the base Ae. peregrina (Hackel) Maire et Weiller ssp. brachyathera (Boiss.) Maire et Weiller (ssp. cylindrostachys (Eig et Feinbrun) Maire et Weiller, nom. illeg.) 100 Teeth of glumes and lemma not broad at the base Ae. triuncialis L. var. anathera Hausskn. et Bornm. 11 Glumes hairy 12 110 Glumes glabrous, without teeth (very seldom with little teeth or 1 little short awn) Ae. tauschii Coss. with ssp. tauschii and ssp. strangulata (Eig) Tzvel. 12 Glumes with long teeth, mostly 6 or less spikelets per spike Ae. juvenalis (Thell.) Eig 120 Glumes with 1–4 short teeth, mostly 7 or more spikelets per spike Ae. crassa Boiss. (4x and 6x) and Ae. vavilovii (Zhuk.) Chennav. (6x) 13 Upper spikelets sterile, 3 fertile and 3 sterile spikelets per spike, vestigial basal spikelets (2)–3 –(4), lemma awned, at least with some spikelets, glumes more than 11 mm long, mostly with 2 awns, one with broad base, this awn often divided Ae. columnaris Zhuk. 130 Upper spikelets fertile 14 14 Glumes with 1 awn, often only at the upper spikelets 15 140 Glumes with more than 1 awn, often 2 or 3 16 15 Glumes of the terminal spikelets with 1 awn and 2 teeth (very seldom without awn), spike cylindrical, scarcely tapering towards the apex Ae. cylindrica Host 150 Glumes of the terminal spikelets without teeth, spike tapering markedly towards the apex Ae. markgrafii (Greuter) K. Hammer 16 Spikes relatively small, delicate, veins of the glumes parallel Ae. kotschyi Boiss. 160 Spikes bigger, veins not parallel 17 17 Awn base in relation to awn length very broad Ae. peregrina (Hackel) Maire et Weiller 170 Awn base not very broad, 5–6 fertile spikelets per spike, vestigial basal spikelets mostly 3, lemma awns mostly absent Ae. triuncialis L. with ssp. triuncialis and ssp. persica (Boiss.) Zhuk. 18 Upper spikelets sterile, conspicuously smaller in size than lower spikelets 19 180 Upper spikelets fertile, sometimes little smaller in size than lower spikelets, terminal spikelet always with grain 20 (continued) B. Kilian et al. Table 1.3 (continued) 19 Glumes with 2 or 3 awns, glumes less than 11 mm in length (cf. Ae. columnaris) Ae. neglecta Req. ex Bertol. with ssp. neglecta (4x) and ssp. recta (Zhuk.) K. Hammer (6x) 190 Glumes with more than 3 awns Ae. umbellulata Zhuk. with ssp. umbellulata and ssp. transcaucasia Dorof. et Migusch. 20 Glumes with only 1 awn, mostly 2 spikelets per spike Ae. uniaristata Vis. 200 Glumes with more than 1 awn 21 At least 1 glume of the terminal spikelet with 2 awns Ae. comosa Sibth. et Sm. with ssp. comosa and ssp. heldreichii (Boiss.) Eig (syn.: var. subventricosa Boiss.) 210 Glumes of all spikelets mostly with more than 2 awns 22 Glumes with mostly more than 3 awns Ae. geniculata Roth with ssp. geniculata and ssp. gibberosa (Zhuk.) K. Hammer 220 Glumes with (2)–3 awns 23 Awns of the glumes relatively to awn length very broad Ae. peregrina (Hackel) Maire et Weiller (ssp. peregrina) 230 Awns of the glumes not very broad at the base 24 Glumes with 2–(3) awns, glumes with conspicuous non-parallel veins, spikelets relatively big, 2–(3) spikelets per spike Ae. biuncialis Vis. 240 Glumes with (2) – 3 awns, glumes with parallel veins, spikelets relatively small, more than 3 spikelets per spike Ae. kotschyi Boiss. 21 22 23 24 4–8 mm; Ae. juvenalis: 4–6 mm; Ae. kotschyi: 1–2 mm; Ae. neglecta: 2–3 mm; Ae. peregrina: 2–4 mm; Ae. umbellulata: 1–3 mm; Ae. triuncialis: 3–6 mm. These are good key characters, at least for material from the eastern Mediterranean region. 1.2.4 Brief Description of the Aegilops Species For more details, see Hammer (1980a, b) and van Slageren (1994). 1 Aegilops 9 Aegilops mutica Aegilops mutica Boiss. – Amblyopyrum muticum (Boiss.) Eig (Figs. 1.1 and 1.2)1 Annual, outcrossing with long slender spikes. Plants 30–90 cm tall. Spikes not awned, 5–13 cm long, upper florets more or less reduced. Spikelets 5–8 flowered. Glumes 4–9 mm long, hairy (common variant, ssp. mutica), or glabrous (rare variant, ssp. loliacea (Jaub. et Sp.) Zhuk.). Mixed populations occur locally. Hammer (1980b) differentiates the variants on the var. level. Van Slageren (1994) also prefers the var. level but in the separate genus Amblyopyrum. Van Slageren (1994) distinguished Amblyopyrum from Aegilops by several morphological characters, e.g., awnless linear spikes. Genome: T. Aegilops mutica occurs only in central Turkey and Armenia, frequently on roadsides, the edge of cultivation, dry hillsides, and grassy steppes. Uncommon. Fig. 1.1 Spike morphology of Aegilops mutica (AE374 – IPK Genebank accession number AE 374) Fig. 1.2 Distribution of Aegilops mutica 1 AE numbers refer to IPK Genebank Aegilops accession numbers. GIS distribution maps are based on van Slageren (1994) and our own observations. More information about the accessions can be obtained from http://gbis.ipk-gatersleben.de/gbis_i/. 10 Aegilops speltoides B. Kilian et al. Aegilops speltoides Tausch – Sitopsis speltoides (Tausch) Löve, Triticum speltoides (Tausch) Gen. et Richt (Figs. 1.3–1.6). Annual, outcrossing with long slender spikes. Plants 20–70 cm tall. Spikes 3–25 cm long (excluding awns), with 6–13 spikelets. Glumes 5–9 mm long. Florets 4, muticous or 1-awned. Uppermost spikelet with 2 lower lemmas, each with a setaceous 2–12 cm Fig. 1.3 Ear morphology of Aegilops speltoides ssp. speltoides (AE 378) Fig. 1.5 Ear morphology of Aegilops speltoides ssp. ligustica (AE 1611) Fig. 1.4 Distribution of Aegilops speltoides ssp. speltoides Fig. 1.6 Distribution of Aegilops speltoides ssp. ligustica 1 Aegilops long awn. Lateral spikelets either lacking awns, axis persistent in fruit (ssp. speltoides) or with awns, axis disarticulating in fruit [ssp. ligustica (Savign.) Zhuk.]. Both variants are interfertile and sympatric, except towards the limit of the species’ distribution. Separated on the var. level by van Slageren (1994): var. speltoides and var. ligustica (Savign.) Fiori. For both subspecies, two botanical varieties each are indicated by Hammer (1980b). Genome: S. The northern and eastern parts of the Fertile Crescent are the major area of occurrence. The species is less common in central and western Turkey. Several adventive sites exist outside the Fertile Crescent. The species is mainly found in grasslands and moderately disturbed sites. Also found in open Pinus and Quercus forests. Soil texture: clay and loams, as well as more pure sands. Wide variation for soil type has been observed. Recorded rainfall data are between 450 and 1,450 mm annually. Massive stands on basaltic slopes in open oak park-forest along the foothills of the Taurus and Zagros mountains. From sea level up to 2,000 m. 11 6–8 mm long. Apex of lower lemmas in apical spikelet extending (each) into 6–13 long diverging awns, with lateral spikelets lacking. Ankory and Zohary (1962) report hybrids between Ae. longissima and Ae. sharonensis. Genome: Sl. Distributed in coastal Egypt, Israel/Palestine and northwestern Jordan. Uncommon to rare. On sandy soils and sandstones. Present in sand, sandstone, sandy loams; edges of cultivation and roadsides, often together with Ae. sharonensis. In Jordan on Aegilops longissima Aegilops longissima Schweinf. et Muschl. – Triticum longissimum (Schweinf. et Muschl.) Bowden, Sitopsis longissima (Schweinf. et Muschl.) Löve (Figs. 1.7 and 1.8). Annual with long slender spikes. Plants erect, 30–70 cm tall (excluding spikes). Spikes 10–20 cm long (excluding awns), with 8–17 spikelets. Apical spikelets extending into a 6–13 cm long awn. Glumes Fig. 1.8 Distribution of Aegilops longissima Fig. 1.7 Ear morphology of Aegilops longissima (AE 320) 12 limestone with terra rossa. It is also known from dry grasslands and abandoned fields. Annual rainfall from 250 to 400 mm. From 200 m up to 600 m. Aegilops sharonensis Aegilops sharonensis Eig – Triticum sharonense (Eig) Feldman et Sears, Ae. longissima Schweinf. et Muschl. ssp. sharonensis (Eig) Chennav. Sitopsis sharonensis (Eig) Löve (Figs. 1.9 and 1.10). Fig. 1.9 Ear morphology of Aegilops sharonensis (AE 315) Fig. 1.10 Distribution of Aegilops sharonensis B. Kilian et al. Annual with long slender spikes. Plants erect, 30–70 cm tall (excluding spikes). Spikes 10–20 cm long (excluding awns), with 8–17 spikelets. Apical spikelets extending into a 6–13 cm long awn. Glumes 6–8 mm long. Apex extending into awns up to 9 cm at the apical spikelet, lateral spikelets in short awns in base of spike, rapidly increasing upward to 3–7 cm. Genome: Ssh. Endemic to the coastal plains of Israel and south Lebanon. Very limited distribution (200 15 km). In its area, however, it is reported to be common and occurring sometimes in dense stands. Found on dry open grassland and consolidated sand dunes. On sand, sandy loam or marine diluvium bedrock. From sea level up to about 100 m. 1 Aegilops Aegilops bicornis Aegilops bicornis (Forssk.) Jaub. et Sp. – Triticum bicorne Forssk., Sitopsis bicornis (Forssk.) Löve (Figs. 1.11 and 1.12). Annual with slender spikes. Plants erect, 20–40 cm tall (excl. spikes). Spikes 4–7.5 cm long (excluding awns), with 8–15 ( 19) spikelets. Apex of lemmas of fertile florets with 0.3–0.4 cm long awn in basal spikelets, in the upper part of the spike up to 4.5–6 cm in length (var. bicornis). In var. anathera Eig [var. Fig. 1.11 Ear morphology of Aegilops bicornis (AE 1079) Fig. 1.12 Distribution of Aegilops bicornis 13 mutica (Aschers.) Eig], only the lemmas of the upper 5–7 spikelets are awned. Genome: Sb. Distributed on the coastal regions of Cyprus, Libya, Egypt, and Israel/Palestine, some parts of southern Jordan. A few locations in inland Syria. It is mainly found in grasslands, under palms, pines, in plantations, and on edges of wheat fields. In the coastal areas, it is found on lowland areas of sandy loams and stabilized sand dunes. On light sandy, sandy calcareous, or sandstones, average rainfall 75–275 mm annually. At the altitude of 200 m from sea level, but in Jordan found up to the level of 700–900 m. 14 Aegilops searsii Aegilops searsii Feldman et Kislev ex K. Hammer – Sitopsis searsii (Feldman et Kislev ex K. Hammer) Löve, Triticum searsii (Feldman et Kislev) Feldman et Kislev, nom. inval (Figs. 1.13 and 1.14). Annual with slender spikes. Plants (10 ) 15–35 cm long (excluding spikes). Spikes 6.5–13.5 cm long (excluding awns), with 7–10 ( 14) spikelets. Glumes 6–8 mm long. Florets 2–4. Apex of the 2 lower, apical lemmas flat, extending into distinctly different awns, Fig. 1.13 Ear morphology of Aegilops searsii (AE 1071) Fig. 1.14 Distribution of Aegilops searsii B. Kilian et al. one of the fertile floret well developed, 5–13 cm long, the one of the sterile floret only 1.5–7 cm long. Genome Ss Limited to Israel/Palestine, Syria, Jordan, and Lebanon. Uncommon throughout its range. A species of hills and mountainous regions. In dry open grasslands, steppe, ruderal fields, and roadsides. Almost exclusively on limestone, only rarely on basalt or sandstone. Soil texture includes clay and loam, more rarely sand and terra rossa. Annual rainfall data of 150–300 ( 500) mm. From 450 to 1,600 m in Jordan, Lebanon and Syria. In Israel/Palestine just reaching the eastern end of the coastal plain and occurring lower to around 100 m. 1 Aegilops Aegilops markgrafii Aegilops markgrafii (Greuter) K. Hammer – Aegilops caudata auct. non L., Triticum markgrafii Greuter. The proposal of Scholz and van Slageren (1994) to conserve Ae. caudata failed (Figs. 1.15 and 1.16). Annual with slender spikes. Plants 25–50 cm tall. Spikes 4–11 cm long (excluding awns), with 3–9 spikelets. Glumes 9–11 mm long. At the uppermost spikelets glumes each tapering into divergent awn, Fig. 1.15 Ear morphology of Aegilops markgrafii (AE 1399) Fig. 1.16 Distribution of Aegilops markgrafii 15 4–10 cm long (1–1.5 mm broad at base), lacking basal teeth. Vestigial spikelets 2. Lateral spikelets toothed (var. markgrafii) or one of the teeth setaceous awned [var. polyathera (Boiss.) Hammer]. Morphological variation limited. Genome: C. Naturally occurring mainly in Aegean and western Turkey, where growth can be abundant. Less common and more sporadic in inland Turkey and along the Fertile Crescent. Found on roadsides, grassland including steppe, edges of and within fields of cultivation, various forest types. Often on dry, rocky, slopes of limestone, more rarely on shales, schist, sandstone or granite. Soil texture pre-dominantly clay and sandy loams. Aegilops markgrafii can form dense stands, often together with other Aegilops species. Collected annual rainfall data indicate a range of 300–700 mm. From sea level up to 1,850 m. 16 Aegilops biuncialis Aegilops biuncialis Vis. – Triticum biunciale (Vis.) Richter, nom. illeg., Aegilops lorentii Hochst., Triticum lorentii (Hochst.) Zeven, Triticum macrochaetum (Shuttlew. et A. Huet. ex Duval-Jouve) Richter (Figs. 1.17 and 1.18). Many-tillered annual with short spikes. Plants 10–40 cm tall (excluding spikes). Spikes 1.5–3.5 cm long (excluding awns), with 2 (–3) fertile and 1 (–2) rudimentary spikelets. Glumes 8–10 mm long. Spikes breaking off as a unit. Apical spikelet always with 3 awns, up to 4–7 cm long. Some variation, e.g., in the pubescence of glumes (see Hammer 1980a). Genome: UM. Fig. 1.17 Ear morphology of Aegilops biuncialis (AE 1430) Fig. 1.18 Distribution of Aegilops biuncialis B. Kilian et al. Mainly in the Aegean, also Turkey, Bulgaria, Cyprus, the western part of Fertile Crescent, in the eastern Cis-, and Transcaucasia, and in the southern part of the Crimea and adjacent parts of Russia and the Ukraine. Generally growing on dry areas, roadsides, edges of cultivation and various forest types. Also in grasslands, maquis, steppe and dry, rocky mountain slopes. Extensive populations have been observed, e.g., in Daghestan. This species mainly grows on limestone and also on schists, shales, basalt, granite, and pillow lavas. Soil texture: mainly clay or sandy loam, or clay. Annual rainfall data indicate some drought tolerance, but the species also occurs in areas with as much as 1,250 mm. From 200 m in Jordan up to 1,750 m. 1 Aegilops Aegilops kotschyi Aegilops kotschyi Boiss. – Triticum kotschyi (Boiss.) Bowden, Aegilemma kotschyi (Boiss.) Löve (Figs. 1.19 and 1.20). Multitillered annual. Plants 10–30 cm tall (excluding spikes). Spike 0.5–4 cm long (excluding awns), with 2–6 fertile, and 2–3 vestigial spikelets. Spikes breaking off as a unit. Glumes of lower spikelet ovate-oblong, 4–5 mm long, with 3 (sometimes 2) awns, 2.5–4.5 cm long. Lemma awn half as long as those of glumes. Fig. 1.19 Ear morphology of Aegilops kotschyi (AE 1215) Fig. 1.20 Distribution of Aegilops kotschyi 17 Limited variation. Hammer (1980a) indicates five botanical varieties. Some forms are difficult to differentiate from Ae. peregrina (see key for both species, van Slageren 1994). Genome: SU. Along the coast of eastern North Africa and the western part of the Fertile Crescent. Locally common in this range. Extending into the Saharo-Arabian region to Kuwait and eastern Saudi Arabia. Usually in scattered populations, but sometimes in large stands. In dry wadis and sand dunes. Also known from steppe, wastelands, roadsides and dry grasslands, fields, plantations and woodlands. Predominantly on sandy soils but also on loss, gravel, sandy clays and loams, and light clayloams. Mainly on sandstone and limestone, less frequently on alluvium or maritime sands and occasionally basalt. Growing under 100–425 mm annual rainfall. From 300 m up to 1,550 m. 18 Aegilops triuncialis Aegilops triuncialis L. – Triticum triunciale (L.) Raspail, Aegilopodes triuncialis (L.) Löve (Figs. 1.21 and 1.22). Multitillered annual with subcylindrical spikes. Plants 20–30 cm tall (excluding spikes). Spike 2.5–6 cm long (excluding awns), with 3–5 fertile and (2–) 3 rudimentary spikelets. Spikes breaking off as a unit. Glumes of lateral spikelets with 2–3 awns, 1.5–6 cm long. Central awn of apical glumes 5–8 cm long, lateral awns 1–3 cm Fig. 1.21 Ear morphology of Aegilops triuncialis (AE 1652) Fig. 1.22 Distribution of Aegilops triuncialis B. Kilian et al. long (ssp. triuncialis). In ssp. persica (Boiss.) Zhuk. the lateral awns are reduced to teeth or short awns. Genome: UC. Occurring all over southern Europe and the Near East, extending eastwards into Central Asia. Wellrepresented along the entire Fertile Crescent. Also found in Cyprus and the southern Crimea as well as in Cis-Caucasia. Common throughout its range. Introduced in the US and a weed on rangeland. In Europe found as an adventive in several countries. Locally abundant in generally dry, somewhat disturbed habitats, and dry rocky slopes of hills and mountains. Also present on edges of and within cultivation. Vegetation types include garrigue, maquis, grassland, shrub- and wood-lands, (open) forests. Also found in the steppe up to the margin of the desert but more rarely also in humid pastures, river terraces, and even at the seaside. Predominately on limestone and basalt, but also on shales, pillow lava, silicate, terra rossa, karsts, schist, and sandstone. Soil texture also varies widely, but the species grows mainly on clay- and sandy loam. As a typical colonizer, the species can be found in massive stands and dominate the vegetation. Together with Ae. geniculata, this is the most widespread species of the genus Aegilops and grows under a similarly wide annual rainfall amplitude, varying from 125 mm up to 1,400 mm. From sea level up to 2,700 m in Morocco. 1 Aegilops Aegilops cylindrica Aegilops cylindrica Host – Triticum cylindricum Ces., Pass. et Gib., Cylindropyrum cylindricum (Host) Löve (Figs. 1.23 and 1.24). Annual with slender spikes. Plants 20–40 (–80) cm tall. Spikes 5–7 (–10) cm long (excluding awns), with 5–7 (–9) spikelets. Glumes 8–9 mm long. Uppermost Fig. 1.23 Ear morphology of Aegilops cylindrica (AE 1614) Fig. 1.24 Distribution of Aegilops cylindrica 19 spikelet with 3–4 small awns arising from glumes and lemmas. Outer glume 2-toothed at base of awn. Spike falling entire or mostly disarticulating into cylindrical spikelets. Vestigial spikelets 1–2. Four botanical varieties are indicated by Hammer (1980b), most on the basis of presence/absence of awns. Genome: DC. Widespread, with tendency to weedy behavior. Occurring mainly westward from Turkey into Bulgaria, Romania, the Balkans, and into Hungary, northward into the Caucasus region and along the Black Sea coast, and eastward into Central Asia. In the Fertile Crescent, mainly present in the northern part. Introduced in the US and present in many states. A species from ruderal and disturbed sites, dry hilland mountain slopes, grasslands, and close by or within cultivation. Soil bedrock is mainly calcareous and basaltic, less frequently on sands. Soil textures include clay, clayloams, but also on more pure sands. Annual rainfall data from 450 to 800 mm. Aegilops cylindrica may grow in large stands after recent disturbances. From 28 m up to about 2,000 m. 20 Aegilops tauschii B. Kilian et al. Aegilops tauschii Coss. – Triticum tauschii (Coss.) Schmalh., Aegilops squarrosa auct. non L., Patropyrum tauschii (Coss.) Löve (Figs. 1.25–1.27). Annual with slender spikes. Plants 30–40 cm tall. Spikes 5–7 cm long (excluding awns), with 9–11 spikelets. Lateral spikelets barrel-shaped, usually disarticulating. Uppermost spikelet with unawned glumes. Lower lemmas bearing slender awn up to 3–4 cm long. Spikes slightly constricted between the barrel-shaped spikelets (ssp. tauschii) or constricted between the ventricose spikelets (ssp. strangulata). A number of morphological variants are indicated by Hammer (1980b). Genome: D. Almost exclusively east of the 40 longitude. Its center of distribution is along the southern shores of the Caspian Sea and in Azerbaijan. This species is the Fig. 1.25 Ear morphology of Aegilops tauschii ssp. tauschii (AE 1650) Fig. 1.26 Ear morphology of Aegilops tauschii ssp. strangulata (AE 1605) Fig. 1.27 Distribution of Aegilops tauschii (both subspecies) 1 Aegilops only diploid Aegilops that has spread mainly eastwards from the center of origin of the genus. Aegilops tauschii is the only species known with certainty from China. A species of wide ecological amplitude, known from dry grasslands, fallow, steppes, and moderately disturbed sites, roadsides, and edges of and within cultivation. But also found in woodlands and marginal forests, degraded forests, on stony slopes, in irrigated fields and river valleys, and in humid forests along the southern belt of the Caspian Sea. Predominantly on basalt, the soil texture is mainly loam, sandy loam, clayloam, or sandy clay. Aegilops tauschii is able to grow on silty soils. Rainfall data indicated a range of 150–350 mm annually, sometimes even below 100 mm. From sea level up to 2,700 m. 21 spikes. Both species occur sympatric and are robust and drought-tolerant. Three varieties of ssp. crassa are indicated by Hammer (1980b). Genome: Ae. crassa ssp. crassa (4x) DM; Ae. crassa ssp. crassa (6x) DDM. Occurring in central, western, and northwestern Iran, in central and northern Iraq, northern Afghanistan, Aegilops crassa Aegilops crassa Boiss. – Triticum crassum (Boiss.) Aitch. et Hemsl., Gastropyrum crassum (Boiss.) Löve (Figs. 1.28 and 1.29). Annual with long slender spike. Plants 30–50 cm tall. Spikes 6–9 cm long, adpressed velutinous, disarticulating. Glumes 8–10 4–5 mm, subtruncate. Lemmas 2-toothed, those of upper spikelets often broadly awned. Uppermost spikelet narrower than lateral one. Glumes short toothed. It is difficult to differentiate Ae. crassa (tetraploid and few hexaploid races) with moniliform spikes from the hexaploid Ae. vavilovii (Zhuk.) Chennav. with narrowly cylindrical Fig. 1.29 Distribution of Aegilops crassa Fig. 1.28 Ear morphology of Aegilops crassa (AE 244) 22 southernmost parts of Kazakhstan, western Kyrgyzstan, southern Turkmenistan and Uzbekistan, northern Tajikistan, as well as in northern and northeastern Syria and southern Turkey. Records from Jordan and Lebanon. A drought-tolerant species that grows under 150–350 mm annual rainfall in steppe, fallow, arid grasslands, along roadsides, within as well as in margins of cultivation and on rocky slopes. Mainly found on limestone, more rarely on basalt. Soil textures including clay and sandy loam and sand. From 260 m up to 1,650 m. B. Kilian et al. A species of roadsides, fallow, grasslands, and edges of and within cultivated areas. Populations of Ae. vavilovii can predominantly be found on limestone, more occasionally also on basalt, flint, or sandstone. The majority of rainfall data in the range of 100–275 mm, but up to 550 mm is recorded in some higher locations. From 275 m up to 1,550 m. Aegilops vavilovii Aegilops vavilovii (Zhuk.) Chennav. – Triticum syriacum Bowden, Gastropyrum vavilovii (Zhuk.) Löve, Ae. crassa var. palaestina Eig, Ae. crassa ssp. vavilovii Zhuk (Figs. 1.30 and 1.31). Annual with long slender spike. Plants 20–60 (–75) cm tall excluding spikes. Spikes narrowly cylindrical, tapering in upper half. Spikes (7.5–) 10–15 cm long excluding awns, with (5–) 7–10 spikelets. Rudimentary spikelets absent, rarely 1–2. Glumes adpressedvelutinous, the apex with 2–3 teeth. Lateral lemma apex with sharp tooth at the keel. Caryopsis adherent. Genome: DMS (DM S). Predominantly occurring in Jordan, Palestine/ Israel, and Lebanon. Also found in southern Turkey and in Iraq. Uncommon throughout its range and rare in Turkey and Iraq. Few isolated sites are known from Saudi Arabia, but they are probably resulting from introduction. Fig. 1.31 Distribution of Aegilops vavilovii Fig. 1.30 Ear morphology of Aegilops vavilovii (AE 1581) 1 Aegilops 23 Aegilops ventricosa Aegilops ventricosa Tausch – Triticum ventricosum (Tausch) Ces., Pass. et Gib., Gastropyrum ventricosum (Tausch) Löve (Figs. 1.32 and 1.33). Annual with long slender spike. Plants 40 (–65) cm tall (excluding spikes). Spikes 5–12 cm long (excluding awns), with (3–) 6–11 spikelets. Spikes distinctly moniliform. Glumes 7–8 mm long. Apical spikelets extending into a 4 cm long awn. Spikelets of barrel type, disarticulating at maturity. Hammer (1980b) accepts three morphological races on the level of botanical variety. Van Slageren (1994) calls them “former subvar.” Genome: DN. Occurring north and northwest of the Sahara, in the Iberian Peninsula, and in southern France, Corsica, Sardinia, and some other parts of southern Italy (Pignone et al. 1992). Uncommon throughout its range. A species of grasslands, roadsides, sandy wadis, and edges of and within cultivation. Also found in shrubs of Pistacia and Juniperus and oak forests. This species can be found predominantly on soils with a limestone bedrock, far less on basalt or sandstone. Recorded soil textures include mainly clay and sandy loams. Growth on very poor, stony soils, as well as on saline locations, and even marshy riversides reported. Rainfall data vary widely: from less than 100 mm up to 600 mm. From sea level up to 1,850 m. Fig. 1.32 Ear morphology of Aegilops ventricosa (AE 1568) Fig. 1.33 Distribution of Aegilops ventricosa 24 Aegilops juvenalis Aegilops juvenalis (Thell.) Eig – Triticum juvenale Thell., Aegilonearum juvenale (Thell.) Löve (Figs. 1.34 and 1.35). Annual with medium long spikes. Plants 10–35 cm tall (excluding spikes). Spikes 3–7 cm long (excluding awns), with 3–6 spikelets, cylindrical to slightly moniliform. Glumes adpressed velutinous, lateral glumes with 2 widely spaced awns. Spikelets cylindrical to urceolate, 8–13 mm long. Glumes 2-toothed, lemmas Fig. 1.34 Ear morphology of Aegilops juvenalis (AE 91) Fig. 1.35 Distribution of Aegilops juvenalis B. Kilian et al. with a long awn flanked at the base by 2 teeth or short awns. Hammer (1980b:235) maintained Ae. turcomanica Roshev. as a separate species based on Bowden’s (1959) remark that Ae. turcomanica should be tetraploid and, therefore, different from the hexaploid Ae. juvenalis. So far, no new tetraploid material has been found to reestablish Ae. turcomanica (see also van Slageren 1994). Genome: DMU (DM U). Occurring at rather dispersed locations in Central Asia (Turkmenistan, Uzbekistan) as well as in Azerbaijan and in the northern part of the Fertile Crescent. Rare throughout its range. In steppe, dry roadsides, grasslands, cultivated fields, and hillsides. Found on clay but probably also on other soil textures. Recorded annual rainfall from only 250–350 mm. From 140 m up to 1,000 m. 1 Aegilops Aegilops comosa Aegilops comosa Sm. in Sibth. et Sm. – Triticum comosum (Sm. in Sibth. et Sm.) K. Richt., Comopyrum comosum (Sm. in Sibth. et Sm.) Löve (Figs. 1.36 and 1.37). Annual, slender plants, 15–40 cm tall (excluding spikes). Spikes cylindrical, 1.5–3 cm long (excluding Fig. 1.36 Ear morphology of Aegilops comosa (AE 1376) Fig. 1.37 Distribution of Aegilops comosa 25 awns). 1–3 lateral spikelets, only top spikelet longawned. Glumes of uppermost spikelet each with 3 awns, the middle one 3–10 cm long, the lateral ones shorter. Spikes narrowly cylindrical, glumes with slender, parallel veins (ssp. comosa var. comosa according to van Slageren 1994). Spikes stout, glumes with prominent veins, bowed outwards [ssp. heldreichii (Holzm. ex Boiss.) Eig, according to van Slageren (1994) var. subventricosa Boiss.)]. For both subspecies, 4 botanical varieties each are indicated by Hammer (1980b). Genome: M. Occurring in coastal regions of the former Yugoslavia, Albania, and coastal and inland Greece. Rare throughout its range but more common in Greece. On roadsides, grasslands, and hillsides, in garrigue, and sometimes in cultivated fields. Mainly on limestone with clayloam soil texture. Rarely on saline soils. From sea level up to 500 m, rarely to 800 m. 26 Aegilops uniaristata Aegilops uniaristata Vis. – Triticum uniaristatum (Vis.) K. Richter, Chennapyrum uniaristatum (Vis.) Löve (Figs. 1.38 and 1.39). Annual with medium long spikes. Plants 20–40 cm tall (without spikes). Spikes 1–2.5 cm long (excluding awns), with 3–4 spikelets. Each glume of uppermost spikelet with 3–4 cm long awn and 2 small lateral teeth at base. Lateral spikelets with prominent veins. The Fig. 1.38 Ear morphology of Aegilops uniaristata (AE 576) Fig. 1.39 Distribution of Aegilops uniaristata B. Kilian et al. whole spike breaking off as a unit. Limited morphological variation. Genome: N. Occurring in coastal Croatia, Greece, Albania, and rarely in Italy. Uncommon to rare throughout its range. Van Slageren (1994) considered the species as extinct or extremely rare in Turkey. In dry grasslands and bushy slopes, mainly on rocky, calcareous soils, more rarely on sandstone. From sea level up to about 750 m. 1 Aegilops Aegilops umbellulata Aegilops umbellulata Zhuk. – Triticum umbellulatum (Zhuk.) Bowden, Kiharapyrum umbellulatum (Zhuk.) Löve (Figs. 1.40 and 1.41). Annual with short spikes. Plants 10–30 cm tall (without spikes). Spikes 3–5 cm long (without awns), with 2 fertile spikelets. Spike breaking off as a unit. Vestigial spikelets 3. Glumes with 3–7 setaceous, 20–35 mm long awns. Two lower lemmas excerted from glumes, bearing awns. Glumes with 5–7 awns (ssp. umbellulata), glumes with 3–4 awns (ssp. transcaucasica Dorof. et Migusch.). A special key for distinguishing this species from Fig. 1.40 Ear morphology of Aegilops umbellulata (AE 1616) Fig. 1.41 Distribution of Aegilops umbellulata 27 Ae. geniculata is provided by van Slageren (1994). Genome: U. Predominantly occurring in Turkey but also present along most of the Fertile Crescent, in Transcaucasia and Iran. Uncommon throughout its range. A species of fallow, grasslands, roadsides, margins of cultivation and of edges, and within forests and plantations. In Greece found at the seaside on sandy dunes. This species mainly grows on shallow, rocky soils with bedrock consisting predominantly of limestone or basalt. Soil textures recorded are clay and sandy loams, with more pure clay and loam, terra rossa and alluvium, gravel. Annual rainfall data vary between 350 and 700 mm. From sea level up to 1,800 m. 28 Aegilops peregrina Aegilops peregrina (Hackel) Maire et Weiller – Aegilops variabilis Eig, Triticum peregrinum Hackel, Aegilemma peregrina (Hackel) Löve (Figs. 1.42 and 1.43). Annual with medium long spikes. Plants 15–40 cm tall (excl. spikes). Spikes 1.5–5 cm long (excluding awns), with (2–) 3–5 fertile and (2–) 3 rudimentary spikelets. Spikes breaking off as a unit, rudimentary spikelets remaining attached to the culm. Glumes 3–5 mm, with veins somewhat unequally spaced and 2–3 unequally wide and long awns. Lemma apex with 1–2 awns and 1–2 uneven teeth. A race with cylindrical spike (five and more spikelets per spike) and mostly without awns is var. brachyathera (Boiss.) Maire et Weiller, considered by Hammer (1980a) as a subspecies [ssp. cylindrostachys (Eig et Feinbrun) Maire et Weiller, nom. illeg. ¼ var. brachyathera]. Fig. 1.42 Ear morphology of Aegilops peregrina (AE 1610) Fig. 1.43 Distribution of Aegilops peregrina B. Kilian et al. The typical ssp. peregrina has ovoid spikes and mostly awns. Ten races of the variety level are indicated by Hammer (1980b) for this very variable species. Genome: SU. Occurring abundantly in Israel/Palestine, western Jordan, Lebanon, and western Syria. Uncommon to rare in Turkey, some Greek islands, Iraq, Azerbaijan, coastal Egypt, and Cyprus. Extending eastward into Iran. A species from dry, ruderal sites in coastal areas and hill and mountain slopes. In garrigues, semi-steppe, open Quercus and Pinus forests, as well as plantations. The predominant bedrock is limestone. Rainfall data in the range of 150–350 mm only in annual rainfall varying from 300 to 800 mm. Ae. peregrina is also reported from mountainous locations in Lebanon, Syria, and Turkey that receive as much as 1,300 mm annually. From 380 up to 1,600 m. 1 Aegilops Aegilops columnaris Aegilops columnaris Zhuk. – Triticum columnare (Zhuk.) Morris et Sears, comb. inval (Figs. 1.44 and 1.45). Multitillered annual. Plants 20–50 cm tall (excluding spikes). Spike 2–4 cm long (excluding awns). Lower 2–3 spikelets fertile, upper 2 ones sterile, smaller. Spikes breaking off as a unit. Vestigial spikelets 3. Glumes of fertile spikelet 7–11 mm long, with 2–3 awns. Lemmas with 2–3 setulose awns, more slender and shorter than the glume awns. The species shows a limited morphological variation. Sometimes, it is difficult to be distinguished from Ae. neglecta. For a special key, see van Slageren (1994). Genome: UM. Fig. 1.44 Ear morphology of Aegilops columnaris (AE 1587) Fig. 1.45 Distribution of Aegilops columnaris 29 Occurring mainly in Turkey and the western Fertile Crescent, but scattered in the eastern part of the arc as well. The area of distribution extends westwards to Crete, eastwards to Armenia and Azerbaijan, rare in Iran. Uncommon throughout its range. In dry open fields, road- and hillsides, more rarely in forests. Mainly found on limestone, less frequently on basalt. Soil textures are predominantly stony, with additional clay, clay loam and occasionally sand. The range of annual rainfall data 450–1,250 mm. From 450 m up to 1,990 m, only occasionally lower than 450 m but also found at sea level. 30 Aegilops neglecta Aegilops neglecta Req. ex Bertol. – Aegilops triaristata Willd., nom. illeg., Triticum neglectum (Req. ex Bertol.) Greuter (Figs. 1.46–1.48). Multitillered annual. Plants 25–35 cm tall (excluding spikes). Spike 3–6 cm long (including erectopatent awns), with 2 fertile and 1–2 upper sterile spikelets. Spikes breaking off as a unit. Vestigial spikelets (2–) 3. Glumes of lower spikelets ovate-elliptic, 9–10 cm long. Awns 2–3, 2–5 cm long, broad at base, setaceous above. Fig. 1.46 Ear morphology of Aegilops neglecta ssp. neglecta (AE 369) B. Kilian et al. The tetraploid (ssp. neglecta) and hexaploid races [ssp. recta (Zhuk.) Hammer] are difficult to distinguish (van Slageren 1994). But there are some indications, e.g., Hammer (1980b), Kimber and Feldman (1987). More variation on the tetraploid level is described by Hammer (1980b). Genome: Ae. neglecta ssp. neglecta: UM; Ae. neglecta ssp. recta: UMN. Occurring from Portugal to Turkey and into Turkmenistan. Generally in dry, somewhat disturbed habitats and vegetation types such as fallow, grasslands, roadsides, stony fields, and hillslopes, maquis, garrigue, in forests or scrubs, as well as within and on the edges of cultivation. Occasionally found on river banks and generally more humid habitats. The parent rock is mainly limestone. Recorded soil textures include mainly loam, clayloam, and sandy loam. Collected Fig. 1.47 Ear morphology of Aegilops neglecta ssp. recta (AE 1648) Fig. 1.48 Distribution of Aegilops neglecta, both subspecies 1 Aegilops rainfall data vary from 450 to 750 mm, and in some sites it can be as high as 1,400 mm. From 200 m up to 2,000 m. Aegilops geniculata Aegilops geniculata Roth – Aegilops ovata auct. non L., Triticum ovatum auct. non Rasp., no valid name of this species exists under Triticum (van Slageren 1994) (Figs. 1.49 and 1.50). Multitillered annual. Plants 10–30 cm tall (excluding spikes). Spike 1.2–1.8 cm long (excluding awns), with 2 (–3) lower fertile spikelets and 1 uppermost sterile spikelet. Vestigial spikelets 1 (–2). Spikes breaking off as a unit. Glumes subventricose with (3–) 4–5 setaceous awns, 1.5–2.5 cm long. Lemma awns as long as those of glumes. Ssp. geniculata has more lax spikes and often more than 3 spikelets per spike, whereas ssp. gibberosa Zhuk. has very dense spikes and not more than 3 spike- 31 lets per spike. A number of botanical varieties of this variable species has been described (Hammer 1980b). Genome: MU. Common in southern Europe and the Aegaean but relatively rare in Turkey and Transcaucasia. Introduced in the Canary Islands. Adventive in parts of central and northeastern Europe. Locally abundant in generally dry, somewhat disturbed habitat such as fallow, wastelands, roadsides, and dry rocky slopes of hills and mountains. Also on edges of and within cultivation. Vegetation types include mainly garigue, maquis, grassland, shrub- and woodlands, forests and scrub and steppe. Bedrock is predominantly limestone. Soil texture also varies widely. Ae. geniculata can grow on very stony and rocky soils. As a typical colonizer, the species can be found in massive stands, especially at regularly disturbed places. Together with Ae. triuncialis, this is the most widespread species of the genus and grows under a similarly wide annual rainfall amplitude, varying from less than 100 mm up to 1,100 mm. Mainly from 300 m to 1,750 m. 1.3 Evolution of Aegilops and Triticum Fig. 1.49 Ear morphology of Aegilops geniculata (AE 1653) Fig. 1.50 Distribution of Aegilops geniculata Studies on Aegilops and Triticum evolution have attracted large attention over more than 150 years and have produced a large amount of literature. Selected studies in Aegilops–Triticum based on morphological, cytogenetical, and molecular studies are summarized in Table 1.4. Recent molecular studies on 32 B. Kilian et al. Table 1.4 Summary of published phylogenetic and diversity studies Field of interest References Morphology Morphology including hybrid fertility; pollen fertility Cytogenetics GISH Fluorescence in situ hybridization N-banding and genomic in situ hybridization C-banding Nuclear DNA content with flow cytometry Chloroplast markers and genes Plasmon Allozyme variation and variation in chloroplast DNA, 2Dprotein patterns, SS and 18-268 rRNA gene and spacer nucleotide sequences, and variation in repeated nucleotide sequences cp microsatellite Sequences Nuclear markers and genes Isozymes Electrophoretic analysis of alpha gliadins Intergenic spacer nor loci 50 External transcribed spacer SSCP RAPD RFLP AFLP EST unigenes genome specific amplified length and CAPS polymorphisms SSR and EST-SSR Inter-retroelement amplified polymorphism (IRAP) markers Sequences Sequences Ha locus only Sequences LMW and HMW only Zhukovsky (1928); Eig (1929); Sarkar and Stebbins (1956); Kihara (1954); Johnson (1975); Johnson and Dhaliwal (1976); Hammer (1980a, b); Kimber and Sears (1987); van Slageren (1994); Ohta (2000); Panajiotidis et al. (2000); Seberg and Frederiksen (2001); Matsuoka and Takumi (2007) Raskina et al. (2002) Raskina et al. (2004); Salina et al. (2006) Gill and Chen (1987) Gill and Kimber (1974); Friebe et al. (1992); Badaeva et al. (2002, 2004) Özkan et al. (2003, 2009) Tsunewaki et al. (1996, 2002) Dvorak and Zhang (1992) Provan et al. (2004); Gandhi et al. (2005); Matsuoka et al. (2005, 2008); Matsuoka and Takumi (2007) Gielly and Taberlet (1994); Miyashita et al. (1994); Kellogg et al. (1996); Vanichanon et al. (2003); Yamane and Kawahara (2005); Golovnina et al. (2007); Kilian et al. (2007a); Haider and Nabulsi (2008) Guadagnolo et al. (2001b); Kawahara (2002) Masci et al. (1992) Sallares and Brown (1999) Sallares and Brown (2004) Ohsako et al. (1996) Guadagnolo et al. (2001a, b); Khlestkina (2001); Goryunova et al. (2004) Takumi et al. (1993); Gielly and Taberlet (1994); Mori et al. (1995); Sasanuma et al. (1996); Dvorak et al. (1998b); Galili et al. (2000) Heun et al. (1997); Monte et al. (2001); Sasanuma et al. (2002, 2004); Kilian et al. (2007a) Dvorak and Akhunov (2005) Kadosumi et al. (2005) Lelley et al. (2000); Pestsova et al. (2000); Guadagnolo et al. (2001a, b); Adonina et al. (2005); Gandhi et al. (2005); Zhang et al. (2006) Saeidi et al. (2008) Kellogg et al. (1996); Wang et al. (2000); Allaby and Brown (2001); Faris et al. (2001); Huang et al. (2002); Vakhitov et al. (2003); Goryunova et al. (2005); Mason-Gamer (2005); Petersen et al. (2006); Baum et al. (2009) Kilian et al. (2007a); Massa and Morris (2006); Chalupska et al. (2008); Salse et al. (2008) Massa et al. (2004); Chantret et al. (2005); Massa and Morris (2006); Li et al. (2008a, b); Bhave and Morris (2008a, b) Gu et al. (2004, 2006); Long et al. (2005); Li et al. (2008a, b); Jiang et al. (2008) 1 Aegilops 33 phylogenetic relationships of Aegilops and Triticum species review also selected previous literature (Yamane and Kawahara 2005; Petersen et al. 2006). Morphological studies (including monographs) and collection expeditions by Zhukovsky (1928), Eig (1929), Kihara (1954), Hammer (1980a, b), Kimber and Sears (1987), and van Slageren (1994), among others, have provided detailed knowledge and various classification systems (Table 1.1). The great morphological variation displayed within many species in the Aegilops–Triticum group has been the cause for extensive recognition of taxa below the species rank and led to various opinions on their relationships (Hammer 1980a, b; van Slageren 1994). These studies also provided knowledge on the geographic distribution of the species and on their ecological requirements. The latest monograph on Aegilops has been published by van Slageren (1994). He summarized the current knowledge on morphological traits and concluded that Aegilops, Amblyopyrum and Triticum are separate genera. Van Slageren (1994) described 22 Aegilops, 1 Amblyopyrum and 4 Triticum species. Sakamura (1918), Sax and Sax (1924), and Kihara (1924) used cytogenetic methods and recognized that wheat species fall into three groups based upon their ploidy level (1) diploid 2n ¼ 14 ¼ einkorn wheat; (2) tetraploid 4n ¼ 28 ¼ emmer wheats; and (3) hexaploid 6n ¼ 42 ¼ bread wheats (Fig. 1.51). Those cytogenetic studies led to the genome definition: A, B, C, D, G, M, N, S, T, U types are still used today in wheat/Aegilops research. These studies provided knowledge on genome structure, crossability, genome size, and phylogeny. The genome formulas are summarized in Table 1.2. For more than two decades now, the use of molecular markers has provided new information on genetic diversity of Aegilops/Triticum species, their relationships (Kellogg et al. 1996; Huang et al. 2002; Provan et al. 2004; Sallares and Brown 2004; Yamane and Kawahara 2005; Petersen et al. 2006), centers of domestication (Heun et al. 1997; Ozkan et al. 2002, 2005; Mori et al. 2003; Haudry et al. 2007; Luo et al. 2007; Kilian et al. 2007b), time frame of evolution (Huang et al. 2002; Dvorak and Akhunov 2005; T. zhukovskyi u u m m GGA A A A T. aestivum 6n u u BBA A DD domestication and breeding allopolyploidization natural variation and natural selection morphologically almost indistinguishable but not interfertile T. durum u u BBA A 4n T. dicoccon u u BBA A 4n T. timopheevii u u GGA A T. dicoccoides BBAuAu 4n T. araraticum GGAuAu 6n T. monococcum AmAm 2n T. boeoticum AbAb 2n Sitopsis section of Aegilops Ae. tauschii DD Ae. bicornis Ae. searsii Ae. longissima Ae. sharonensis Ae. speltoides SS(BB / GG) SsSs SshSsh SlSl SbSb T. urartu u u AA ? Sitopsis section progenitor SS A-genome progenitor AA ? Fig. 1.51 Overview of wheat evolution and events. One similar figure has been originally published in Kilian et al. 2007a (SI). Published with permission from Oxford University Press 34 Chalupska et al. 2008), the domestication process (Tanno and Willcox 2006; Weiss et al. 2006; Kilian et al. 2007b), and the existence of specific alleles supporting domesticated traits and alleles to be considered for crop improvement (Komatsuda et al. 2007). The connection between molecular markers and domestication geography in Triticum took root in the paper by Heun et al. (1997), who found that on the basis of amplified fragment length polymorphism (AFLP) markers, the closest wild relatives of domesticated einkorn (Triticum monococcum L., diploid) occur in a very restricted area within the Karacadag mountain range in South-East Turkey. From that, they concluded, not unreasonably, that this area is the site where humans first domesticated einkorn. Importantly and uniquely among the cereals, hexaploid bread wheat (Triticum aestivum L.) has no direct hexaploid wild progenitor (Fig. 1.51). It possesses three sets of homoeologous chromosomes, designated as BBAuAuDD (first position of B chromosomes indicate that the cytoplasm was provided by the B-genome donor), whose origins have differing degrees of certainty. The superscript “u” in the Au-genome designation indicates that the A-genome is of the type found in Triticum urartu Thum. ex Gandil. The D chromosomes stem from wild diploid Aegilops tauschii through alloploidization with the domesticated tetraploid T. dicoccon Schrank (emmer, BBAuAu) that was domesticated from wild T. dicoccoides (Körn. ex Aschers. & Graebn.) Schweinf.; (wild emmer wheat, BBAuAu). See also Kihara (1944), McFadden and Sears (1944, 1946) or Huang et al. (2002) for more details. The Au and B chromosomes derive from the hybridization between the wild AuAu diploid T. urartu and a wild diploid B-genome donor (Dvorak 1976; Nishikawa 1983; Dvorak et al. 1988, 1993; Huang et al. 2002; Kilian et al. 2007a), frequently reported to belong to the Sitopsis section of Aegilops, which includes five species. Strong evidence points to the outcrossing Aegilops speltoides (SS) (or an unknown similar species) as the female parent of all wild tetraploid wheats (Sarkar and Stebbins 1956; Riley et al. 1958; Tsunewaki and Ogihara1983; Dvorak and Zhang 1990; Wang et al. 1997; Khlestkina and Salina 2001; Petersen et al. 2006; Kilian et al. 2007a; Chalupska et al. 2008) and to T. urartu (AuAu) as the male parent (Dvorak and Zhang 1990; Huang et al. 2002; Zhang et al. 2002; Kilian et al. 2007a). Kilian et al. (2007a) used a 4-tiered approach. B. Kilian et al. Using 70 AFLP loci, they sampled molecular diversity among 480 wheat lines from their natural habitats encompassing all S-genome Aegilops (Sitopsis section), to learn which are the putative donors of wheat B-genome and the G-genome of the second wild tetraploid wheat species T. araraticum Jakubz. (Araratian wheat, GGAuAu) and the hexaploid domesticated wheat T. zhukovskyi Menabde et Ericzjan (Zhukovskyi’s wheat, GGAmAmAuAu). Fifty-nine Aegilops representatives for S-genome diversity were compared at 375 AFLP loci with diploid, tetraploid, and 11 nulli-tetrasomic T. aestivum cv. Chinese Spring lines produced by Sears (1954). B-genome-specific markers allowed pinning the origin of the B-genome to S chromosomes of Ae. speltoides, while excluding other Aegilops section Sitopsis species. The outbreeding nature of Ae. speltoides influences its molecular diversity and bears upon inferences of B and G-genome origins. Haplotypes at nuclear and chloroplast loci ACC1, G6PDH, GPT, PGK1, Q, VRN1, and ndhF for ~70 Aegilops and Triticum lines (0.73 Mb sequenced) reveal both B- and G-genomes of polyploid wheats as unique samples of Ae. speltoides haplotype diversity. These have been sequestered by the T. dicoccoides and T. araraticum [wild progenitor of T. timopheevii (Zhuk.) Zhuk. Timopheev’s wheat, GGAuAu] lineages during their independent origins. The hybridization, which generated the BBAuAu wheats, may have taken place between 0.25 and 1.3 MYA according to some estimates (Mori et al. 1995; Huang et al. 2002; Dvorak and Akhunov 2005), while the event that led to the GGAuAu wheats likely occurred later (Huang et al. 2002). The distinctly reticulate evolutionary relationships between wheats, with different ploidy levels tracing to hybridization events, are shown in Fig. 1.51. However, despite intensive research, the origin of the B-genome of wheat still remains in great obscure (Huang et al. 2002; Yamane and Kawahara 2005; Petersen et al. 2006). Of all other genomes analyzed, the Ae. speltoides genome is the most closely related to the wheat B-genome. Yet, molecular studies, as well as genome size analysis (Eilam et al. 2007), suggest that Ae. speltoides in its present form could serve as the donor of the wheat B-genome. The most common opinion is that B-genome was donated by another related species, yet not found, or extinct, or that the B-genome of wheat is a recombinant genome that combines the genetic contribution of several 1 Aegilops diploid species (Zohary and Feldman 1962; Johnson 1975; Feldman 1978). Also, the recent study of Salse et al. (2008) on the evolutionary relationships at the Storage Protein Activator (SPA) locus region could not gain more conclusions. Four bacterial artificial chromosome (BAC) clones, spanning the SPA locus of, respectively, the A-, B-, D-, and S-genomes, were isolated, sequenced, and compared. On the basis of conserved sequence length as well as identity of the shared nontransposable element regions and the SPA coding sequence, Ae. speltoides appears to be more evolutionary related to the B-genome of T. aestivum than the A- and D-genomes. However, the differential insertions of transposable elements (TE), none of which are conserved between the two genomes, led to the conclusion that the S-genome of Ae. speltoides has diverged very early from the progenitor of the B-genome, which remains to be identified. It is accepted that T. aestivum originated from a cross (crosses) between domesticated hulled tetraploid emmer T. dicoccon (or the free-threshing hard wheat T. durum, or the free-threshing archeological T. parvicoccum Kislev) and the goat grass Aegilops tauschii (DD) (Kihara 1944; McFadden and Sears 1946; Kerber 1964; Kislev 1980; Dvorak et al. 1998a, b; Matsuoka and Nasuda 2004). This cross should have taken place after emmer (or hard wheat cultivation) spread east from the Fertile Crescent into the natural distribution area of Ae. tauschii. The cross occurred most probably south or west of the Caspian Sea about 8,000 years ago (Hammer 1980b; Nesbitt and Samuel 1996; Salamini et al. 2002; Giles and Brown 2006). Aegilops tauschii encompasses several morphological varieties that are roughly grouped into Ae. tauschii ssp. tauschii and Ae. tauschii ssp. strangulata (Kihara et al. 1965; Hammer 1978; Jaaska 1995; Dvorak et al. 1998a). Several studies show that Ae. tauschii ssp. strangulata provided the wheat D-genome (at least twice), but contributions from both subspecies are also discussed (Nishikawa et al. 1980; Jaaska 1981; Dvorak et al. 1998b; Talbert et al. 1998). If only a few Ae. tauschii genotypes participated in the synthesis of T. aestivum, this polyploidization should have been accompanied by the reduction of wheat diversity (Haudry et al. 2007). However, high mutation rates, together with buffering effects caused by polyploidy, enabled hexaploid wheat to enhance their diversity (Dubcovsky and Dvorak 2007). 35 1.3.1 Distribution of the S-Genome Species of Aegilops The geographical distribution of all Aegilops Section Sitopsis species is of interest as they may have contributed to the B-genome of wheat. All five species are diploids and mostly have limited distribution (Table 1.2; Figs. 1.3–1.14). Ae. bicornis, Ae. longissima, Ae. sharonensis, and Ae. searsii all occur within a very limited area in the Near East. Only Ae. speltoides can be found along the Fertile Crescent with both races often occurring sympatrically and without ecological tendencies (Hammer 1980a). The question of tetraploid wheat evolution now arises. Where did wild emmer (T. dicoccoides, genome-BBAuAu) and wild T. araraticum (genome-GGAuAu) originate? Which Sitopsis species donated genomes-B and G to wheat? If Ae. speltoides was the donor of the wheat B-genome (especially the ssp. ligustica; Sarkar and Stebbins 1956), then this may have happened over a large area, comprising almost the entire Fertile Crescent and large parts of Turkey. If, on the other hand, any of the other Sitopsis species was involved, the most likely region must have been the Jordan River valley. 1.3.2 Phylogenetic Relationships within and between Aegilops–Triticum Wheat genome donors are of great interest, and efforts to study their genomes have been undertaken and are currently underway. Research focuses mainly on Aegilops section Sitopsis species as the potential wheat Bgenome donors; on Ae. tauschii as the wheat D-genome donor; and on Triticum urartu as the A-genome donor. Studies on phylogenetic relationships within and between Aegilops–Triticum have been based on various methods (Table 1.4). Recent molecular studies, however, still suffer from limited and biased taxon sampling. Rarely, all diploid species of Aegilops and Triticum are included in such comparative analyses. For instance, no one has considered all 23 Aegilops and all the four wild Triticum (diploid: T. urartu, T. boeoticum Boiss.; tetraploid: T. dicoccoides and T. araraticum) species. The most complete molecular studies in terms of taxon sampling, suitable outgroups, and loci considered 36 have been published by Yamane and Kawahara (2005) and by Petersen et al. (2006). These authors, in addition, summarize the recent literature on the subject. Petersen et al. (2006) resequenced two nuclear single-copy genes (disrupted meiotic cDNA, DMC1; and translation elongation factor G, EF-G) and the chloroplast locus ndhF. The authors found strong evidence that the wheat D-genome was derived from Ae. tauschii, the wheat A-genome was derived from T. urartu, and the wheat B-genome was derived from Ae. speltoides. Their phylogenetic analysis suggests that Triticum, Aegilops, or Triticum plus Aegilops are not monophyletic. Ae. speltoides clusters with all other wheat B-genomes at a basal position of the tree and therefore violates the monophyly of the Aegilops– Triticum group. They also discussed the option that monophyly could be restored by the exclusion of Ae. speltoides. In this case, Ae. speltoides should be removed from Aegilops and transferred to the genus Sitopsis (Jaub. & Spach) Löve. Yamane and Kawahara (2005) studied the intraand interspecific relationships among diploid Aegilops– Triticum species. Their analysis focused on four noncoding chloroplast genome regions (trnC–rpoB intergenic region, the trnF–ndhJ intergenic region, the ndhF–rpl32 intergenic region, and the atpI–atpH intergenic region). The authors concatenated the sequence data for each accession (2,740 bp without indels, microsatellites, and inversions), studied DNA sequence variation, and detected 62 haplotypes in 115 accessions of 13 diploid species. Yamane and Kawahara (2005) found evidence that Aegilops and Triticum species should be included in one genus only; if Aegilops and Triticum are retained as separate genera, then Ae. speltoides must be placed in a new genus. Several accessions of each species were analyzed. This allowed them to conclude that several Aegilops species including the Sitopsis section of Aegilops (except Ae. speltoides) underwent speciation. The authors point out that Ae. mutica does not occupy a basal position in the Aegilops–Triticum tree and may have originated relatively recently. Therefore, the authors include Ae. mutica in Aegilops. In their study, Ae. speltoides clustered at a basal position and differed significantly from other Sitopsis species. Ae. markgrafii seems to be polyphyletic and the section Comopyrum paraphyletic. B. Kilian et al. 1.3.3 Case Study: Grain Hardness – A Trait Modified by Domestication Grain hardness or texture is an important quality trait because of its connection with the susceptibility to damage during milling and the amount of water uptake during baking. Compared to T. aestivum, T. durum Desf. (hard wheat) has hard endosperm. A single locus influencing hardness (i.e., conferring the “soft” phenotype) has been named Ha (hardness) and mapped to the short arm of chromosome 5D (Sourdille et al. 1996). The locus encodes mainly friabilins, proteins included in the prolamin superfamily: puroindoline a (Pina), puroindoline b (Pinb), and grain softness protein (Gsp-1) (Gautier et al. 1994; Rahman et al. 1994; Kan et al. 2006). The three genes are tightly linked (Sourdille et al. 1996; Giroux and Morris 1998; Giroux et al. 2000; Chantret et al. 2004). The three genes have been investigated in BAC clones of several Triticum and Aegilops species (Tranquilli et al. 1999; Turnbull et al. 2003; Chantret et al. 2004, 2005; Li et al. 2008a, b). The molecular basis and the evolutionary events at this locus were considered. The variation at the Ha locus arose from gene losses after polyploidization. Genomic rearrangements, such as transposable element insertions, deletions, duplications, and inversions contributed to the differences between species of different ploidy levels (Chantret et al. 2005; Massa and Morris 2006). Pina and Pinb genes are conserved in all diploid Triticum, Aegilops, and closely related Pooideae but are deleted from the Au and B chromosomes in tetraploid BBAuAu wheats (Gautier et al. 2000; Li et al. 2008a, b). The Pina and Pinb gene losses in BBAuAu tetraploids were caused by a large genomic deletion, probably of independent origin in the Au and B progenitor genomes (Li et al. 2008a, b). Pina and Pinb genes are nevertheless present on chromosome 5D in hexaploid wheats, because they were donated by Ae. tauschii, at the time of the emergence of the allohexaploid bread wheat. Recently, Li et al. (2008a, b) have shown that Pina and Pinb were eliminated from the G-genome but maintained in the Au-genome of tetraploid GGAuAu wheats. This supports the independent polyploidization events leading to BBAuAu and GGAuAu wheats. 1 Aegilops The Gsp-1 genes are conserved in genomes Au-, B-, D-, and G- at all ploidy levels. They constitute a multigene family and may be functionally important, particularly in T. durum where they have major roles in plant defense and only a minor influence on grain texture (Gollan et al. 2007). After the acquisition of Ha by hexaploid wheats via the D-genome, the spreading of the hexaploid species to the north forced breeders to select hexaploid hard wheat cultivars, and thus the selection pressure on Ha increased. Hexaploid hard wheats have a mutation in either Pina or Pinb but not in Gsp-1 (Giroux and Morris 1998). In addition, other genetic factors unlinked to the Ha locus may contribute to modify grain hardness (Perretant et al. 2000). Massa and Morris (2006) documented the complete coding sequence for Pina, Pinb, and Gsp-1 genes in the Tribe Triticeae. Maximum likelihood analyses performed on Bayesian phylogenetic trees showed distinct evolutionary patterns among Pina, Pinb, and Gsp-1. Results revealed positive selection at Pina and detected amino acid residues along the mature Pina protein with a high probability (>95%) of having evolved as a response to better adaptation. Massa and Morris (2006) hypothesized that positive selection at the Pina region is congruent with its role as a plant defense gene. The recent knowledge on puroindolines is summarized in Morris (2002) and Bhave and Morris (2008a, b). 1.4 Cytogenetic Studies and Karyotype 1.4.1 Wheat–Aegilops Genetic Relationships by Chromosome Pairing Hybrids between wheat and different Aegilops species have been produced and documented by different researchers (Kihara 1937; Knobloch 1968; Kimber and Abu Bakar 1979; Sharma and Gill 1983; Table 1.5). Kimber and Abu Bakar (1979) developed an important database on chromosome pairing during meiosis in hybrids between wheat and its relatives. This database has been used for assessing genome affinity and determining species relationships (Kimberet al. 1981; Mujeeb-Kazi and Kimber 1985; Gill and Chen 1987). Based on chromosome pairing information, 37 numerical methods of assessing genome affinity or similarity of the A-, B-, and D-genomes of T. aestivum to related genomes of other species have been developed (Kimber and Hulse 1978; Driscoll et al. 1979; Alonso and Kimber 1981; Kimber and Alonso 1981; Kimber et al. 1981). Genomic affinity of individual chromosomes can also be determined by sequential banding and genomic in situ hybridization (GISH) (Jiang and Gill 1993, 1994). Staining techniques were used to develop a cytogenetic karyotype of wheat and to analyze cereal chromosomes (Gill and Kimber 1974; Gill et al. 1991b). Nonisotopic methods of mapping DNA sequences in situ on chromosomes were used to construct a molecular karyotype of wheat (Rayburn and Gill 1985; Jiang and Gill 1994). These methods had greatly facilitated cytogenetic analysis in wheat and related species; and vertical transfers of chromosomes or of their segments among or within species (Friebe et al. 1991, 1996a, b). Data obtained from these different approaches allowed the description and a better understanding of the relationships between Aegilops and wheat genomes. 1.4.2 Genome Size in Aegilops–Triticum Genome size is a constant feature of a species of any organism. However, a number of evolutionary processes affect genome size, including polyploidization, fixation of accessory chromosomes, formation of large duplications, and expansions of satellite DNA, or the dynamics of transposable elements (SanMiguel et al. 1998). Recently, Eilam et al. (2007, 2008) determined genome size in Aegilops species (Table 1.2). In these diploid species, using flow cytometry, they detected a very reduced intraspecific variation. However, in contrast to the situation found at the intraspecific level, at the interspecific level, they report that the DNA amount per haploid nucleus ranges from 9.59 pg in Ae. cylindrica to 12.64 pg in Ae. kotschyi. Allotetraploid species with either the S-, G-, or B-genome, namely Ae. kotschyi and Ae. peregrina, have the largest amount of DNA, and those with the C-genome, that is, Ae. cylindrica and Ae. triuncialis, have the smallest. According to the cited authors, the difference between the intraspecific and the interspecific values should reflect interspecific changes in DNA amount that occurred during speciation. Aegilops cylindrica Aegilops geniculata Aegilops juvenalis Aegilops kotschyi Aegilops longissima Aegilops markgrafii Aegilops mutica Aegilops neglecta Aegilops peregrina Aegilops searsii Aegilops sharonensis Aegilops speltoides Aegilops tauschii Aegilops triuncialis Aegilops umbellulata Aegilops uniaristata Aegilops vavilovii Aegilops ventricosa Triticum aestivum Triticum monococcum Triticum timopheevii Triticum turgidum Triticum zhukovskyi þ þ þ þ þ þ þ þ þ þ þ þ þ nd nd nd þ þ þ þ þ þ þ þ þ þ þ þ þ þ nd nd nd þ nd nd nd nd nd nd þ þ þ þ þ nd nd nd þ þ þ þ þ þ þ nd nd nd þ þ þ nd nd nd þ nd nd nd þ þ þ þ þ nd nd nd þ þ þ þ þ þ þ nd nd nd þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd þ þ þ nd nd nd þ þ þ þ þ þ þ nd nd nd nd nd nd þ þ N þ þ þ þ þ nd nd nd þ þ þ þ þ þ nd nd nd þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ nd nd nd þ þ nd nd nd þ þ þ þ þ nd nd nd þ þ þ þ þ nd nd nd þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd Triticum zhukovskyi nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd þ þ þ U Triticum turgidum nd nd nd nd nd UC Triticum timopheevi nd nd nd nd nd D Triticum monococcum nd nd nd nd nd S Triticum aestivum þ UM/ UMN Aegilops ventricosa SS Aegilops vavilovii SU Aegilops uniaristata T Aegilops umbellulata C Aegilops triuncialis Aegilops searsii? S l, S h Aegilops neglecta Aegilops peregrina? SU Aegilops sharonensis Aegilops mutica DMU þ þ þ þ þ þ nd nd nd MU Aegilops tauschii þ CD Aegilops speltoides þ þ Aegilops markgrafii DM/DDM /DMS Aegilops longissima M Aegilops kotschyi UM Aegilops juvenalis UM Aegilops geniculata Sb Aegilops cylindrica Sb UM UM M DM/DDM /DMS CD MU DMU SU Sl C T UM/UMN SU SS Ssh S D UC U N DMS DN ABD Am GA BA GAA Aegilops crassa Aegilops bicornis Aegilops biuncialis Aegilops columnaris Aegilops comosa Aegilops crassa Aegilops comosa Genome Aegilops columnaris Female ♀ Aegilops biuncialis Male ♂ Aegilops bicornis Table 1.5 Available information on Aegilops interspecific hybrids (based on Kimber and Feldman 1987). + Positive results, nd Not determined DN ABD Am GA BA GAA þ þ þ þ þ þ þ nd nd nd þ þ þ þ þ þ þ þ þ þ þ þ nd nd nd þ nd nd nd þ þ þ þ þ þ þ þ þ þ nd nd nd þ nd nd nd þ þ þ nd nd nd þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ þ 1 Aegilops 1.4.3 Gene Flow Between Aegilops and Triticum Hybridization and introgression are natural processes occurring particularly among closely related species. Cultivated plants, wheats included, hybridize naturally with their wild relatives (De Candolle 1883; Ellstrand et al. 1999). Also, the natural hybridization between wheat and some of the Aegilops generates sometimes viable seeds (van Slageren 1994). It is, therefore, not surprising that gene flow from wheat to Aegilops may have negative consequences for the wild species, such as formation of a super-weed and transfer of herbicide resistance. Natural gene transfer from wild to cultivated species requires their occurrence in the same field, pollen shedding by the donor, stigma receptivity of the recipient species, and viability of the derived progenies. All wild relatives of cultivated wheat have the potential to hybridize with wheat (van Slageren 1994). These Aegilops and Triticum species are annual, predominantly self-pollinating species well adapted to the seasonal rainfall of their geographic distribution area (Calder 1966). The flowering time of Aegilops and other wheat wild relatives is from April–May until June–July, depending on the species and on the location (van Slageren 1994). This period coincides with the flowering of cultivated wheat in the Mediterranean environments (Azzi 1954). The spike of Aegilops and bread wheat require 3 to 5 days to complete flowering (Peterson 1965; Boguslavsky 1979), the duration is longer in Aegilops than in wheat, due to asynchronous tillering (van Slageren 1994). This enables wild species to better adapt to the environment and to ensure seed production. The continuous flowering period of Aegilops species increases their chance of cross pollination with cultivated wheat. In addition, the success of gene flow depends on pollination mode (Hamrick et al. 1979; Govindaraju 1988), flower structure, and pollen dispersal (Waines and Hegde 2003). Most Aegilops species are autogamous (self fertilizing) (Peterson 1965; Hammer 1980b), whereas Ae. speltoides is allogamous (cross pollinating) and Ae. markgrafii facultative allogamous (Hammer 1980a; Hammer 1987). Hybridization and gene transfer depend, in part, on the degree and duration of glumes opening at anthesis, on anther size, and on 39 pollen production and viability (Hucl 1996; Waines and Hegde 2003). The rate of outcrossing of autogamous Aegilops species is not well documented, but a large variation of traits affecting floral ecology was found in 114 races of the autogamous Aegilops tauschii (Hammer 1978). Pollen dispersal depends on anther extrusion and on the amount of pollen produced per anther (Joppa et al. 1968). Viability of pollen ranges between 15 and 30 min, depending on environmental conditions (de Vries 1971), and this time period is sufficient to allow cross-pollination (Hedge and Waines 2004). For instance, wheat pollen has the capacity to move at distances more than 60 m (Khan et al. 1973). No published information exists on pollen transport in Aegilops species. 1.4.4 Spontaneous Hybridizations Between Wild Wheat Relatives and Bread Wheat The occurrence of natural hybridizations between bread wheat and its wild relatives has been documented (Kimber and Feldman 1987; van Slageren 1994; Zaharieva and Monneveux 2006). For instance, spontaneous hybrids between Ae. geniculata and bread wheat were reported by Requien in 1825 and Fabre in 1838 (Dondlinger 1916; van Slageren 1994); natural hybrids between Ae. neglecta and bread wheat and between Ae. triuncialis and bread wheat were described by Godron (1854) and Lange (1860), respectively. The first Aegilops cylindrica wheat hybrid was described in 1917 by von Degen (van Slageren 1994). Van Slageren (1994) listed natural hybrids between bread wheat and various Aegilops species in Europe. Kimber and Feldman (1987) provided an overview on Triticum Aegilops hybrids. Guadagnolo et al. (2001a, b) reported that under field conditions in Switzerland, the hybridization rate between Ae. cylindrica and wheat was 3%. The authors described that natural hybrids were limited to tetraploid Aegilops species and wheat. The hybrids were observed along roadsides, adjacent to wheat fields, or next to the fields where wheat had been cultivated in the previous year. Most natural hybrids between Aegilops and Triticum were sterile, but seeds were occasionally produced. Snyder et al. (2000) observed that the hybrid fertility between Ae. 40 cylindrica and wheat ranged from 2 to 4% and that viable seeds can be produced by hybrids with either jointed goatgrass (Ae. cylindrica) or wheat as a pollen donor. It can be concluded that the transfer of a transgene from genetically modified wheat to Aegilops spp. could take place. The distribution patterns of wild wheat relatives indicate that ecological situations exist with a higher likelihood of interspecific hybridization and gene transfer between wheat and wild relatives. Hybrid seed set between tetraploid Aegilops and wheat shows a great variation. The highest value is found when an Aegilops species is the female parent. Moreover, hybrids sterility can be overcome by backcrossing the hybrid to a parent or by spontaneous chromosome doubling. The close relationship between the bread wheat D-genome and most of the constitutive genomes of the tetraploid Aegilops suggest a higher probability of transfer when the trait is located on a D-genome chromosome. Gene introgression from wheat is expected to occur more frequently in Ae. cylindrica and Ae. ventricosa, given the high recombination between homologous D-genome of the wheat and the Aegilops chromosomes. Attention should focus on the tetraploid species, which are more abundant and intercross more frequently with cultivated wheat. 1.5 Role in Development of Cytogenetic Stocks and Their Utility 1.5.1 Substitution and Addition Lines of Aegilops in Triticum Background Since bread wheat is an allohexaploid species with A, B, and D-genomes, each of the chromosomes has two closely related chromosomes. Therefore, most genes have homoeoalleles (one pair per genome), which can functionally compensate for one another. Because of this genetic structure, bread wheat easily tolerates addition or deletion of a pair of chromosomes, or of a single chromosome, or of part of a chromosome. It is, in this sense, well known that wheat tolerates addition of chromosomes from Aegilops or substitution of a chromosome with a homoeolog of Aegilops. Aegilops addition and substitution lines allow to study the genetic effects of individual alien chromosomes in the background of hexaploid wheat, and to understand B. Kilian et al. the homoeologous relationship between chromosomes of different species (Miller and Reader 1987), besides locating genes on a particular chromosome (Riley et al. 1966). Up to date, 18 Aegilops species have been used to produce complete or partial sets of addition lines (Table 1.6) and 11 Aegilops species to produce complete or partial set of substitution lines (Table 1.7). Aegilops addition and substitution lines are the starting materials of prebreeding programs aimed at the transfer of alien traits to cultivated varieties (Feldman and Sears 1981). Knowing the characters of Aegilops species, it is possible to identify Aegilops chromosomes or their segments based on plant morphology, chromosome banding, and biochemical and molecular markers. The first step in production of an addition line is to generate a wheat–Aegilops amphiploid. This objective is achieved by doubling the chromosomes of a wheat– Aegilops hybrid by colchicine treatment. The production method of an addition line in wheat background is presented in Fig. 1.52. In few cases, including hybrids of wheat with Ae. tauschii, Ae. comosa, Ae. longissima or Ae. kotschyi, unreduced 2n gametes were formed, resulting in spontaneous formation of amphiploids (Feldman 1983; Ozkan et al. 2001). Amphiploids are genetically stable and allow the evaluation of the alien germplasm in a common genetic background. The presence of a whole wild genome in the amphiploid hybrids renders them unsuitable for a direct agronomic use. Alien addition lines are produced by backcrossing recurrently the amphiploid to a wheat parent (Feldman and Sears 1981; Sears 1981). Progenies with the whole wheat chromosome complement and an extra chromosome are cytologically selected. These are evaluated by morphological, cytological, biochemical, and molecular markers, and a series of lines, each having a different single alien chromosome, are selected. Self-pollination of these progenies yields disomic addition lines, which are selected cytologically. In some cases, the development of addition and substitution lines can be problematic because the chromosomes of some Aegilops species carry gametocidal genes (Endo and Tsunewaki 1975; Maan 1975; Endo and Katayama 1978). Disomic addition lines are genetically stable, free of a large portion of the original alien chromatin, and allow the evaluation of the alien genes present in a single chromosome. Knowing the homoeologous group assignment of any added chromosome, it is possible to substitute it for any of its wheat homoeologs. 1 Aegilops 41 Table 1.6 List of major stocks of wheat–Aegilops chromosome addition lines Method of chromosome Telosome Chromosome disomic Aegilops identification additions (monosomic) additions species b b Ae. bicornis 3S , 7S Ae. biuncialis Five (2M,3M,7M,3U,5U) GISH, FISH Ae. comosa 2M Ae. cylindrica Two lines (one is 4C) RFLP Ae. geniculata 13 lines + 1 mono Nine + two C-band monotelo Four lines Not identified 6U Ae. longissima Two complete sets All (6SlL C-band mono) Ae. markgrafii Six lines (A missing) C-band SSR Ae. mutica Four lines (A, C, E, F) Ae. neglecta ssp. recta Ae. peregrina Three lines (homoeologous groups 5, 2, 7) 11 lines Complete set Unidentified lines Ae. searsii Complete set RFLP Complete set All seven (3S and 6S are monosomics) Ae. tauschii 3 lines (hexaploids) Ae. tauschii Complete monosomic seta in durum cv. PBW114 Ae. umbellulata Complete set (not all are pure) Ae. uniaristata Five lines, 2N not complete (6N missing) Ae. ventricosa Seven lines Shepherd and Islam (1988) Schneider et al. (2005) Riley et al. (1968) Bai et al. (1995) Friebe et al. (1999) Mettin et al. (1977) Stoilova and Spetsov (2006) Feldman (1975); Friebe et al. (1993) Friebe et al. (1992) Peil et al. (1998); Schubert and Bl€ uthner (1995) Dover (1973); Friebe et al. (1996c) Bai et al. (1994) Complete set C-band Seven lines RFLP Driscoll (1974) Yang et al. (1996) Friebe et al. (1996a); Spetsov et al. (1997) Pietro et al. (1988); Friebe et al. (1995a) Endo unpublished Miller and Reader unpublished Zhang et al. (2001) Friebe et al. (2000) C-band Dhaliwal et al. (1990) C-band, GISH Kimber (1967) Friebe et al. (1995b) Miller et al. (1997); Iqbal et al. (2000) Dosba et al. (1978); Dosba (1982) RFLP, isozyme C-band Ae. sharonensis 2Ssh Ae. speltoides Reference Nine lines RFLP, RAPD, SSR a Some added chromosomes are intertranslocated A substitution line is produced from an addition line by crossing the latter with a selected wheat line that is either monosomic, monotelosomic, or nullisomic for the chromosome to be substituted for. The selection of desired genotypes from the F2 progeny can be helped by cytological and marker analyses. Production of substitution lines in wheat is illustrated in Fig. 1.53. In most combinations, the alien chromosome compensates for the missing wheat homoeolog, and plant vigor and fertility are not harmed. Yet, alien undesirable chromatin still exists in the substitution lines, rendering them unsuitable for direct agronomic use. 1.6 Role in Crop Improvement 1.6.1 Traits Modified by Domestication Domesticated cereal crops differ from their wild relatives in several traits, some of them apparently consciously selected by humans. The most important Triticeae traits modified during domestication are the free-threshing state and brittle rachis. Additional modifications taking place during domestication and subsequent breeding concern seed size, kernel row 42 B. Kilian et al. Table 1.7 Overview on major stocks of wheat–Aegilops chromosome substitution lines Reference Chromosome disomic substitutions Telosome Method of Aegilops species substitutions identification Ae. comosa 2M(2A), 2M(2B), 2M(D) Riley et al. (1966) Ae. geniculata 5M(5D) Friebe et al. (1999); Dhaliwal and Harjit-Singh (2002) Ae. longissima Complete set C-band Friebe et al. (1993) 5S(5A), 5S(5B), 5S(5D) Isozymes Millet et al. (1988) A, C, D Netzle and Zeller (1984) Ae. markgrafii 5C(5A), 5C(5D) Muramatsu (1973); Friebe et al. (1992) Ae. peregrina Unidentified lines Spetsov et al. (1997) G (2A), G (2B), E (5B) Shepherd and Islam (1988) Ae. searsii Complete set 31 lines C-band Friebe et al. (1995a) Ae. sharonensis 4S(4A), 4S(4B), 4S(4D) Miller (1983) Ae. speltoides Complete set RFLP Friebe et al. (2000) Ae. tauschii Complete set in durum cv. Langdon Joppa and Williams (1988) Ae. umbellulata 1U, 2U, 5U, 7U for their wheat Riley et al. (1971, 1973); homoeologues 2 addition unknown chromosomes Chapman and Riley (1970); Shepherd and Islam (1988); Makino (1976, 1981) Ae. uniaristata 3N(3A), 3N(3B), 3N(3D) Miller et al. (1995) Fig. 1.53 Schematic overview on production of 1S1 (1B) Aegilops longissima disomic substitution lines Fig. 1.52 Schematic overview on production of Aegilops longissima disomic addition lines type, plant height, grain hardness, tillering, seed dormancy, photoperiod, vernalization, and heading date. In addition, the spread of the domesticated cereals out of the Fertile Crescent required the adaptation to new environments, supported by newly arisen favorable alleles at critical genetic loci. Studies on traits modified by domestication also provide data for phylogenetic relationships. Recent studies mainly focus on few crop model species such as rice, maize, 1 Aegilops and barley. Synteny between grass species, however, will allow collecting useful results for the much more complex wheat genome. 1.6.2 Case Study: Control of Flowering Time The control of flowering time is central to reproductive success and has a major impact on grain yield in Triticeae. Wild progenitors of domesticated cereals are well adapted to the prevailing environmental conditions in the Fertile Crescent. These species use the rainfall to establish their vegetative structures before winter, and vernalization will delay flowering until the winter has passed. In spring, soil moisture can be used for grain filling, and an early flowering in response to long days (LDs) allows the plant to complete its growing cycle ahead of the hot summer (Cockram et al. 2007). The first cereals domesticated in the Fertile Crescent most probably had the photoperiodic (response to day length) and vernalization (response to winter temperature) phenotypes of their progenitors. During the domestication process and during the spread of agriculture out of the Fertile Crescent, novel adaptive traits suited for the new environments were selected. One key event was the selection of spring types that can be also sown after winter. These spring types lack vernalization requirement and show different response to LDs. Reduced photoperiod response is important in Europe and North America, where growing seasons are long (Turner et al. 2005). Wheat, Aegilops, barley, and Arabidopsis show similar flowering responses to photoperiod and vernalization, in contrast to rice and soybean, which flower in response to short days and show no response to vernalization. We present an overview on photoperiod and vernalization research in the Triticeae. Only few studies on flowering time-related topics have been published in Aegilops, mostly focusing on Ae. tauschii and Ae. cylindrica (Shindo and Sasakuma 2001; Fandrich et al. 2008). 1.6.2.1 Photoperiod The major loci affecting the photoperiod response (Ppd genes) are in a colinear position on the short 43 arm of the group 2 chromosomes in wheat and barley. In barley, dominant Ppd-H1 alleles confer early flowering under LDs but have no effect under short days (SD). Plants carrying the mutated, recessive ppd-H1 allele are late-flowering. The Ppd-H1 is a pseudoresponse regulator (PRR) most similar to PRR7 in Arabidopsis and was positionally cloned in barley by Turner et al. (2005). These authors provided evidence that a single point mutation within the conserved CCT domain of PRR results in an amino acid change, leading to insensitivity under LDs. In wheat, the allelic series of Ppd loci has decreasing potency from Ppd-D1 to Ppd-B1 to Ppd to A1 (Worland 1996). The Ppd-H2 gene has been mapped in barley on chromosome 1H (Laurie et al. 1995). The winter allele delays flowering under short days. No equivalent gene has been identified in wheat yet. Further, major photoperiod-related genes/gene families appear to be conserved between barley and Arabidopsis, involving the GIGANTEA (GI), CONSTANS (CO), and FLOWERING LOCUS T (FT) genes in Arabidopsis and their orthologs in barley HvGI, HvCO, and HvFT (Griffiths et al. 2003; Dunford et al. 2005; Cockram et al. 2007; Faure et al. 2007). None of the grass quantitative trait loci (QTLs) associated with flowering time cosegregate with orthologous Arabidopsis “flowering” genes, that is, different major determinants of photoperiod most probably have been selected in the Triticeae (Börner et al. 1998; reviewed in Griffiths et al. 2003). At the moment, Ppd-H1 is the only locus conferring natural genetic variation in photoperiod response in barley. Jones et al. (2008) studied molecular diversity at the Ppd-H1 locus in a comprehensive barley collection. The mutated nonresponsive, late-flowering allele ppd-H1 was present in wild barley from Iran, suggesting that the nonresponsive mutation originated in wild barley in the eastern part of the Fertile Crescent. Evidence is still missing on the botanical status of these wild accessions. These wild barleys could have received introgressions from cultivated barleys. Recently, Matsuoka et al. (2008) studied the timing of flowering in 200 lines of Ae. tauschii. Such studies on the ecological and geographical framework are needed for our understanding of wild wheats and their hidden potential for wheat improvement. 44 1.6.2.2 Vernalization In the Triticeae, two major genes, with epistatic interactions, control the vernalization (VRN) pathway: VRN1 and VRN2 (Yan et al. 2003, 2004a, b; von Zitzewitz et al. 2005; Dubcovsky et al. 2006). The VRN1 gene on chromosome 5 in wheat and barley is similar to the Arabidopsis MADS-box transcription factor Apetala 1 (AP1), which initiates the transition of the apical meristem from the vegetative to the reproductive state (Yan et al. 2003). Most probably the same gene should map in a paralogous location also in species of the genus Aegilops. Mutations in regulatory regions (promoter and the first intron of this gene) are associated with a dominant spring growth habit (Vrn1) (Yan et al. 2003, 2004a; Fu et al. 2005; von Zitzewitz et al. 2005). The second vernalization gene, VRN2 (ZCCT in barley), is a zinc finger CCT domain transcription factor that blocks the photoperiod pathway through direct or indirect downregulation of VRN1 and VRN3 (Fu et al. 2005; Karsai et al. 2005; Koti et al. 2006). VRN2 transcription is repressed by vernalization and by short days. Lossof-function mutations (vrn2a), or complete gene deletion (vrn2b), are associated with a recessive spring habit that does not require vernalization to flower (Yan et al. 2004b; Dubcovsky et al. 2005). It was recently shown that a third vernalization locus in barley is located on chromosome 7H, VRNH3, colinear with VRN-B3 in bread wheat and encoding an ortholog of the Arabidopsis floral pathway integrator, FT1, and colinear with OsFT of rice (Yan et al. 2006; Faure et al. 2007). The dominant, earlyflowering wheat Vrn3 allele is associated with the insertion of a retroelement in the promoter, while in barley, a mutation in the first intron is associated with the early allele (Yan et al. 2006). This study provides evidence that differences in flowering time are associated with FT1 allelic variation. The link between photoperiod and vernalization is evident, even at the molecular level, if one considers that VRN2 is expressed only when photoperiod-responsive plants are grown under long-day photoperiod (Trevaskis et al. 2006). There is probably a second VRN1 repressor, and a candidate may be VRT2 (vegetative to reproductive transition-1), a MADS-box gene (Danyluk ucs et al. 2006, 2007). et al. 2003; Kane et al. 2005; Sz€ No molecular studies on vernalization have been carried out in wheat relatives, yet. However, Kilian B. Kilian et al. et al. (2007a, b) included one VRN1 gene fragment in their phylogenetic (multilocus) analysis of einkorn wild and domesticated lines. 1.7 Role in Crop Improvement Through Traditional and Advanced Tools Of all genera of the Triticeae tribe, Aegilops is the most closely related to Triticum. Moreover, a whole Ae. tauschii genome is a part of the bread wheat genome. Cultivated wheat suffers from inadequate genetic diversity within its primary gene pool because modern plant breeding has strengthened the tendency to reduce variability (Hammer and Laghetti 2005; Fu and Somers 2009). This situation is even more critical when undefeated resistance genes are necessary to control a newly emerged pest that threatens global wheat production (this was the case of leaf rust resistance from Ae. umbellulata (Sears 1956) and of resistance to the stem rust highly virulent race Ug99 (Singh et al. 2006)). Aegilops, on the other hand, exhibits wide diversity for various desirable attributes and, as such, serves as invaluable genetic reservoir for wheat improvement. It is, therefore, unsurprising that many attempts have been made to assess the breeding potential of different Aegilops species and to exploit them to improve genetically wheat production. In the following paragraphs, we evaluate Aegilops species as members of the gene pool available for wheat improvement. Hybrids between hexaploid wheat and, for example, Ae. tauschii have seven bivalents at the meiotic first metaphase. This indicates that each chromosome of Ae. tauschii is homologous to its respective chromosome of the wheat D-genome and readily pair with it at meiosis. Indeed, Ae. tauschii is considered by Harlan (1992) as a member of the primary gene pool of wheat. Gene transfer from D-genome of Aegilops species is straightforward and requires standard breeding methods as described below. Each one of the three wheat genomes, A-, B-, and D-, is homoeologous to the diploid genomes of Aegilops other than Ae. tauschii, namely genomes C-, M-, N-, S-, U-, and T-. The chromosomes of these genomes will only rarely pair and recombine with wheat chromosomes at meiosis. According to Harlan (1992), Aegilops species with genomes other than D are 1 Aegilops included in the secondary gene pool of wheat, and gene transfer from these species into wheat requires cytogenetic manipulations to enhance the recombination between alien and wheat homoeologous chromosomes. The polyploid nature of wheat allows it to tolerate addition of Aegilops chromosomes or substitution (see above) of its native chromosomes for their Aegilops homoeologs without a major effect on plant vigor or fertility. By the use of such addition and substitution lines, the identification of desirable genes and their transfer to wheat cultivars are facilitated. Different genetic wheat stocks with a duplicated chromosome or deficient for a chromosome have been prepared and used in the process of gene transfer. Genetic resources of Aegilops in genebanks have been systematically evaluated for useful traits (e.g., Hammer 1985; Valkoun et al. 1985). Aegilops species have been used as forage plants (van Slageren 1994) and introduced into other countries. Taxa of other genera have been used to create hybrid species. (I) Aegilotriticum Fourn. (hybrid between Aegilops species and Triticum species) is a hybrid genus with potential value for breeding purposes; (II) Aegilops also participated in the important hybrid genus Triticosecale Wittmack. (‘Triticale’, hybrid between Triticum and Secale) and (III) in the prospective Tritordeum Asch. et Graebn. (hybrid between Triticum and Hordeum). 1.7.1 Methods of Gene Transfer The ultimate goal in gene transfer is the introgression of a small alien chromosome segment carrying the desired gene without its flanking genes, which may be deleterious for wheat performance. This goal can be achieved when a gene is transferred from the Dgenome of an Aegilops species, as detailed below. However, in the case of gene introgression from Aegilops species with genomes homoeologous to the wheat genomes, the low level of homoeologous pairing results in transfer of a chromosome segment, which is long enough to carry undesired alien genes in addition to the target gene (Feldman 1988), a phenomenon called genetic drag. Different cytogenetic manipulations were proposed to reduce the amount of the alien chromatin. 45 1.7.1.1 Gene Transfer from Aegilops Species with D-Genome When the desired gene resides in the D-genome of Ae. tauschii, or of another polyploid Aegilops from section Vertebrata or of Ae. cylindrica, homologous pairing is expected between the donor and the recipient bread wheat chromosome (of the D-genome) and no pairing induction is required. Yet, as a result of ploidy difference and nonhomology between the A and B wheat genomes and the Aegilops genomes other than D, such wheat–Aegilops hybrids have a high level of sterility. One method that facilitates gene transfer from Ae. tauschii to bread wheat and also overcomes the difficulty due to ploidy difference includes the production of a synthetic allopolyploid wheat line prior to gene transfer. In this case, tetraploid wheat with BAgenome is hybridized with Ae. tauschii, and the chromosomes of the F1 hybrid are doubled using colchicine treatment. The product is a fertile synthetic hexaploid BAD genotype fully homologous to bread wheat. Hexaploid wheat homologous chromosomes will readily recombine in the hybrid. Such synthetic lines serve as a gene pool derived from Ae. tauschii that is ready for screening for any desired trait and allow for an easy transfer of the responsible gene. Indeed, this method is suitable for gene transfer from Ae. tauschii to wheat (Table 1.8) and has been adopted by a larger number of wheat breeders (e.g., synthetic lines of CIMMYT; Trethowan et al. 2003). When the gene donor is a polyploid species (e.g., Ae. ventricosa; genome-DN), a tetraploid wheat genotype (genome-BBAuAu) can be used to bridge between the donor and the recipient hexaploid wheat (Table 1.8). The initial hybrid with the BBAuAuDDNN-genome, when hybridized to bread wheat (BBAuAuDD), generates fertile derivatives where only chromosomes of the N-genome remain unpaired. In such hybrids, translocations may occur mainly between chromosomes of the D-genomes (Delibes et al. 1987). In addition, desired alien translocations can be obtained also between N chromosomes and other wheat chromosomes (Jahier et al. 2001). Attempts to directly hybridize Ae. ventricosa and bread wheat were unsuccessful, and the only hybrid obtained was male sterile (Doussinault et al. 1983). 46 B. Kilian et al. Table 1.8 Pest and disease resistance genes transferred from Aegilops tauschii to wheat Reference Gene(s) provided Method of transfer: Production Resistance to pests and diseases of synthetic 6x line with 4x line or direct cross with 6x wheat Cereal cyst nematode Cre3 4x Eastwood et al. (1993) 4x cvs. Martin et al. (1982); Hollenhorst and Joppa Greenbug Gb3, Gb4, Gb7, (1983); Flinn et al. (2001); Weng and Lazar Gba,a Gbb,a (2002); Smith and Starkey (2003); Zhu et al. Gbc,a Gbd,a Gbx,a Gbza (2004); Weng et al. (2005); Zhu et al. (2005) Hessian fly H26 6x cv. Karl Cox and Hatchett (1994) Leaf rust Lr21 4x Tetra Canthatchb Kerber and Dyck (1969) Dyck and Kerber (1970) Lr22a 4x Tetra Canthatchb Lr32 4x Tetra Canthatchb Kerber (1987) Lr39 6x cv. Witchita Raupp et al. (2001) Lr41 6x cv. TAM107 Cox et al. (1994) Lr42 6x cv. TAM107 Cox et al. (1994) Lr43 6x cv. TAM107 Cox et al. (1994) Powdery mildew Pm2 4x durum cv. Lutz et al. (1994) Pm19 4x durum cv. Lutz et al. (1995) Root knot nematode Rkn 4x durum McIntosh et al. (2008) Russian wheat aphid Dn3 4x T. turgidum Nkongolo et al. (1991) Septoria nodorum Snb3 4x McIntosh et al. (2008) Septoria tritici Stb5 4x T. dicoccoides Arraiano et al. (2001) Stripe rust Yr28 4x durum cv. Altar84 McIntosh (1988); Singh et al. (2000) Kerber and Dyck (1979) Stem rust Sr33 4x Tetra Canthatchb Sr45 McIntosh (1981) a Allelic or linked to Gb3 Extracted tetraploid b 1.7.1.2 Gene Transfer from Genomes of Different Aegilops Species Other than D A controlled scheme for evaluation and exploitation of Aegilops for wheat improvement was proposed by Feldman (1983) and reviewed by Qi et al. (2007). This scheme includes three steps: 1. Addition of the whole alien genome by production of a wheat–Aegilops amphiploid (see above). 2. Production of a pair of alien chromosome addition and substitution lines (see above). 3. Production of an Aegilops–wheat recombinant chromosome with the desired gene. This procedure is also known as chromosome engineering (Sears 1981). Methods to carry out this step are described below (Sect. 1.7.1.2.1–1.7.1.2.3). The procedure requires knowledge of the size and location of the transferred segment. If the introgressed segment is too long, or a genetic drag is manifested, the genetic material cannot be used directly in wheat breeding programs and requires prebreeding to delete undesired alien chromatin. A method to reduce the size of an alien segment was proposed by Sears (1981, 1983) and requires identification of the transferred segments and hybridization between transfers with recombination points at either sides of the target gene. Pairing of two translocated chromosomes, one recombined distally to the gene and the other proximally to it, will result in an interstitial alien segment. Further reduction in the size of the alien segment may be obtained by additional induction of homoeologous pairing (see Sect. 1.7.1.2.1) (Sears 1981, 1983). Ceoloni et al. (2005) combined these methods and used cytogenetic and molecular tools in their attempts to reduce the size of Agropyron elongatum (Host) P. Beauv. chromosomal segment transferred to durum wheat. While stepping forward, a smaller proportion of the alien genetic material is included in the progenies. Evaluation is carried out at every step in order to assess the potential of alien gene introgression into the wheat genetic background. This scheme is, however, time- and labor-consuming. Therefore, attempts invested in the production of translocations by homoeologous pairing would better pay back if the translocations are evaluated for additional desirable traits. 1 Aegilops Indeed in a number of cases, the initial material that was made available was used by other scientists to exploit the initiative. An example is the series of 70 Ae. ventricosa translocation lines prepared by M.A. Peña in Cuenca, Spain (Delibes et al. 1993), and used by different cytologists to select seven different gene transfers (Table 1.9). Other laboratories started their gene transfer from alien addition (Ceoloni et al. 1988) or substitution lines (Aghaee-Sarbarzeh et al. 2002; Kuraparthy et al. 2007a) that were prepared by others. In several cases, spontaneous rather than homoeologous pairing was exploited to obtain translocations (Table 1.9). Induction of Homoeologous Pairing The preferred method for gene transfer is chromosome pairing induction between the donor and the recipient chromosomes. Since under induction, pairing may occur among all homoeologs (including chromosomes of the wheat genomes). This step should be followed by a series of backcrosses to the wheat parent in order to recover the original wheat genomes and accompanied with selection for the desired Aegilops segment bearing the target trait. The most popular method to enhance pairing between homoeologous chromosomes is the use of the recessive mutant of the homoeologous pairing suppressor Ph1, located on the long arm of chromosome 5B (Okamoto 1957; Riley and Chapman 1958). The mutant ph1b corresponds to a deficiency of the Ph1 locus of common wheat (Sears 1977) and the mutant ph1c of Ph1 in durum wheat (Giorgi 1983). Another homoeologous pairing suppressor, termed Ph2, with much weaker expression, has been located on 3DS of wheat (Mello-Sampayo and Canas 1973), but it was rarely used to enhance pairing, except by Ceoloni and Donini (1993). In the absence of Ph1, the rate of chromosome pairing in hybrids between wheat and any Aegilops species with homoeologous genome is greatly enhanced (Riley 1966). A second method to promote homoeologous pairing is based on genes of Ae. speltoides. In this species, most lines enhance homoeologous pairing with wheat chromosomes by suppressing the action of the Ph1 gene due to the presence of the Ph1 suppressor genes Su1-Ph1 and Su2-Ph1 (Kimber and Athwal 1972; Dvorak et al. 47 2006). These lines (termed high pairing type) can be directly used to pollinate a desired wheat cultivar for gene transfer and the hybrid backcrossed to the recurrent cultivar. Early generations (F1 and BC1) are highly sterile but will produce some seeds when pollinated by the wheat cultivar parent (Feldman and Millet unpublished). Moreover, high pairing Ae. speltoides can be used as additional player in a cross of wheat with another alien species to promote pairing and recombination between chromosomes of the two alien species, and wheat homoeologs, as in Riley et al. (1968), for Ae. comosa (genome-M) and wheat. In addition, certain lines of Ae. longissima can partially suppress the Ph1 gene effect, thereby inducing homoeologous pairing (Mello-Sampayo 1971). Genotypes were found also in Ae. peregrina and Ae. kotschyi that promote homoeologous pairing (Fernandez-Calvin and Orellana 1991). Few years ago, Ph suppressor genes (Su-Ph1, are termed also PhI) were transferred from Ae. speltoides to a bread wheat line (Chen et al. 1994). This line is an efficient inducer of homoeologous pairing since PhI genes are dominant and epistatic to the wheat Ph; thus the PhI gene acts in the hybrids also as heterozygote. This method has been successfully exercised to transfer leaf rust and stripe rust resistance genes from Ae. umbellulata (Chhuneja et al. 2008a) and from Ae. triuncialis and Ae. geniculata to bread wheat (Aghaee-Sarbarzeh et al. 2002). Recovering the original wheat genome is usually obtained through a series of backcrosses of the wheat– Aegilops hybrid to a wheat cultivar as a recurrent parent. Since alien and wheat chromosomes do not pair in the presence of the Ph wild type allele, alien chromosomes and chromosome segments will be eliminated in few backcross generations. Maintenance of the desired gene requires an easy identification of the gene product (resistance, protein, etc.) or a marker adjacent to the gene to be selected for. Induction of Alien Translocations by Ionizing Irradiation One drawback associated with pairing induction between the donor and the recipient chromosomes is the reduced number of chiasmata (1–2) per pair of chromosomes and the predominant occurrence of chiasmata in the terminal and subterminal chromosome 48 B. Kilian et al. Table 1.9 Methods used in different disease- and pest-resistance gene transfers from Aegilops species other than Ae. tauschii to wheat Gene(s) transferreda Method of gene transfer Induction of Alien addition/ translocation substitution Bridging species Ae. comosa Sr34b; Yr8b PhI in Ae. speltoides T. aestivum Riley et al. (1968); McIntosh et al. (1982) Ae. geniculata Lr57; Yr40 T. aestivum Ae. longissima Pm13c Aghaee-Sarbarzeh et al. (2002); Dhaliwal and Harjit-Singh (2002); Chhuneja et al. (2007); Kuraparthy et al. (2007a) Ceoloni et al. (1988); Donini et al. (1995); Cenci et al. (1999) Donor species Resistant monosomic addition 2M PhI in Chinese Spring Disomic substitution 5Mg(5D) ph1b induced Ditelosomic 3SlS homoeologous addition line pairing Ae. peregrina Rkn-mn1 Ae. sharonensis Lr56, Yr38 Spontaneuos PhI in Ae. speltoides Ae. speltoides Lr28c Lr35b Sr39b Lr36b; Lr51 None None Pm12/Pm32 Lr47 Gb5b Sr32b Ae. triuncialis Lrtr; Lr58 Cre7; H30 Ae. umbellulata Lr9c Ae. ventricosa Ae. ventricosa a none Initial large translocation obtained by fast neutron irradiation was reduced using ph1b ph1b induced homoeologous pairing PhI in Chinese Spring Disomic substitution 5Ut(5A) Spontaneous None Yr , Lr Lr, Sr Cre5c; Pmc Resistant monosomic addition, then monosomic isochromosome addition PhI in Chinese Spring none Spontaneous none Spontaneous none Pch1c Spontaneous Lr37,c Sr38,c Yr17c; H27 Cre2; Cre6 X-ray irradiation None Reference Yu et al. (1990); Barloy et al. (2000) Marais et al. (2006) McIntosh et al. (1982) T. monococcum Kerber and Dyck (1990) Dvorak (1977); Dvorak and Knott (1990); Naik et al. (1998); Seyfarth et al. (1999); Helguera et al. (2005) Dvorak (1977); Miller et al. (1987); Dvorak and Knott (1990); Jia (1996); Hsam et al. (2003); Song et al. (2007) Wells et al. (1982) Lukaszewski (1995); Dubcovsky et al. (1998) McIntosh (1991); Friebe et al. (1996b) T. aestivum Aghaee-Sarbarzeh et al. (2002); Kuraparthy et al. (2007b) T. turgidum Romero et al. (1998); Martin-Sanchez et al. (2003); Montes et al. (2008) Sears (1956) T. turgidum T. turgidum T. turgidum T. durum T. durum T. turgidum T. turgidum Chhuneja et al. (2007, 2008a) Özgen et al. (2004) Delibes et al. (1987); Jahier et al. (1996); Jahier et al. (2001) Garcia-Olmedo et al. (1984); Jahier et al. (1978); Doussinault et al. (1983) Bariana and Mcintosh (1993, 1994); Delibes et al. (1997); Seah et al. (2001); Helguera et al. (2003); Blaszczyk et al. (2004) Delibes et al. (1993, 1997); Ogbonnaya et al. (2001) Resistance gene symbols: Yr Stripe rust, Sr Stem rust, Lr Leaf rust, Pch Eyespot, Pm Powdery mildew, Gb Green bug, Cre Cereal cyst nematode, Rkn Root knot nematode, H Hessian fly b Not used in agriculture (no information for unmarked genes) c Used in agriculture 1 Aegilops regions. Genes located in the more proximal regions of the chromosomes will not be included in the translocated segment or will be transferred together with a large alien chromosome segment. To overcome this drawback, X-ray or gamma ionizing irradiation treatments may be used to break chromosomes with the target to obtain alien chromatin transfer between the donor and the recipient genomes (Sears and Gustafson 1993). Alien and wheat chromosome segments reunite spontaneously to form alien segments embedded within the wheat chromosomes. This method was used by Sears (1956) to transfer leaf rust resistance from Ae. umbellulata (U-genome) to wheat. Irradiation results in random chromatin translocation between chromosomes. Irradiation of a genotype monosomic for both the Aegilops chromosome and one of its wheat homoeologs increases the probability for pollen selection against noncompensating translocations (Sears and Gustafson 1993). Irradiation of alien wheat hybrids in the absence of Ph1 may increase the number of compensating translocations (Sears and Gustafson 1993). A method to reduce a whole arm translocation into small segments was presented by Chen et al. (2008) in support of wheat – Dasypyrum villosum (L.) Candargy, syn. Haynaldia villosa (L.) Schur introgressions. A 6VS/6AL translocation line was gamma-irradiated and immediately pollinated by wheat, giving rise to an impressive number of small terminal and interstitial alien translocations. Gametocidal Induction of Alien Translocations Another method to induce transfer of small alien segments to wheat is based on the capacity of gametocidal genes (Sect. 1.7.2) to break chromosomes. This method proved effective in producing wheat–rye translocations but has never been used to induce wheat–Aegilops translocations. Chromosome 3C of Ae. triuncialis was introduced into wheat along with the chromosome 1R of rye (Masoudi-Nejad et al. 2002). Many small segments of 1R were translocated to different wheat chromosomes as a result of chromosome breakage caused by the gametocidal gene located on 3C. 49 1.7.2 Obstacles for Successful Gene Transfer from Aegilops Species to Wheat Exploitation of alien species for wheat improvement is hampered by several biological and genetic obstacles, such as reduced crossability between parental lines (Claesson et al. 1990; Koba and Shimada 1993) and low seed setting in the hybrid (Claesson et al. 1990). Shriveled F1 endosperms would require the usage of embryo rescue techniques (Miller et al. 1987). Wheat–Aegilops hybrids may suffer from abnormal morphology, such as lethal or semilethal necrosis, as was found by Nishikawa (1962) in hybrids between certain tetraploid wheat lines and synthetic hexaploid wheat. A different obstacle to gene transfer from Aegilops to wheat is represented by gametocidal genes (Gc) (Tsujimoto 2005), a group of selfish genes that induce chromosome breakage in gametes not having them. This mechanism prevents the transmission of these gametes and ensures that only gametes containing the Gc genes are transmitted. Consequently, the Gc-carrying Aegilops chromosome is included in the genome of every offspring deriving from self-pollinating or backcrossing of the wheat–Aegilops hybrid. Gc genes were detected on chromosome 3C of certain lines of Ae. markgrafii, and Ae. triuncialis (Endo and Tsunewaki 1975), on chromosome 2C of Ae cylindrica (Endo 1979), on chromosome 4M of Ae. geniculata (Kynast et al. 2000), on chromosomes 2Sl and 4Sl of Ae. longissima, on 2Ssh and 4Ssh of Ae. sharonensis (Maan 1975; Endo 1985), and on 2S and 6S of Ae. speltoides (Tsujimoto and Tsunewaki 1984, 1988; Kota and Dvorak 1988). Selection for a genotype lacking Gc is proposed to ensure successful gene transfer from any of the named species. An “antigametocidal” mutant wheat line that suppresses the action of Ae. sharonensis Gc2 gene was generated by Friebe et al. (2003). This line has a translocated 4BL.4BS-4SshS chromosome (4B with a terminal 4SshS segment) carrying a Gc2 gene that was mutated by EMS and is designated Gc2mut. Normal transmission of mutant and wild type alleles was observed in heterozygotes Gc2/Gc2mut rather than preferential transmission of Gc2. This mutant, which allows for exclusion of the undesired 4Ssh chromosome from 50 wheat lines having introgression from Ae. sharonensis, was used by Millet et al. (2007) in their attempt to introgress leaf rust and stripe rust resistance from Ae. sharonensis to wheat. 1.7.3 Exploitation of the Aegilops Gene Pool for Wheat Improvement Conspicuous diversity in a wide variety of attributes is found in different Aegilops species (Table 1.10). These attributes include resistance to biotic stresses (different diseases and pests; Tables 1.8–1.10), tolerance to abiotic stresses such as drought, extreme temperature, soil mineral toxicity, and deficiency, and improvement of nutritional value (protein content) and product quality (protein and starch attributes; Table 1.10). Nevertheless, as evident from Table 1.8 (D-genome introgressions) and Table 1.9 (introgressions from other genomes), the only genes that have been transferred from Aegilops to wheat are those controlling resistance to biotic stresses. This may be explained as the outcome of three main reasons: 1. The urgent need to combat diseases and other pests. Past and current resistances may be defeated by the pathogen and new resources are needed to save the crop. 2. The predominant simple inheritance (usually monogenic) of the resistance, when it is compared to more complex traits such as drought, heat, or salt tolerance, or protein composition. 3. The ease of using the resistance/susceptibility symptoms as a direct selection marker (there is no need to develop and use molecular or other markers). Moreover, even when dealing with pest resistance genes, only a small portion of the transfers were actually used in agriculture (McIntosh et al. 1995; Friebe et al. 1996b), perhaps because of the genetic drag resulting from a transfer of the long segments of Aegilops chromosomes, which negatively affect the crop (Ortelli et al. 1996). To conclude, the pioneering work of Sears (1956) is still the method of choice used to transfer genes from Aegilops to wheat. The improvement of chromosome engineering methodologies and the public objection to genetically modified organisms (GMO) indicate that chromosome engineering may remain the preferred B. Kilian et al. method in the near future. Modern molecular tools now facilitate the transfer of chromosomes and allow selecting for tiny translocations, which have an expected minimal deleterious effect on wheat performance. The underutilized gene pool of Aegilops is the best genetic resource for wheat improvement. A greater demand for useful variation in response to diverse and changing environment and in product quality should further promote the exploitation of the Aegilops gene pool. 1.7.4 More Uses of Aegilops Species 1.7.4.1 Aegilops Cytoplasms as Male Sterility Inducer in Wheat Already Kihara (1951) showed that nucleus substitution in Ae. markgrafii cytoplasm by bread wheat produces male sterile alloplasmic wheat lines. This nucleus substitution was carried out by pollinating an Ae. markgrafii genotype by a bread wheat cultivar and backcrossing by the wheat parent as a male. Usually, 4 to 7 backcrosses were sufficient to eliminate the Aegilops chromosomes (Panayotov 1980), and the process can be accelerated by cytological selection of the offspring. A long-term study showed that between 5 and 40 backcross generations, these alloplasmic wheat lines remained unchanged, that is, they are male sterile and female fertile (Tsunewaki 1993). In a review on genome–plasmon interactions, Tsunewaki (1993) clarified that the combinations of 12 wheat varieties as nucleus donors with different Aegilops cytoplasms resulted in different levels of male sterility. Similar results were obtained by Panayotov (1980) using two bread wheat cultivars with 17 Aegilops cytoplasms. Consequently, cytoplasms from Ae. biuncialis, Ae. markgrafii, Ae. columnaris, Ae. comosa, Ae. geniculata, Ae. neglecta, Ae. speltoides, and Ae. triuncialis were shown to completely male-sterilize at least one cultivar. Fertility restoration genes (Rf) against sterilizing cytoplasms were found in wheat (Tsunewaki 1982) but are naturally present in the genome of the cytoplasm donor species. Moreover, an Rf gene against the sterilizing cytoplasm of T. timopheevii was transferred from Ae. umbellulata to wheat (Yinhuai et al. 1991). A system was proposed, based on alloplasmic female lines and a restorer line, to produce hybrid 1 Aegilops 51 Table 1.10 Exploitable traits from Aegilops species (excluding traits that have been already transferred – see Tables 1.8 and 1.9) Donor species Gene(s) studied and Reference chromosome positions, the genome of bread wheat (a) Resistance to pests and diseases Barley yellow dwarf Cereal aphid Cereal cyst nematode (Heterodera avenae) Eyespot (Tapesia yallundae) Fusarium head blight Greenbug (Schizaphis graminum) Hessian fly (Mayetiola destructor) Leaf rust (Puccinia recondita) Ae. biuncialis, markgrafii, neglecta, triuncialis Ae. searsii, columnaris, neglecta, umbellulata Ae. peregrina Holubec and Havlı́čková (1994) CreX; CreY Jahier et al. (1998) Ae. ventricosa Chao et al. (1989); Huguet-Robert et al. (2001); Groenewald et al. (2003) Ae. speltoides Fedak et al. (2004) Ae. speltoides Ae. geniculata, longissima, speltoides, tauschii Ae. tauschii Ae. kotschyi Ae. markgrafii Ae. peregrina Ae. tauschii Ae. umbellulata Ae. searsii, umbellulata Powdery mildew Ae. comosa (Erysiphe Ae. geniculata graminis) Ae. sharonensis Ae. tauschii Septoria tritici Soil borne mosaic virus Spot blotch Stem rust (Puccinia graminis) Stripe rust (Puccinia striiformis) Tan Spot Makkouk et al. (1994) Ae. umbellulata Ae. longissima, searsii, umbellulata Ae. speltoides Ae. tauschii Ae. sharonensis Ae. speltoides Ae. tauschii Gb El Bouhssini et al. (2008) H13 (6D); H22 (1DS); H23 (6D); H24 Lr54 Lr (5D) Lr59 Lr40 (1DS) Pm29 (7D) Pm34; Pm35 (5DL) Pm(39) Sbm1 Sr46 Ae. kotschyi Yr37 Ae. speltoides, uniaristata, umbellulata Ae. bicornis, biuncialis, columnaris, crassa, cylindrica, geniculata, neglecta, speltoides, tauschii Ae. sharonensis Friebe et al. 1991; Fedak et al. (2004) Gill et al. (1987); Ma et al. (1993); Raupp et al. (1993); Liu et al. (2005); Wang et al. (2006) Marais et al. (2005) Chhuneja et al. (2008b) Marais et al. (2008) Rowland and Kerber (1974); Raupp et al. (1983); Cox et al. (1992); Hussien et al. (1997); Huang and Gill (2001); Huang et al. (2003); Singh et al. (2004); Hiebert et al. (2007) Athwal and Kimber (1972) Buloichik et al. (2008) Bennett (1984) Zeller et al. (2002); Stoilova and Spetsov (2006) Olivera et al. (2007) Miranda et al. (2006); Qiu et al. (2006); Miranda et al. (2007) Zhu et al. (2006) Buloichik et al. (2008) McKendry and Henke (1994) Narasimhamoorthy et al. (2006) Olivera et al. (2007) Gold et al. (1999); Faris et al. (2008) Mihova (1988); McIntosh et al. (2008); Sambasivam et al. (2008) Marais et al. (2005) Mihova (1988) Alam and Gustafson (1988) Olivera et al. (2007) (continued) 52 Table 1.10 (continued) Donor species Ae. tauschii Wheat curl mite Ae. tauschii Powdery 489 accesions of 19 species tested mildew, leaf rust, eyespot, glume blotch (b) Other traits investigated Aconitase Ae. longissima Ae. umbellulata Aluminum Ae. uniaristata tolerance Drought Ae. columnaris, geniculata, kotschyi, tolerance longissima, peregrina, sharonensis, tauschii, triuncialis, umbellulata Endopeptidase Ae. bicornis Ae. longissima Ae. umbellulata Frost tolerance Ae. cylindrica, neglecta, tauschii, triuncialis, umbellulata Grain protein Ae. longissima percentage Grain hardness Ae. bicornis, longissima, searsii, protein sharonensis, speltoides Grain softness Ae. tauschii protein Grain weight Ae. longissima Heat tolerance Ae. longissima, searsii, speltoides (vegetative phase) HMW and Ae. tauschii, longissima, umbellulata LMW, Gliadin subunits Ae. umbellulata Ae. umbellulata Ae. speltoides Peroxidase Ae. longissima Salt tolerance Ae. comosa, crassa, cylindrica, geniculata, neglecta, juvenalis, kotschyi, tauschii, triuncialis, umbellulata, vavilovii Subtilisin Ae. longissima inhibitor Ae. umbellulata Tolerance to Mn Ae. speltoides toxicity Tolerance to Aegilops species with U-genome zinc defficiency Trypsin inhibitor Ae. mutica Ae. sharonensis Nucleolus organizer regions B. Kilian et al. Gene(s) studied and chromosome positions, the genome of bread wheat Tsr3 Cmc1; Cmc4 Aco-S (6S) beta-Amy-U1 Ep-S (7S) Ep-U1 (1U) Pina and PinbS1, Sb1, Sl1, Ss, Ssh GspD1 Reference Tadesse et al. (2006) Conner et al. (1991); Malik et al. (2003) Börner et al. (2006) Chenicek and Hart (1987) Ainsworth et al. (1987) Miller et al. (1995, 1997) Damania et al. (1992); Waines et al. (1993); Rekika et al. (1998); Monneveux et al. (2000); Farooq and Azam (2001) Koebner et al. (1988) Hart and Tuleen (1983) Koebner et al. (1988) Limin and Fowler (1981); Monneveux et al. (2000) Levy et al. (1985) Morris et al. (2001); Lillemo et al. (2002); Massa et al. (2004) Massa et al. (2004) Millet et al. (1988) Waines (1994) GluD1, GluSl, GluU, GliD, GliSl, GliU Nor-U1 (1U) Nor-U3 (5U) Nor-2 (6S) Per-S (2S) Si-S (1S) Si-U2 (1U) Shepherd (1973); Brown et al. (1979); Lagudah and Halloran (1988); Gupta and Shepherd (1990); Hueros et al. (1991); William et al. (1993); RodriguezQuijano and Carrillo (1996);RodriguezQuijano et al. (1996) Gianibelli et al. (2001, 2002a, b) Martini et al. (1982) Martini et al. (1982) Dvorak et al. (1984) Liu and Gale (1990) Farooq et al. (1989); Rekika et al. (1998); Monneveux et al. (2000); Farooq and Azam (2001) Koebner (1990) Koebner (1990) Dinev and Netcheva (1995) Cakmak et al. (1999) Ti-M (5M) Ti-S (5S) Koebner (1987) Koebner (1987) 1 Aegilops wheat seeds. According to this, the female line is an alloplasmic wheat cultivar in a sterilizing cytoplasm and the male parent is another wheat cultivar having the restorer gene(s), natural or transferred to it from an Aegilops species. The female line is maintained by a male fertile euplasmic wheat line that is genomically identical to the female line. Such a system has been realized with T. timopheevii cytoplasm but not with Aegilops cytoplasm. Attempts were carried out to produce such an alloplasmic female line from a wheat cultivar having the 1BL/1RS translocation from rye and Ae. peregrina (Ss) cytoplasm (Feldman and Millet unpublished). Since the Rf genes for this cytoplasm are located on 1BS, which is missing in this cultivar, the alloplasmic plant is male sterile and its hybrid is restored by a normal (non 1B/1R) wheat cultivar. However, this alloplasmic female, when cross pollinated, produced twin and embryoless seeds (Tsunewaki et al. 1974), and fertility restoration was incomplete. Moreover, a decrease in chlorophyll content and grain yield in similar fertile alloplasmic cultivars renders this cytoplasm unsuitable for hybrid production (Feldman and Millet unpublished) 1.7.4.2 Induction of Haploid Production in Wheat Six Aegilops cytoplasms induced haploids at the considerable rate of 11–56% in alloplasmic wheat with a translocated 1BL/1RS chromosome pollinated by the wheat parent (Kihara and Tsunewaki 1962; Tsunewaki et al. 1974). Cytoplasms of these species, namely Ae. columnaris, Ae. kotschyi, Ae. markgrafii, Ae. peregrina, Ae. umbellulata, and Ae. triuncialis, which possess either cytoplasm type U2, S2, C, Ss, or U (see Table 1.2), induced haploid production as a result of a high frequency of parthenogenesis in the egg cells (Tsunewaki et al. 1974). Haploid production may be used to accelerate breeding programs by obtaining homozygous double haploids. 1.7.4.3 Production of Deletion Lines by Gametocidal Genes It has been shown by Endo (1988) that a monosomic addition of chromosome 2C of Ae. cylindrica causes 53 chromosome breakage in progenies not having it. This is ascribed to the gametocidal effect of this chromosome (Endo 1990). More chromosomes of other Aegilops species are also described. This feature has been used to produce deletion stocks of common wheat (430 lines). These lines involve all the 21 wheat chromosomes, with terminal deletions of various lengths (Endo and Gill 1996). Three Aegilops species with gametocidal capacity, namely Ae. cylindrica, Ae. triuncialis, and Ae. speltoides, were used to produce these stocks. The deletion stocks show phenotypic variations depending on the size of the chromosomal deficiency and serve as a tool for physical mapping of wheat chromosomes. 1.8 Genomic Resources A number of genomic resources have been developed or are being developed for wheat and the Triticeae by international cooperation efforts. Due to the large (17 Gb) and complex hexaploid wheat genome, at the moment the diploid barley (Hordeum vulgare L.) is considered the Triticeae model species. Barley genome research develops cutting-edge tools that can be used for wheat genomics. It can be expected that these efforts will include, in the near future, Aegilops as well. Selected examples for these organizations are (1) ITMI (International Triticeae Mapping Initiative, http://wheat.pw.usda.gov/ITMI/). ITMI was established to provide support in the coordination of research efforts in molecular genetics, genomics, and genetic analysis of the Triticeae. Coordinated topics also include Aegilops, genetics of abiotic stress resistance, and Triticeae informatics. (2) ETGI (European Triticeae Genomics Initiative, http://pgrc.ipk-gatersleben.de/etgi/). ETGI is a platform for the coordination and representation of Triticeae Genomics Research at the European level and serves as a link to the international research community represented by ITMI. (3) IGROW (International Genome Research on Wheat, http://www.k-state.edu/ igrow/IGROW_history.html). (4) IWGSC (International Wheat Genome Sequencing Consortium, http:// www.wheatgenome.org/). 54 1.8.1 Databases Several databases and resources have been established that aim to curate the increasing amount of genomic information. Selected databases are: 1. GrainGenes, http://www.graingenes.org. This is the international database for the wheat, barley, rye, and oat genomes. For these species, it is the primary repository for information on genetic maps, mapping probes and primers, genes, alleles, and QTLs. Documentation includes primer sequences, polymorphism descriptions, genotype and trait scoring data, experimental protocols, photographs of marker polymorphisms, disease symptoms, and mutant phenotypes. These data are integrated with sequence and bibliographic records selected from external databases and results of BLAST searches of the ESTs. 2. BLAST databases. These databases are maintained locally and serve local research activities. Custom databases are set up to screen against Triticeae sequences, assemblies, cDNA libraries, and other specialty formatted databases (http:// blast.ncbi.nlm.nih.gov/Blast.cgi). 3. cerealsDB.uk.net (http://www.cerealsdb.uk.net/ index.htm). Maintained at the University of Bristol for investigating gene functions in cereals. 4. wEST-SQL database (http://wheat.pw.usda.gov/ wEST/). This is a USDA-ARS sponsored server of nucleic acid sequence data for Triticeaeassociated research projects. 5. Gramene (http://www.gramene.org/). It is a curated data resource for comparative genome analysis in the grasses. 6. TIGR Wheat genome database (http://www.tigr. org/tdb/e2k1/tae1/). A bioinformatics resource for annotating and analyzing the wheat genome. 7. HarvEST is mainly an expressed sequence tag (EST) database-viewing software that emphasizes gene function oriented to comparative genomics and the design of oligonucleotides, in support of activities such as microarray content design, function annotation, and physical and genetic mapping (http://harvest.ucr.edu/). 8. TREP, the Triticeae Repeat Sequence Database. It contains a collection of repetitive DNA sequences from different Triticeae species (http://wheat.pw. usda.gov/ITMI/Repeats/index.shtml). B. Kilian et al. 9. Wheat D-Genome by Physical Mapping (http:// wheat.pw.usda.gov/PhysicalMapping/). The database has been developed to assess gene distribution across the D-genome chromosomes. The Aegilops tauschii genome is homologous with the D-genome of wheat. Physical maps of each of the seven Ae. tauschii chromosomes are constructed and a large number of gene loci are placed on the physical maps. The physical maps will be integrated with the wheat linkage and deletion maps. 10. TriAnnot Project (http://urgi.versailles.inra.fr/ projects/TriAnnot/). Aims at deciphering the chromosomal location and biological function of wheat genes. The aim of TriAnnot pipeline is to provide a wheat and barley automated annotation. 11. TriMEDB, Triticeae Mapped EST database (http://trimedb.psc.riken.jp/index.pl). It provides information on mapped cDNA markers that are related between barley and wheat, along with various annotations. 1.8.2 Linkage Maps Molecular linkage maps are under development in almost all crop species. To explore the genetic relationships in the Triticeae and to facilitate the transfer of agronomically important genes, genetic maps as well as linkage maps have been developed also for Aegilops. Currently, six diploid wheat genetic maps are available (Table 1.11), which have been developed to map disease-resistant genes. The first genetic restriction fragment length polymorphism (RFLP)-based linkage map of Aegilops tauschii (DD) was developed by Gill et al. (1991b) to study the relationship of the D-genome of bread wheat with Ae. tauschii. This linkage map contains 178 markers. Thirty-five loci were mapped by aneuploid analysis in T. aestivum. One hundred and fifty-two loci, including 143 RFLPs, eight proteins, and one leaf rust resistance gene, were mapped in an F2 population (60 plants) of Ae. tauschii. One hundred and twenty-seven loci were placed in linkage groups belonging to seven D-genome chromosomes of Ae. tauschii. A more saturated linkage map was developed for Ae. tauschii with 546 loci and 164 agronomically 1 Aegilops 55 Table 1.11 Genetic linkage maps available for Aegilops species Species Year Parent (♀) Parent (♂) Marker No. of marker type Ae. tauschii 1991 TA1691 TA1704 RFLP 291 Ae. tauschii 2000 AUS 18913 CPI 110856 RFLP 24 Ae. tauschii 2000 AUS 18913 CPI 110856 RFLP 17 Ae. tauschii RFLP 123 Ae. longissima, 2001 Y154-1 Y431-1 RFLP YY Ae. umbellulata, 1998 JIC2010001 JIC2010003 RFLP AC Maps Reference 1D–7D 1D 1D 1D–7D Gill et al. (1991a, 1992) Spielmeyer et al. (2000a) Spielmeyer et al. (2000b) http://wheat.pw.usda.gov/cgi-bin/graingenes/ report.cgi?class¼mapdata&name¼T.tauschii %2C%20Appels Zhang et al. (2001) 74 1S–7S 89 1U–7U Zhang et al. (1998) important genes (Boyko et al. 1999). This map was compared with T. aestivum, and discrepancies were found between the orders of the markers on chromosomes 4D, 5D, and 7D of Ae. tauschii with the genetic and physical map of T. aestivum. Another detailed RFLP map was constructed by Spielmeyer et al. (2000a) for the distal end of the short arm of chromosome 1D of Ae. tauschii (AUS18911, carrying Lr21 and Sr45) and wheat (CPI 110799, carrying the stem rust resistance gene Sr33). Large DNA fragments isolated from a BAC library of Ae. tauschii were used by Spielmeyer et al. (2000b) to determine the relationship between physical and genetic distance at seed storage protein loci located at the distal end of chromosome 1DS. Highly recombinogenic regions were identified where the ratio of physical to genetic distance was estimated to be smaller than 20 kb/cM. Fifty-eight F2 individuals were sufficient to identify recombinants between most of the mapped RFLP markers. A higher recombination frequency was observed between and within Glu-D3 and Gli-D1 in Ae. tauschii, as compared to previous studies in the corresponding loci of the D-genome of the hexaploid wheat. Variation was reported at seed storage protein loci among Ae. tauschii accessions from diverse geographical origins (Lagudah and Halloran 1988). Most of the 79 accessions were distinguished on the basis of unique gliadin (Gli-D1) haplotypes. Such high levels of diagnostic haplotypes occurring in Ae. tauschii could be accounted for by the relatively high recombination frequency among the Gli-D1 loci. A comparative genetic map of the Ae. longissima genome was developed by Zhang et al. (2001) using RFLP probes with known locations in wheat. A high degree of conserved colinearity was observed between the wild diploid Ae. longissima and the wheat genome. Chromosomes 1Sl, 2Sl, 3Sl, 5Sl, and 6Sl were colinear with wheat chromosomes 1D, 2D, 3D, 5D, and 6D, respectively. The analysis confirmed that chromosomes 4Sl and 7Sl were translocated relative to wheat. The short arms and large part of the long arms were homoeologous to most of wheat chromosomes 4D and 7D, respectively, but the distal segment of 7D was translocated from 7SlL to the distal region of 4SlL. The map and RFLP markers were used to analyze a set of “Chinese Spring” (CS)/ Ae. longissima chromosome addition lines. The availability of disomic CS/Ae. longissima addition lines for chromosomes 1Sl, 2Sl, 3Sl, 4Sl, and 5Sl was evident. A set of Ae. sharonensis chromosome addition lines was also available for analysis. Due to the gametocidal nature of Ae. sharonensis chromosomes 2Sl and 4Sl, additions 1Sl, 3Sl, 5Sl, 6Sl, and 7Sl were produced in a (4D) 4Sl background, and 2Sl and 4Sl in a euploid wheat background. The 4/7 translocation found in Ae. longissima was also evident for Ae. sharonensis. Zhang et al. (1998) developed a comparative genetic map of Ae. umbellulata using probes previously mapped in hexaploid wheat. All seven Ae. umbellulata chromosomes displayed one or more rearrangements relative to wheat. These structural changes were consistent with the subterminal morphology of chromosomes 2U, 3U, 6U, and 7U. Comparison of the chromosomal locations assigned by mapping and those obtained by hybridization to wheat/Ae. umbellulata single chromosome addition lines supported the identification of the added Ae. umbellulata chromosomes and indicated that no cytological rearrangements had taken place during the production of the alien wheat aneuploid lines. 56 1.8.3 BAC Libraries The availability of a large-insert genomic library is considered an absolute prerequisite for positional gene cloning. Large-insert libraries are also indispensable for studies of genome structure. Bacterial artificial chromosomes (BACs) have proven to be the most versatile vectors for the construction of such libraries (Shizuya et al. 1992). They are easy to maintain and reproduce, have low levels of chimerism, and are easy to screen by DNA hybridization. Massive efforts are underway to develop physical maps of bread wheat. BAC clone-based physical maps have been developed already for wheat chromosome 3B (Paux et al. 2008). These efforts ultimately will lead to whole wheat genome sequencing. Seven BAC libraries are available for Aegilops tauschii (wheat Dgenome donor) and one BAC library for Ae. speltoides (wheat B-genome donor) (Table 1.12; Moullet et al. 1999; Akhunov et al. 2005). Moullet et al. (1999) have used the Ae. tauschii accession Aus18913 for the construction and characterization of a large DNA insert library from the Dgenome of wheat. The library consists of 144,000 clones with an average insert size of 119 kb. The accession Aus18913 contains several genes of economic importance, among which the cereal cyst nematoderesistant gene Cre3 (syn. CcnD1), the HMW glutenin subunits Dx2 and DyT2, and an unusual HMW gliadindesignated T1 (Lagudah and Halloran 1988), as well as resistance to stem, leaf, and stripe rusts. Akhunov et al. (2005) reported the construction and characterization of large-insert BAC libraries for Triticum urartu, Ae. speltoides, and Ae. tauschii. The libraries are equivalent to 3.7, 5.4, and 4.1 of the T. urartu, Ae. speltoides, and Ae. tauschii genomes, B. Kilian et al. respectively. The libraries were used to estimate the proportion of known repeated nucleotide sequences and gene content in each genome by BAC-end sequencing. Repeated sequence families previously detected in Triticeae accounted for 57%, 61%, and 57% of the T. urartu, Ae. speltoides, and Ae. tauschii genomes, and coding regions accounted for 5.8%, 4.5%, and 4.8%, respectively. The estimated average size of inserts in T. urartu, Ae. speltoides, and Ae. tauschii libraries was 110 kb, 115 kb, and 115 kb, respectively (Lijavetzky et al. 1999; Yu et al. 2000; Allouis et al. 2003; Cenci et al. 2003; Nilmalgoda et al. 2003). The successful recovery of all single-copy genes used for hybridization indicated that these three BAC libraries are valuable tools for genomic studies and gene isolation. BAC clone information were essential for marker development in the Lr34 region (Bossolini et al. 2006), which led to the cloning of the Lr34 gene (Krattinger et al. 2009). The Ae. tauschii accession AS75 was chosen as the parent of a high resolution mapping population used for anchoring AL8/78 BAC contigs on the Ae. tauschii genetic map (Dvorak et al. 1998b; Luo et al. 2009). Ae. speltoides is an outcrosser, and the F4 family from the cross Ae. speltoides 2-12-4-8-1-1-1 Ae. speltoides PI36909-12-II was used for the construction of the Ae. speltoides library. The family was homozygous for two Ph1 suppressor genes (Chen and Dvorak 1984). Salse et al. (2008) screened BAC libraries from the bread wheat cultivar T. aestivum cv. Renan and from Ae. speltoides with PCR markers for the Storage Protein Activator (SPA) locus. They sequenced the longest BAC clones from genomes A-, B-, D-, and S-. Non-shared transposable elements (TE) insertions within the SPA orthologous gene locus were selected for evolutionary studies (see above). Table 1.12 BAC resources available for Aegilops species (http://www.wheatgenome.org/projects.php; http://www.plantsciences. ucdavis.edu/Dubcovsky/BAC-library/ITMIbac/ITMIBAC.htm) Species Accession Vector Restriction site No. of clones Clone size (kb) Coverage Curator Ae. tauschii AL8/78 pECBAC1 EcoR I 54,000 167 2.2X H.B. Zhang Ae. tauschii AL8/78 pECBAC1 Hind III 59,000 189 2.2X H.B. Zhang Ae. tauschii AL8/78 pCLDO4541 Hind III 52,000 190 3.2X H.B. Zhang Ae. tauschii AL8/78 pECBAC1 BamH I 59,000 149 2.8X H.B. Zhang Ae. tauschii AL8/78 pCLDO4541 BamH I 76,000 174 2.4X H.B. Zhang Ae. tauschii Aus 18913 pCLDO4541 Hind III 144,000 120 4.2X E. Lagudah Ae. tauschii AS75 pECBAC1 BamH I 181,248 115 4.1X J. Dvorak Ae. speltoides 2-12-4-8-1-1-1 pECBAC1 BamH I 237,312 115 5.4X J. Dvorak 1 Aegilops Current techniques of screening BAC libraries of large eukaryotic genomes with molecular markers during the construction of physical maps are slow and laborious. Recently however, Luo et al. (2009) reported a new high-throughput strategy for screening BAC libraries and anchoring of clones on a genetic map based on single nucleotide polymorphisms (SNPs). 1.8.4 Sequences Available Three types of studies have produced sequence data of Aegilops: Phylogenetic studies, the search for new disease-resistant alleles and, more recently, activities dedicated to the sequencing of the whole bread wheat genome. An overview of Aegilops sequences released at GenBank database (http://www.ncbi.nlm.nih.gov/ Genbank/) is shown in Table 1.13. It is evident that few sequences have been released for most Aegilops species. Furthermore, in the database, the ratio chloroplast to nuclear sequences indicates that still relatively few nuclear loci have been sequenced in Aegilops. The chloroplast sequences have been mainly used for phylogenetic studies. Compared to other Aegilops species, more sequence information is available for Ae. speltoides and Ae. tauschii as they are the species most related to the B- and D-genomes of bread wheat, respectively. Genome sequencing projects are ongoing in Ae. tauschii and Ae. umbellulata. 1.9 Conservation Initiatives Aegilops species have hidden and unexplored potential for wheat improvement. On the other hand, there has been a considerable loss of Aegilops germplasm due to an increase of urbanization, as well as loss of natural habitat (Anikster and Noy-Meir 1991; Hawkes et al. 2000). There is only one report of endangered Ae. sharonensis populations that were rescued just before the destruction of their habitats (Millet 2006). Aegilops species need to be conserved in situ in their natural habitats if genetic diversity has to be preserved. Greater emphasis on in situ conservation of genetic diversity is required, employing also ex situ conserva- 57 tion in genebanks as a safety back-up (Hammer 1980b). Maxted et al. (2008) discuss Aegilops conservation based on a compiled dataset of 9,866 unique germplasm accessions described in four datasets (duplicate observations and observations outside the natural distribution range were removed, and only 36% of the original accessions were considered). Aegilops datasets were from (I) “Global Database of Wheat Wild Relatives” (at ICARDA; 12,476 accessions), (II) “CGIAR system-wide information network for genetic resources” (SINGER – http://singer.grinfo.net; 3,569 accessions), (III) “European Plant Genetic Resources” (EURISCO– http://eurisco.ecpgr.org/index.php; 7,684 accessions), and (IV) “Germplasm Resources Information Network” (GRIN – http://www.ars-grin.gov/ cgi-bin/npgs/html/index.pl; 3,626 accessions). The combined, corrected dataset of Aegilops germplasm accessions was then analyzed by ex situ conservation gap analysis. The ecogeographic analysis of Aegilops species found that all 21 species are represented in ex situ collections, but the number of accessions varies considerably. Potential undersampled areas were identified and the size and range of these predicted conservation gaps varied considerably between species. This process highlighted ex situ conservation priorities for Aegilops species in Cyprus, Egypt, Greece, Iran, Israel, Libya, Spain, Syria, Tajikistan, Tunisia, Turkey, Turkmenistan, and Uzbekistan, as well the priority in conservation for Ae. bicornis, Ae. comosa, Ae. vavilovii, Ae. juvenalis, Ae. kotschyi, Ae. peregrina, Ae. sharonensis, and Ae. uniaristata. The most recent detailed overview of Aegilops genetic resources stored in ex situ genebank collections can be found in Kn€upffer (2009). Genetic diversity studies have demonstrated extensive genetic diversity in the original populations of the wild gene pool in the natural habitat. This diversity, however, is impossible to preserve by standard ex situ collection procedures (Valkoun and Damania 1992). In addition, it is an accepted rule that during field collection trips only few plants per site are sampled. On the other hand, under in situ conservation, a much larger and continuously evolving genetic diversity is preserved. Germplasm could be repeatedly collected from in situ conservation sites for evaluations. Longterm monitoring of biodiversity at in situ conservation sites is essential, and the sites should be actively managed to limit grazing. In situ conservation of cereals has been of interest and studied since several decades, and few protected 58 B. Kilian et al. Table 1.13 Overview of Aegilops sequences released in GenBank database (http://www.ncbi.nlm.nih.gov/) Nucleotide Nucleotide Popsetg UniSTSh Protein Nucleotide cpb mic nd ESTe GSSf totala Aegilops bicornis 117 38 79 24 77 Aegilops biuncialis 75 70 5 7 31 Aegilops 79 56 23 8 34 columnaris Aegilops comosa 144 84 60 20 45 Aegilops crassa 62 42 1 19 9 33 Aegilops cylindrica 84 72 12 8 38 Aegilops geniculata 106 77 29 8 44 Aegilops juvenalis 30 11 19 11 12 Aegilops kotschyi 74 50 24 10 38 Aegilops 228 43 185 1 23 113 longissima Aegilops 125 33 92 25 80 sharonensis Aegilops markgrafii 202 146 56 18 42 64 Aegilops mutica 59 46 13 12 16 Aegilops neglecta 92 70 22 8 33 Aegilops peregrina 86 71 15 7 35 Aegilops searsii 141 40 101 21 94 Aegilops speltoides 547 102 445 4,315 90 300 Aegilops tauschii 1,327 75 1 1,251 116 5,055 49 4 510 Aegilops triuncialis 303 287 16 10 123 Aegilops 165 115 50 15 15 20 umbellulata Aegilops 67 38 29 17 1 uniaristata Aegilops vavilovii 12 0 12 3 29 Aegilops ventricosa 52 30 22 8 Genome projects ongoing Dvorak et al. Gill et al. State: Early January 2009 Note: aTotal nucleotide sequences (NCBI); bChloroplast sequences (NCBI); cMitochondrial sequences (NCBI); dNucleotide sequences excluding 2 and 3; eSingle read cDNA sequences (annotated biological features not included); fGenome Survey Sequences first single-read genomic sequences (rarely include biological features); gPopulation study data sets sequences collected to study the evolutionary relatedness of populations. Different members of same the species or from different species; hMarkers or sequence tagged sites sites have been established (Damania 1994; Stolton et al. 2006; Maxted et al. 2008). (1) Ammiad in Galilee/Israel (Anikster and Noy-Meir 1991; Horovitz and Feldman 1991; Noy-Meir et al. 1991; Anikster et al. 1997; Kaplan 2008); (2) the Erebuni Nature Reserve in Armenia (Vavilov 1951); and (3) the Ceylanpinar State Farm in southeastern Turkey (Karagöz 1998). The spatial analysis of Aegilops species diversity by Maxted et al. (2008) identified five potential areas for the optimal locations of further in situ conservation reserves for Aegilops species. The regions identified were located in (1) central Israel; (2) northern Lebanon and Syria; (3) northwestern Turkey; (4) Turkmenistan; and (5) southern France. Maxted et al. (2008) recommended that at least one genetic reserve should be created in each of the regions identified. 1.10 Conclusions and Final Considerations Several aspects concerning the genus Aegilops L. have been reviewed in this chapter. We have considered 21 annual species and followed in their classification the monographs of Hammer (1980a, b) and van Slageren (1994). We have shown that Aegilops species have been closely involved in wheat evolution, played a major role in wheat domestication and will play a critical role in future wheat improvement. The keys to obtain deeper insights to Aegilops genetic diversity, Aegilops–Triticum molecular biological relationships, and to harvest and preserve suitable alleles for future wheat improvement are (1) a 1 Aegilops comprehensive germplasm collection covering the whole distribution area of each species; (2) the comparison of several accessions for each species considering all ploidy levels; (3) the use of new molecular fingerprinting techniques and the access to highthroughput sequencing technologies (Goldberg et al. 2006; Wicker et al. 2006); and (4) the improvement of analytical methods capable of treating various issues based on mathematical and statistical models (Pluzhnikov and Donnelly 1996; Thuillet et al. 2005; Haudry et al. 2007). New genomic resources for future plant breeding have to be developed. International consortia, such as the International Triticeae Mapping Initiative (ITMI) and the International Wheat Genome Sequencing Consortium (IWGSC), will lead to accelerated gene discovery and will shed new light on mechanisms that have shaped the wheat and Aegilops genomes during their evolution. Archeological excavation campaigns should also consider studies on Aegilops species. This will provide new information on ancient Aegilops distribution and their ecology. See Kilian et al. (2009) for a review on Triticeae domestication. In spite of more than 200 years of botanical exploration of the Orient, resulting in many herbaria and germplasm collections, sequence data, and transferred alleles, our knowledge on the genus Aegilops is far from complete. We urgently need detailed studies for each species dealing with natural distribution range, ecology, soil, geomorphology, molecular resources, and genome sequences. There is an urgent need for an active in situ conservation to protect Aegilops species in their natural habitats. The human urbanization pressure increases, and the landscape, together with the farming practices, is rapidly changing. Already the establishment of new protected areas would be a success, while the existing reserves have to be enlarged in order to protect larger populations. Acknowledgments We are grateful to the “Ökotop GbR” company (Halle, Germany) and Alexander Walther for preparing the GIS based distribution maps. We thank B€arbel Schmidt, Ulrike Lohwasser, Matthias Kotter, and Klaus Pistrick (all at IPK Gatersleben) for providing Aegilops photographs. The authors are indebted to Moshe Feldman, Sigi Effgen, Andrea Brandolini, Naoki Mori, Shoji Ohta, George Willcox, Bill Martin, Reinder Neef, Ofer Bar-Yosef, Katia Badaeva, Klaus Schmidt, Peter Schreiber, J€ urgen Marlow, Michael 59 upffer, Andreas Börner, and all the participants Grau, Helmut Kn€ at the workshop “Cereal Diversity, Plant Domestication and Human History in the Fertile Crescent” in Turkey, 2009, for their valuable suggestions. Appendix Index to scientific names used for this chapter ¼ Register of species names Name Aegilemma kotschyi Aegilemma peregrina Aegilonearum juvenale Aegilopodes triuncialis Aegilops turcomanica Aegilops bicornis Aegilops bicornis var. anathera Aegilops bicornis var. bicornis Aegilops bicornis var. mutica Aegilops biuncialis Aegilops caudata Aegilops columnaris Aegilops comosa Aegilops comosa ssp. comosa Aegilops comosa var. comosa Aegilops comosa ssp. comosa var. comosa Aegilops comosa ssp. heldreichii Aegilops comosa var. subventricosa Aegilops crassa Aegilops crassa ssp. crassa Aegilops crassa ssp. vavilovii Aegilops crassa var. palaestina Aegilops cylindrica Aegilops geniculata Aegilops geniculata ssp. geniculata Aegilops geniculata ssp. gibberosa Aegilops juvenalis Aegilops kotschyi Aegilops ligustica Aegilops longissima Aegilops longissima ssp. longissima Aegilops longissima ssp. sharonensis Aegilops lorentii Aegilops markgrafii Aegilops markgrafii var. markgrafii Aegilops markgrafii var. polyathera Aegilops mutica Aegilops mutica ssp. loliacea Aegilops mutica var. loliacea Aegilops mutica ssp. mutica Aegilops mutica var. mutica (continued) 60 B. Kilian et al. Name Aegilops neglecta Aegilops neglecta ssp. neglecta Aegilops neglecta ssp. recta Aegilops ovata Aegilops peregrina Aegilops peregrina ssp. cylindrostachys Aegilops peregrina ssp. peregrina Aegilops peregrina var. peregrina Aegilops peregrina var. brachyathera Aegilops searsii Aegilops sharonensis Aegilops speltoides Aegilops speltoides ssp. ligustica Aegilops speltoides var. ligustica Aegilops speltoides ssp. speltoides Aegilops speltoides var. speltoides Aegilops squarrosa Aegilops tauschii Aegilops tauschii ssp. strangulata Aegilops tauschii ssp. tauschii Aegilops triaristata Aegilops triuncialis Aegilops triuncialis ssp. persica Aegilops triuncialis ssp. triuncialis Aegilops triuncialis ssp. triuncialis Aegilops triuncialis var. anathera Aegilops turcomanica Aegilops umbellulata Aegilops umbellulata ssp. transcaucasica Aegilops umbellulata ssp. umbellulata Aegilops uniaristata Aegilops variabilis Aegilops vavilovii Aegilops ventricosa Aegilotriticum Agropyron Amblyopyrum muticum Amblyopyrum muticum var. muticum Amblyopyrum muticum var. loliaceum Chennapyrum uniaristatum Comopyrum comosum Cylindropyrum cylindricum Gastropyrum crassum Gastropyrum vavilovii Gastropyrum ventricosum Gramineae Kiharapyrum umbellulatum Patropyrum tauschii Poaceae Pooideae Section Aegilops (continued) Name Section Comopyrum Section Cylindropyrum Section Sitopsis Section Vertebrata Sitopsis bicornis Sitopsis longissima Sitopsis searsii Sitopsis speltoides Subgenus Aegilops Subgenus Amblyopyrum Subgenus Sitopsis Triticeae Triticinae Tritordeum Triticosecale Triticum aestivum Triticum araraticum Triticum bicorne Triticum biunciale Triticum boeoticum Triticum carthlicum Triticum columnare Triticum comosum Triticum crassum Triticum cylindricum Triticum dichasians Triticum dicoccoides Triticum dicoccon Triticum juvenale Triticum kotschyi Triticum longissimum Triticum lorentii Triticum macrochaetum Triticum markgrafii Triticum monococcum Triticum neglectum Triticum ovatum Triticum parvicoccum Triticum peregrinum Triticum searsii Triticum speltoides Triticum syriacum Triticum tauschii Triticum tripsacoides Triticum triunciale Triticum triaristatum Triticum turanicum Triticum umbellulatum Triticum uniaristatum Triticum urartu Triticum ventricosum Triticum zhukovskyi 1 Aegilops References Adonina IG, Salina EA, Pestsova EG, Röder MS (2005) Transferability of wheat microsatellites to diploid Aegilops species and determination of chromosomal localizations of microsatellites in the S genome. Genome 48:959–970 Aghaee-Sarbarzeh M, Ferrahi M, Singh S, Singh H, Friebe B, Gill BS, Dhaliwal HS (2002) PhI -induced transfer of leaf and stripe rust-resistance genes from Aegilops triuncialis and Ae. geniculata to bread wheat. Euphytica 127:377–382 Ainsworth CC, Miller TE, Gale MD (1987) a-amylase and bamylase homoeoloci in species related to wheat. Genet Res 49:93–103 Akhunov ED, Akhunova AR, Dvorak J (2005) BAC libraries of Triticum urartu, Aegilops speltoides and Ae. tauschii, the diploid ancestors of polyploidy wheat. Theor Appl Genet 111:1617–1622 Alam KB, Gustafson JP (1988) Tan-spot resistance screening of Aegilops species. Plant Breed 100:112–118 Allaby RG, Brown TA (2001) Network analysis provides insights into evolution of 5S rDNA arrays in Triticum and Aegilops. Genetics 157:1331–1341 Allouis S, Moore G, Bellec A, Sharp R, Faivre Rampant P, Mortimer K, Pateyron S, Foote TN, Griffiths S, Caboche M, Chalhoub B (2003) Construction and characterisation of a hexaploid wheat (Triticum aestivum L.) BAC library from the reference germplasm ‘Chinese Spring’. Cereal Res Commun 31:331–338 Alonso LC, Kimber G (1981) The analysis of meiosis in hybrids. II. Triploid hybrids. Can J Genet Cytol 23:221–234 Anikster Y, Noy-Meir I (1991) The wild-wheat field laboratory at Ammiad. Isr J Bot 40:351–362 Anikster Y, Feldman M, Horowitz A (1997) The Ammiad experiment. In: Maxted N, Ford-Lloyd BV, Hawkes JG (eds) Plant genetic conservation: the in situ approach. Chapman and Hall, London, UK, pp 239–253 Ankory H, Zohary D (1962) Natural hybridization between Aegilops longissima and Ae. sharonensis: a morphological and cytological study. Cytologia 27:314–315 Arraiano LS, Worland AJ, Ellerbrook C, Brown JKM (2001) Chromosomal location of a gene for resistance to Septoria tritici blotch (Mycosphaerella graminicola) in a hexaploid wheat ‘Synthetic 6x’. Theor Appl Genet 103:758–764 Athwal RS, Kimber G (1972) The pairing of an alien chromosome with homoeologous chromosomes of wheat. Can J Genet Cytol 14:325–333 Azzi G (1954) Ecologie agricole. Baillére, Paris, France Badaeva ED, Amosova AV, Muravenko OV, Samatadze TE, Chikida NN, Zelenin AV, Friebe B, Gill BS (2002) Genome differentiation in Aegilops. 3. Evolution of the D-genome cluster. Plant Syst Evol 231:163–190 Badaeva ED, Amosova AV, Samatadze TE, Zoshchuk SA, Shostak NG, Chikida NN, Zelenin AV, Raupp WJ, Friebe B, Gill BS (2004) Genome differentiation in Aegilops. 4. Evolution of the U-genome cluster. Plant Syst Evol 246:45–76 Bai D, Scoles G, Knott D (1994) Transfer of leaf rust and stem rust resistance from Triticum triaristatum to durum and bread wheats and their molecular cytogenetic localization. Genome 37:410–418 61 Bai D, Scoles GJ, Knott DR (1995) Rust resistance in Triticum cylindricum Ces. (4x, CCDD) and its transfer into durum and hexaploid wheats. Genome 38:8–16 Bariana HS, McIntosh RA (1993) Cytogenetic studies in wheat. XV. Location of rust resistance genes in VPM1 and their genetic linkage with other disease resistance genes in chromosome 2A. Genome 36:476–482 Bariana HS, McIntosh RA (1994) Characterisation and origin of rust and powdery mildew resistance genes in VPM1 wheat. Euphytica 76:53–61 Barloy D, Lemoin J, Dedryver F, Jahier J (2000) Identification of molecular markers linked to the Aegilops variabilisderived root knot nematode resistance gene Rkn-mn1 in wheat. Plant Breed 118:169–172 Baum BR, Edwards T, Johnson DA (2009) Phylogenetic relationships among diploid Aegilops species inferred from 5S rDNA units. Mol Phylogen Evol 53:34–44. Bennett GAF (1984) Resistance to powdery mildew in wheat: a review of its use in agriculture and breeding programmes. Plant Pathol 33:279–300 Bhave M, Morris CF (2008a) Molecular genetics of puroindolines and related genes: regulation of expression, membrane binding properties and applications. Plant Mol Biol 66: 221–231 Bhave M, Morris CF (2008b) Molecular genetics of puroindolines and related genes: allelic diversity in wheat and other grasses. Plant Mol Biol 66:205–219 Blaszczyk L, Goyeau H, Huang XQ, Röder M, Stepień L, Chełkowski J (2004) Identifying leaf rust resistance genes and mapping gene Lr37 on the microsatellite map of wheat. Cell Mol Biol Lett 9(4B):869–878 Boguslavsky L (1979) Flowering, pollination and spontaneous hybridization in the genus Aegilops L. (in Russian). PhD Thesis, Vavilov All-Russian Institute of Plant Industry, St. Petersburg, Russia Bor NL (1968) Aegilops L. In: Townsend CC, Guest E, Al-Rawi A (eds) Flora of Iraq, vol 9. Iraq Ministry of Agriculture, Baghdad, pp 173–197 Bossolini E, Krattinger SG, Keller B (2006) Development of simple sequence repeat markers specific for the Lr34 resistance region of wheat using sequence information from rice and Aegilops tauschii. Theor Appl Genet 113:1049–1062 Bowden WM (1959) The taxonomy and nomenclature of the wheats, barleys, and ryes and their wild relatives. Can J Bot 37:657–684 Boyko EV, Gill KS, Mickelson-Young L, Nasuda S, Raupp WJ, Ziegle JN, Singh S, Hassawi DS, Fritz AK, Namuth D, Lapitan NLV, Gill BS (1999) A high-density linkage map of Aegilops tauschii, the D-genome progenitor of wheat. Theor Appl Genet 99:16–26 Börner A, Korzun V, Worland AJ (1998) Comparative genetic mapping of loci affecting plant height and development in cereals. Euphytica 100:245–248 Börner A, Freytag U, Sperling U (2006) Analysis of wheat disease resistance data originating from screenings of Gatersleben genebank accessions during 1933 and 1992. Genet Resour Crop Evol 53:453–465 Brown JWS, Kemble RJ, Law CN, Flavell RB (1979) Control of Endosperm proteins in Triticum aestivum (var. Chinese Spring) by homoeologous group 1 chromosomes. Genetics 93:189–200 62 Buloichik AA, Borzyak VS, Voluevich EA (2008) Influence of alien chromosomes on the resistance of soft wheat to biotrophic fungal pathogens. Cytol Genet 42:9–15 Cakmak I, Tolay I, Ozkan H, Ozdemir A, Braun HJ (1999) Variation in zinc efficiency among and within Aegilops species. J Plant Nutr Soil Sci 162:257–262 Calder DM (1966) Inflorescence induction and initiation in the Gramineae. In: Milthorpe FL, Ivins JD (eds) The growth of cereals and grasses. Butterworths, London, UK, pp 59–73 Cenci A, D’Ovidio R, Tanzarella OA, Ceoloni C, Porceddu E (1999) Identification of molecular markers linked to Pm13, an Aegilops longissima gene conferring resistance to powdery mildew in wheat. Theor Appl Genet 98:448–454 Cenci A, Chantret N, Kong X, Gu Y, Anderson OD, Fahima T, Distelfeld A, Dubcovsky J (2003) Construction and characterization of a half million clone BAC library of durum wheat (Triticum turgidum ssp. durum). Theor Appl Genet 107:931–939 Ceoloni C, Del Signore G, Pasquini M, Testa M (1988) Transfer of mildew resistance from Triticum longissimum into wheat by ph1 induced homoeologous recombination. In: Miller TE, Koebner RMD (eds) Proceedings of the 7th international wheat genetics symposium. Cambridge University Press, Cambridge, UK, pp 221–226 Ceoloni C, Donini P (1993) Combining mutations of two homoeologous pairing suppressor genes Ph1 and Ph2 in common wheat and in hybrids with alien Triticeae. Genome 36: 377–386 Ceoloni C, Forte P, Gennaro A, Micali S, Carozza R, Bitti A (2005) Recent developments in durum wheat chromosome engineering. Cytogenet Genome Res 109:328–334 Chalupska D, Lee HY, Faris JD, Evrard A, Chaloub B, Haselkorn R, Gornicki P (2008) Acc homoeoloci and the evolution of wheat genomes. Proc Natl Acad Sci USA 105:9691–9696 Chantret N, Cenci A, Sabot F, Anderson O, Dubcovsky J (2004) Sequencing of the Triticum monococcum hardness locus reveals good microcolinearity with rice. Mol Genet Genomics 271:377–386 Chantret N, Salse J, Sabot F, Rahman S, Bellec A, Laubin B, Dubois I, Sourdille P, Joudrier P, Gautier M-F, Cattolico L, Beckert M, Aubourg S, Weissenbach J, Caboche M, Bernard M, Leroy P, Chalhoub B (2005) Molecular basis of evolutionary events that shaped the hardness locus in diploid and polyploid wheat species (Triticum and Aegilops). Plant Cell 17:1033–1045 Chao S, Sharp PJ, Worland AJ, Warham EJ, Koebner RMD, Gale MD (1989) RFLP-based genetic maps of wheat homologous group 7 chromosomes. Theor Appl Genet 78: 495–504 Chapman V, Riley R (1970) Homoeologous meiotic chromosome pairing in Triticum aestivum in which chromosome 5B is replaced by an alien homoeologue. Nature 226:376–377 Chen KC, Dvorak J (1984) The inheritance of genetic variation in Triticum speltoides affecting heterogenetic chromosome pairing in hybrids with Triticum aestivum. Can J Genet Cytol 26:279–287 Chen PD, Tsujimoto H, Gill BS (1994) Transfer of PhI genes promoting homoeologous pairing from Triticum speltoides to common wheat. Theor Appl Genet 88:97–101 Chen SW, Chen PD, Wang XE (2008) Inducement of chromosome translocation with small alien segments by irradiation B. Kilian et al. mature female gametes of the whole arm translocation line. Sci China Ser C Life Sci 51:346–352 Chenicek KJ, Hart GE (1987) Identification and chromosomal locations of aconitase gene loci in Triticeae species. Theor Appl Genet 74:261–268 Chhuneja P, Kaur S, Goel RK, Aghaee-Sarbarzeh M, Dhaliwal HS (2007) Introgression of leaf rust and stripe rust resistance genes from Aegilops umbellulata to hexaploid wheat through induced homoeologous pairing. In: Buck HT, Nisi JE, Salomon N (eds) Wheat production in stressed environments. Springer, Doerdrecht, Netherlands, pp 83–90 Chhuneja P, Kaur S, Goel RK, Aghaee-Sarbarzeh M, Prashar M, Dhaliwal HS (2008a) Transfer of leaf rust and stripe rust resistance from Aegilops umbellulata Zhuk. to bread wheat (Triticum aestivum L.). Genet Resour Crop Evol 55:849–859 Chhuneja P, Kaur A, Kaur S, Dhaliwal HS, Singh K (2008b) A novel leaf rust resistance gene transferred from Aegilops caudata L. to Triticum aestivum L. maps on chromosome 5D. In: Poster exhibited at 11th international wheat genetics symposium, Sydney, Australia Claesson L, Kotimaki M, von Bothmer R (1990) Crossability and chromosome pairing in some interspecific Triticum hybrids. Hereditas 112:49–55 Cockram J, Jones H, Leigh FJ, O’Sullivan D, Powell W, Laurie DA, Greenland AJ (2007) Control of flowering time in temperate cereals: genes, domestication, and sustainable productivity. J Exp Bot 58:1231–1244 Conner RL, Thomas JB, Whelan EDP (1991) Comparison of mite resistance for control of wheat streak mosaic. Crop Sci 31:315–318 Cox TS, Sears RG, Gill BS (1992) Registration of KS90WGRC10 leaf rust-resistant hard red winter wheat germplasm. Crop Sci 32:506 Cox TS, Hatchett JH (1994) Hessian fly-resistance gene H26 transferred from Triticum tauschii to common wheat. Crop Sci 34:958–960 Cox TS, Raupp WJ, Gill BS (1994) Leaf rust-resistance genes Lr41, Lr42, and Lr43 transferred from Triticum tauschii to common wheat. Crop Sci 34:339–343 Damania AB, Altunji H, Dhaliwal HS (1992) Evaluation of Aegilops spp. for drought and frost tolerance. Genetics Research Unit Annual Report 1992, ICARDA, Aleppo, Syria, pp 45–46 Damania AB (1994) In situ conservation of biodiversity of wild progenitors of cereal crops in the near east. Biodivers Lett 2:56–60 Danyluk J, Kane NA, Breton G, Limin AE, Fowler B, Sarhan F (2003) TaVRT-1, a putative transcription factor associated with vegetative to reproductive transition in cereals. Plant Physiol 132:1849–1860 Davis PH (1985) Aegilops L. In: Davis PH (ed) Flora of Turkey, vol 9. Edinburgh University Press, Edinburgh, pp 233–245 De Candolle A (1883) (en fait, octobre 1882) Origine des Plantes Cultivées. Germer Baillière, Paris, France De Vries AP (1971) Flowering biology of wheat, particularly in view of hybrid seed production – a review. Euphytica 20:152–170 Delibes A, Lopez-Brafia I, Mena M, Garcia-Olmedo F (1987) Genetic transfer of resistance to powdery mildew and of an associated biochemical marker from Aegilops ventricosa to hexaploid wheat. Theor Appl Genet 73:605–608 1 Aegilops Delibes A, Romero D, Aguaded S, Duce A, Mena M, LopezBrana I, Andres M-F, Martin-Sanchez JA, Garcia-Olmedo F (1993) Resistance to the cereal cyst nematode (Heterodera avenae Woll.) transferred from the wild grass Aegilops ventricosa to hexaploid wheat by a “stepping-stone” procedure. Theor Appl Genet 87:402–408 Delibes A, Del Moral J, Martin-Sanchez JA, Mejias A, Gallego M, Casado D, Sin E, López-Brana I (1997) Hessian flyresistance gene transferred from chromosome 4Mv of Aegilops ventricosa to Triticum aestivum. Theor Appl Genet 94:858–864 Dhaliwal HS, Friebe B, Gill KS, Gill BS (1990) Cytogenetic identification of Aegilops squarrosa chromosome additions in durum wheat. Theor Appl Genet 79:769–774 Dhaliwal HS, Harjit-Singh WM (2002) Transfer of rust resistance from Aegilops ovata into bread wheat (Triticum aestivum L.) and molecular characterisation of resistant derivatives. Euphytica 126:153–159 Dinev NS, Netcheva V (1995) Plant mineral composition and tolerance to low pH in species of tribe Triticeae. Soil Sci Plant Anal 26:223–235 Dondlinger PT (1916) The book of wheat, an economic history and practical manual of the wheat industry. Orange Judd Co, Kegan Paul, Trubner & Co, New York, USA Donini PR, Koebner RMD, Ceoloni C (1995) Cytogenetic and molecular mapping of the wheat-Aegilops longissima chromatin breakpoints in powdery mildew-resistant introgression lines. Theor Appl Genet 91:738–743 Dorofeev VF, Filatenko AA, Migushova EF, Udaczin RA, Jakubziner MM (1979) Wheat. Vol 1. In: Dorofeev VF, Korovina ON (eds) Flora of cultivated plants. Leningrad, Russia Dosba F, Doussinault G, Rivoal R (1978) Extraction, identification and utilization of the addition lines T. aestivum– Ae. ventricosa. In: Ramanujam S (ed) Proceedings of the 5th international wheat genetics symposium. Indian Society of Genetics and Plant Breeding, New Delhi, India, pp 332–337 Dosba F (1982) Les lignées d’addition blé – Aegilops ventricosa. III. Extraction et identification des lignées sur cytoplasme Aegilops ventricosa. Agronomie 2:469–478 Doussinault G, Delibes A, Sanchez-Monge R, Garcia-Olmedo F (1983) Transfer of a dominant gene for resistance to eyespot disease from a wild grass to hexaploid wheat. Nature 303:698–700 Dover GA (1973) The genetics and interactions of ‘A’ and ‘B’ chromosomes controlling meiotic chromosome pairing in the Triticeae. In: Sears ER, Sears LMS (eds) Proceedings of the 4th international wheat genetics symposium. University of Missouri, Columbia, USA, p 653667 Driscoll CJ (1974) Wheat–Triticum kotschyi (Aegilops variabilis) (2n ¼ 28) addition lines. EWAC Newsl 4:60 Driscoll CJ, Bielig LM, Darvey NL (1979) Analysis of frequencies of chromosome configurations in wheat and wheat hybrids. Genetics 91:755–767 Dubcovsky J, Lukaszewski AJ, Echaide M, Antonelli EF, Porter DR (1998) Molecular characterization of two Triticum speltoides interstitial translocations carrying leaf rust and greenbug resistance genes. Crop Sci 38:1655–1660 Dubcovsky J, Chen C, Yan L (2005) Molecular characterization of the allelic variation at the VRN-H2 vernalization locus in barley. Mol Breed 15:395–407 63 Dubcovsky J, Loukoianov A, Fu D, Valarik M, Sanchez A, Yan L (2006) Effect of photoperiod on the regulation of wheat vernalization genes VRN1 and VRN2. Plant Mol Biol 60: 469–480 Dubcovsky J, Dvorak J (2007) Genome plasticity a key factor in the success of polyploid wheat under domestication. Science 316:1862–1866 Dunford RP, Griffiths S, Christodoulou V, Laurie DA (2005) Characterisation of a barley (Hordeum vulgare L.) homologue of the Arabidopsis flowering time regulator GIGANTEA. Theor Appl Genet 110:925–931 Dvorak J (1976) The relationship between the genome of Triticum urartu and the A and B genomes of Triticum aestivum. Can J Genet Cytol 18:371–377 Dvorak J (1977) Transfer of leaf rust resistance from Aegilops speltoides to Triticum aestivum. Can J Genet Cytol 19: 133–141 Dvorak J, Lassner MW, Kota RS, Chen KC (1984) The distribution of the ribosomal RNA genes in the Triticum speltoides and Elytrigia elongata genomes. Can J Genet Cytol 26:628–632 Dvorak J, McGuire PE, Cassidi B (1988) Apparent sources of the A genomes of wheat inferred from polymorphism in abundance and restriction fragment length of repeated sequences. Genome 30:680–689 Dvorak J, Knott DR (1990) Location of a Triticum speltoides chromosome segment conferring resistance to leaf rust in Triticum aestivum. Genome 33:892–897 Dvorak J, Zhang HB (1990) Variation in repeated nucleotide sequences sheds light on the phylogeny of the wheat B and G genomes. Proc Natl Acad Sci USA 87:9640–9644 Dvorak J, Zhang HB (1992) Application of molecular tools for study of the phylogeny of diploid and polyploidy taxa in Triticeae. Hereditas 116:37–42 Dvorak J, Diterlizzi P, Zhang H-B, Resta P (1993) The evolution of polyploid wheats: identification of the A genome donor species. Genome 36:21–31 Dvorak J, Luo MC, Yang ZL (1998a) Genetic evidence on the origin of Triticum aestivum L. In: Damania AB, Valkoun J, Willcox G, Qualset CO (eds) The origins of agriculture and crop domestication. Proceedings of Harlan symposium. ICARDA, Aleppo, Syria, pp 235–251 Dvorak J, Luo MC, Yang ZL, Zhang HB (1998b) The structure of the Aegilops tauschii genepool and the evolution of hexaploid wheat. Theor Appl Genet 67:657–670 Dvorak J, Akhunov E (2005) Tempos of gene locus deletions and duplications and their relationship to recombination rate during diploid and polyploid evolution in the AegilopsTriticum alliance. Genetics 17:323–332 Dvorak J, Deal KR, Luo MC (2006) Discovery and mapping of wheat Ph1 suppressors. Genetics 174:17–27 Dyck PL, Kerber ER (1970) Inheritance in hexaploid wheat of adult-plant leaf rust resistance derived from Aegilops squarrosa. Can J Genet Cytol 13:480–483 Eastwood RF, Lagudah ES, Halloran GM, Brown JS, Kollmorgan JF, Appels R (1993) Resistance to cereal cyst nematode in Triticum tauschii. In: Imrie BC, Hacker JB (eds) Focussed plant improvement: towards responsible and sustainable agriculture, vol 2. Proceedings of 10th Australian plant breeding conference, Gold Coast, pp 7–18 64 € Eig A (1929) Monographisch-kritische Ubersicht der Gattung Aegilops. Feddes Repertorium Specierum novarum regni vegetabilis Beih 55:1–228 Eilam T, Anikster Y, Millet E, Manisterski J, Sagi-Assif O, Feldman M (2007) Genome size and genome evolution in diploid Triticeae species. Genome 50:1029–1037 Eilam T, Anikster Y, Millet E, Manisterski J, Feldman M (2008) Nuclear DNA amount and genome downsizing in natural and synthetic allopolyploids of the genera Aegilops and Triticum. Genome 51:616–627 El Bouhssini M, Nachit MM, Valkoun J, Abdalla O, Rihawi F (2008) Sources of resistance to Hessian fly (Diptera: Cecidomyiidae) in Syria identified among Aegilops species and synthetic derived bread wheat lines. Genet Resour Crop Evol 55:1215–1219 Ellstrand NC, Prentıce HC, Hancock JF (1999) Gene flow and introgression from domesticated plants into their wild relatives. Annu Rev Ecol Syst 30:539–563 Endo TR, Tsunewaki K (1975) Sterility of common wheat with Aegilops triuncialis cytoplasm. J Hered 66:13–18 Endo TR, Katayama Y (1978) Finding of a selectively retained chromosome of Aegilops caudata L. in common wheat. Wheat Info Serv 48:32–35 Endo TR (1979) Selective gametocidal action of a chromosome of Aegilops cylindrica in a cultivar of common wheat. Wheat Info Serv 50:24–28 Endo TR (1985) Two types of gametocidal chromosomes of Ae. sharonensis and Ae. longissima. Jpn J Genet 60:125–135 Endo TR (1988) Chromosome mutations induced by gametocidal chromosomes in common wheat. In: Millet TE, Koebner RMD (eds) Proceedings of the 7th international wheat genetics symposium, Cambridge, UK, pp 259–265 Endo TR (1990) Gametocidal chromosomes and their induction of chromosome mutations in wheat. Jpn J Genet 65:135–152 Endo TR, Gill BS (1996) The deletion stocks of common wheat. J Hered 87:295–307 Fandrich L, Mallory-Smith CA, Zemetra RS, Hansen JL (2008) Vernalization responses of jointed goatgrass (Aegilops cylindrica), wheat, and wheat by jointed goatgrass hybrid plants. Weed Sci 56:534–542 Faris J, Sirikhachornkit A, Haselkorn R, Gill B, Gornicki P (2001) Chromosome mapping and phylogenetic analysis of the cytosolic acetyl-CoA carboxylase loci in wheat. Mol Biol Evol 18:1720–1733 Faris JD, Steven SX, Xiwen C, Timothy LF, Yue J (2008) Molecular and cytogenetic characterization of a durum Wheat-Aegilops speltoides chromosome translocation conferring resistance to stem rust. Chrom Res 16:1097–1105 Farooq S, Niazi MLK, Iqbal N, Shah TM (1989) Salt tolerance potential of wild resources of the tribe Triticeae. II. Screening of species of genus Aegilops. Plant Soil 119:255–260 Farooq S, Azam FE (2001) Co-existence of salt and drought tolerance in Triticeae. Hereditas 135:205–210 Faure S, Higgins J, Turner A, Laurie DA (2007) The flowering locus T-like gene family in barley (Hordeum vulgare). Genetics 176:599–609 Fedak G, Cao W, Han F, Savard M, Gilbert J, Xue A (2004) Germplasm enhancement for FHB resistance in spring wheat through alien introgression. In: Canty SM, Boring T, Versdahl TK, Wardwell J, Ward RW (eds) Proceedings of the 2nd international symposium on fusarium head blight. B. Kilian et al. Michigan State University, Orlando, East Lansing, MI, USA, pp 56–57 Feldman M (1975) Alien addition lines of common wheat containing Triticum aestivum chromosomes. Proceedings of 12th international botanical congress. Leningrad, USSR, p 506 Feldman M (1978) New evidence on the origin of the B genome of wheat. In: Ramanujam S (ed) Proceedings of 5th international wheat genetics symposium, vol 1. Indian Society of Genetics and Plant Breeding, New Delhi, India, pp 120–132 Feldman M (1983) Gene transfer from wild species into cultivated plants. Acta Biol Yugoslav Genet 15:145–161 Feldman M (1988) Cytogenetic and molecular approaches to alien gene transfer in wheat. In: Miller TE, Koebner RMD (eds) Proceedings of the 7th international wheat genetics symposium, Cambridge, UK, pp 23–32 Feldman M, Sears ER (1981) The wild gene resources of wheat. Sci Am 244:102–112 Fernandez-Calvin B, Orellana J (1991) Metaphase I bound arms frequency and genome analysis in wheat-Aegilops hybrids. 1. Ae. variabilis-wheat and Ae. kotschyi-wheat hybrids with low and high homoeologous pairing. Theor Appl Genet 83:264–272 Flinn MF, Smith CM, Reese JC, Gill BS (2001) Categories of resistance to greenbug (Homoptera: Aphididae) biotype I in Aegilops tauschii germplasm. J Econ Entomol 94:558–563 Friebe B, Mukai Y, Dhaliwal HS, Martin TJ, Gill BS (1991) Identification of alien chromatin specifying resistance to wheat streak mosaic virus and greenbug in wheat germplasm by C-banding and in situ hybridization. Theor Appl Genet 81:381–389 Friebe B, Schubert V, Bl€ uthner WD, Hammer K (1992) C-banding pattern and polymorphism of Aegilops caudata and chromosomal constitutions of the amphiploid T. aestivum – Ae. caudata and six derived chromosome addition lines. Theor Appl Genet 83:589–596 Friebe B, Tuleen N, Jiang J, Gill BS (1993) Standard karyotype of Triticum longissimum and its cytogenetic relationship with T. aestivum. Genome 36:731–742 Friebe B, Tuleen NA, Gill BS (1995a) Standard karyotype of Triticum searsii and its relationship with other S-genome species and common wheat. Theor Appl Genet 91:248–254 Friebe B, Jiang J, Tuleen N, Gill BS (1995b) Standard karyotype of Triticum umbellulatum and the characterization of derived chromosome addition and translocation lines in common wheat. Theor Appl Genet 90:150–156 Friebe B, Tuleen NA, Badaeva ED, Gill BS (1996a) Cytogenetic identification of Triticum peregrinum chromosomes added to common wheat. Genome 39:272–276 Friebe B, Jiang J, Raupp WJ, McIntosh RA, Gill BS (1996b) Characterization of wheat alien translocations conferring resistance to diseases and pests: current status. Euphytica 91:59–87 Friebe B, Badaeva ED, Hammer K, Gill B (1996c) Standard karyotypes of Aegilops uniaristata, Ae. mutica, Ae. comosa subspecies comosa and heldreichii (Poaceae). Plant Syst Evol 202:199–210 Friebe B, Tuleen NA, Gill BS (1999) Development and identification of a complete set of Triticum aestivum– Aegilops geniculata chromosome addition lines. Genome 42:374–380 1 Aegilops Friebe B, Qi LL, Nasuda A, Zhang P, Tuleen NA, Gill BS (2000) Development of a complete set of Triticum aestivum– Aegilops speltoides chromosome addition lines. Theor Appl Genet 101:51–58 Friebe B, Zhang P, Nasuda S, Gill BS (2003) Characterization of a knock-out mutation at the Gc2 locus in wheat. Chromosoma 111:509–517 Fu D, Sz€ucs P, Yan L, Helguera M, Skinner JS, von Zitzewitz J, Hayes PM, Dubcovsky J (2005) Large deletions within the first intron in VRN1 are associated with spring growth habit in barley and wheat. Mol Gen Genom 273:54–65 Fu YB, Somers DJ (2009) Genome-wide reduction of genetic diversity in wheat breeding. Crop Sci 49:161–198 Galili S, Avivi Y, Millet E, Feldman M (2000) RFLP-based analysis of three RbcS subfamilies in diploid and polyploidy species of wheat. Mol Gen Genet 263:674–680 Gandhi HT, Vales MI, Watson CJW, Mallory-Smith CA, Mori N, Reman M, Zemetra RS, Riera-Lizarazu O (2005) Chloroplast and nuclear microsatellite analysis of Aegilops cylindrica. Theor Appl Genet 111:561–572 Garcia-Olmedo F, Delibes A, Sanchez-Monge R (1984) Transfer of resistance to eyespot disease from Aegilops ventricosa to wheat. In: Breeding for disease resistance and oat breeding. Proceedings of EUCARPIA Cereal Section Meeting, Weihenstephan, Germany Gautier M, Aleman ME, Guirao A, Marion D, Joudrier P (1994) Triticum aestivum puroindolines, two basic cystine-rich seed proteins: cDNA sequence analysis and developmental gene expression. Plant Mol Biol 25:43–57 Gautier MF, Cosson P, Guirao A, Alary R, Joudrier P (2000) Puroindoline genes are highly conserved in diploid ancestor wheats and related species but absent in tetraploid Triticum species. Plant Sci 153:81–91 Gianibelli MC, Gupta RB, Lafiandra D, Margiotta B, MacRitchie F (2001) Polymorphism of high Mr glutenin subunits in Triticum tauschii: characterization by chromatography and electrophoretic methods. J Cereal Sci 33: 39–52 Gianibelli MC, Lagudah ES, Wrigley CW, MacRitchie F (2002a) Biochemical and genetic characterization of a monomeric storage protein (T1) with an unusually high molecular weight in Triticum tauschii. Theor Appl Genet 104:497–504 Gianibelli MC, Wrigley CW, MacRitchie F (2002b) Polymorphism of low Mr glutenin subunits in Triticum tauschii. J Cereal Sci 35:277–286 Gielly L, Taberlet P (1994) The use of chloroplast DNA to resolve plant phylogenies: noncoding versus rbcL sequences. Mol Biol Evol 11:769–777 Giles RJ, Brown TA (2006) GluDy allele variations in Aegilops tauschii and Triticum aestivum: implications for the origins of hexaploid wheats. Theor Appl Genet 112:1563–1572 Gill BS, Kimber G (1974) Giemsa C-banding and the evolution of wheat. Proc Natl Acad Sci USA 71:40864090 Gill BS, Chen PD (1987) Role of cytoplasm-specific introgression in the evolution of the polyploid wheats. Proc Natl Acad Sci USA 84:6800–6804 Gill BS, Hatchett JH, Raupp WJ (1987) Chromosomal mapping of Hessian fly-resistance gene H13 in the D genome of wheat. J Hered 78(2):97–100 Gill BS, Friebe B, Endo TR (1991a) Standard karyotype and nomenclature system for description of chromosome bands 65 and structural aberrations in wheat (Triticum aestivum). Genome 34:830–839 Gill KS, Lubbers EL, Gill BS, Raupp WJ, Cox TS (1991b) A genetic linkage map of Triticum tauschii (DD) and its relationship to the D-genome of bread wheat (AABBDD). Genome 14:362–374 Gill KS, Hassawi D, Raupp WJ, Fritz AK, Gill BS et al. (1992) An updated genetic linkage map of Triticum tauschii, the D-genome progenitor of wheat. In: Gill BS, Raupp WJ, Corke H (eds) Progress in genome mapping of wheat and related species. Proceedings of the 2nd international Triticeae mapping initiative, 1991, Manhattan, KS, USA. Report No. 10, University of California Genetic Resources Conservation Program, Davis, CA, 82p Giorgi B (1983) Origin, behaviour and utilization of a ph1 mutant of durum wheat, Triticum turgidum L. var. durum. In: Sakamoto S (ed) Proceedings of the 6th international wheat genetics symposium. Kyoto University, Kyoto, Japan, pp 1033–1040 Giroux M, Morris CG (1998) Wheat grain hardness results from highly conserved mutations in the friabilin components puroindoline a and b. Proc Natl Acad Sci USA 95:6262–6266 Giroux MJ, Talbert L, Habernicht DK, Lanning S, Hempill A, Martin JM (2000) Association of puroindoline sequence type and grain hardness in hard red spring wheat. Crop Sci 40:370–374 Godron DA (1854) De la fécondation naturelle et artificielle des Aegilops par le Triticum. Ann Sci Nat Sér 3:215–222 Gold J, Harder D, Townley-Smith F, Aung T, Procunier J (1999) Development of a molecular marker for rust resistance genes Sr39 and Lr35 in wheat breeding lines. Electron J Biotechnol 2(1):35–40 Goldberg SM, Johnson J, Busam D, Feldblyum T, Ferriera S, Friedman R, Halpern A, Khouri H, Kravitz SA, Lauro FM, Li K, Rogers YH, Strausberg R, Sutton G, Tallon L, Thomas T, Venter E, Frazier M, Venter JC (2006) A Sanger/pyrosequencing hybrid approach for the generation of high-quality draft assemblies of marine microbial genomes. Proc Natl Acad Sci USA 103:11240–11245 Gollan P, Smith K, Bhave M (2007) Gsp-1 genes comprise a multigene family in wheat that exhibits a unique combination of sequence diversity yet conservation. J Cereal Sci 45:184–198 Golovnina KA, Glushkov SA, Blinov AG, Mayorov VI, Adkison LR, Goncharov NP (2007) Molecular phylogeny of the genus Triticum L. Plant Syst Evol 264:195–216 Goryunova SV, Kochieva EZ, Chikida NN, Pukhalskyi VA (2004) Phylogenetic relationships and intraspecific variation of D-genome Aegilops L. as revealed by RAPD analysis. Russ J Genet 40:515–523 Goryunova SV, Chikida NN, Gori M, Kochieva EZ (2005) Analysis of nucleotide sequence polymorphism of internal transcribed spacers of ribosomal genes in diploid Aegilops (L.) species. Mol Biol 39:173–176 Govindaraju DR (1988) A note on the relationship between outcrossing rate and gene flow in plants. Heredity 61:401–404 Griffiths S, Dunford RP, Coupland G, Laurie DA (2003) The evolution of CONSTANS-like gene families in barley, rice and Arabidopsis. Plant Physiol 131:1855–1867 Groenewald JZ, Marais AS, Marais GF (2003) Amplified fragment length polymorphism-derived microsatellite sequence 66 linked to the Pch1 and Ep-D1 loci in common wheat. Plant Breed 122:83–85 Gu YQ, Coleman-Derr D, Kong X, Anderson OD (2004) Rapid genome evolution revealed by comparative sequence analysis of orthologous regions from four Triticeae genomes. Plant Physiol 135:459–470 Gu YQ, Salse J, Coleman-Derr D, Dupin A, Crossman C, Lazo GR, Huo N, Belcram H, Ravel C, Charmet G, Charles M, Anderson OD, Chalhoub B (2006) Types and rates of sequence evolution at the high-molecular weight glutenin locus in hexaploid wheat and its ancestral genomes. Genetics 174:1493–1504 Guadagnolo R, Savova-Bianchi D, Felber F (2001a) Gene flow from wheat (Triticum aestivum L.) to jointed goatgrass (Aegilops cylindrica Host), as revealed by RAPD and microsatellite markers. Theor Appl Genet 103:1–8 Guadagnolo R, Savova-Bianchi D, Felber F (2001b) Specific genetic markers for wheat, spelt, and four wild relatives: comparison of isozymes, RAPDs, and wheat microsatellites. Genome 44:610–621 Gupta RB, Shepherd KW (1990) Two-step one-dimensional SDS-PAGE analysis of LMW subunits of glutelin. 2. Genetic control of the subunits in species related to wheat. Theor Appl Genet 80:183–187 Haider N, Nabulsi I (2008) Identification of Aegilops L. species and Triticum aestivum L. based on chloroplast DNA. Genet Resour Crop Evol 55:537–549 Hammer K (1978) Bl€utenökologische Merkmale und Reproduktionssystem von Aegilops tauschii Coss. (syn. Ae. squarrosa L.). Kulturpflanze 26:271–282 Hammer K (1980a) Vorarbeiten zur monographischen Darstellung von Wildpflanzensortimenten: Aegilops L. Kulturpflanze 28:33–180 Hammer K (1980b) Zur Taxonomie und Nomenklatur der Gattung Aegilops L. Feddes Rep 91:225–258 Hammer K (1982) A key for determination of Aegilops species. MPGR News, Bari 1(2):9–13 Hammer K (1985) Vorarbeiten zur monographischen Darstellung von Wildpflanzensortimenten: Aegilops L. – Resistenzuntersuchungen. Kulturpflanze 33:123–131 Hammer K (1987) Resistenzmerkmale und Reproduktionssystem als Indikatoren f€ ur evolution€are Tendenzen in der Gattung Aegilops L. Biol Zbl 106:273–282 Hammer K, Laghetti G (2005) Genetic erosion – examples from Italy. Genet Resour Crop Evol 52:629–634 Hammer K, Pistrick K, Filatenko AA (2011) Taxonomic remarks on Triticum L. and x Triticosecale Wittm. Hamrick JL, Linhart YB, Mitton JB (1979) Relationships between life history characteristics and electrophoretically detectable genetic variation in plants. Annu Rev Ecol Syst 10:173–200 Hanelt P (2001) Triticum L. In: Hanelt P, Institute of Plant Genetics and Crop Plant Research (eds) Mansfeld’s encyclopedia of agricultural and horticultural crops, vol 5. Springer, Heidelberg, pp 2565–2591 Harlan JR (1992) The gene pool system. In: Crops and man, 2nd edn. American Society for Agronomy and Crop Science Society of America, Madison, Wisconsin, USA, pp 106–107 Hart GE, Tuleen NA (1983) Introduction and characterization of alien genetic material. In: Tanksley SD, Orton TJ (eds) B. Kilian et al. Isozymes in plant genetics and breeding. Elsevier, Amsterdam, Netherlands, pp 103–120 Haudry A, Cenci A, Ravel C, Bataillon T, Brunel D, Ponce C, Hochu I, Poirier S, Santoni S, Glémin S, David J (2007) Grinding up wheat: a massive loss of nucleotide diversity since domestication. Mol Biol Evol 24:1506–1517 Hawkes JG, Maxted N, Ford-Lloyd BV (2000) The ex situ conservation of plant genetic resources. Kluwer, Dordrecht, Netherlands Hedge SG, Valkoun J, Waines JG (2002) Genetic diversity in wild and weedy Aegilops, Amblyopyrum and Secale species – preliminary survey. Crop Sci 42:608–614 Hedge SG, Waines JG (2004) Hybridization and introgression between bread wheat and wild and weedy relatives in North America. Crop Sci 44:1145–1155 Helguera M, Khan IA, Kolmer J, Lijavetzky D, Zhong-Qi L, Dubcovsky J (2003) PCR assays for the Lr37-Yr17-Sr38 cluster of rust resistance genes and their use to develop isogenic hard red spring wheat lines. Crop Sci 43:1839–1847 Helguera M, Vanzetti L, Soria M, Khan IA, Kolmer J, Dubcovsky J (2005) PCR markers for Triticum speltoides leaf rust resistance gene Lr51 and their use to develop isogenic hard red spring wheat lines. Crop Sci 45:728–734 Heun M, Sch€afer-Pregl R, Klawan D, Castagna R, Accerbi M, Borghi B, Salamini F (1997) Site of einkorn wheat domestication identified by DNA fingerprinting. Science 278:1312–1314 Hiebert C, Thomas J, Somers D, McCallum B, Fox S (2007) Microsatellite mapping of adult-plant leaf rust resistance gene Lr22a in wheat. Theor Appl Genet 115:877–884 Hodgkin T, Adham YJ, Powel KS (1992) A preliminary survey of wild Triticum and Aegilops species in the world’s genebanks. Hereditas 116:155–162 Hollenhorst MM, Joppa LR (1983) Chromosomal location of genes for resistance to greenbug in ‘Largo’ and ‘Amigo’ wheats. Crop Sci 23:91–93 Holubec V, Havlı́čková A (1994) Interspecific differences in cereal aphid infestation of 20 Aegilops species. Genet a Šlecht 30:81–87 Horovitz A, Feldman M (eds) (1991) International workshop on the dynamic in situ conservation of wild relatives of major cultivated plants. Isr J Bot 40:509–519 Hsam SLK, Lapochkina IF, Zeller FJ (2003) Chromosomal location of genes for resistance to powdery mildew in common wheat (Triticum aestivum L. em. Thell.). 8. Gene Pm32 in a wheat-Aegilops speltoides translocation line. Euphytica 133:367–370 Huang L, Gill BS (2001) An RGA-like marker detects all known Lr21 leaf rust resistance gene family members in Aegilops tauschii and wheat. Theor Appl Genet 103:1007–1013 Huang S, Sirikhachornkit A, Su X, Faris J, Gill B, Haselkorn R, Gornicki P (2002) Genes encoding plastid acetyl-CoA carboxylase and 3-phosphoglycerate kinase of the Triticum/ Aegilops complex and the evolutionary history of polyploidy wheat. Proc Natl Acad Sci USA 99:8133–8138 Huang L, Brooks SA, Li W, Fellers JP, Trick HN, Gill BS (2003) Map-based cloning of leaf rust resistance gene Lr21 from the large and polyploid genome of bread wheat. Genetics 164:655–664 Hucl P (1996) Out-crossing rates for 10 Canadian spring wheat cultivars. Can J Plant Sci 76:423–427 1 Aegilops Hueros G, Gonzalez JM, Sanz JC, Ferrer E (1991) Gliadin gene location and C-banding identification of Aegilops longissima chromosomes added to wheat. Genome 34:236–240 Huguet-Robert V, Dedryver F, Roder MS, Korzun V, Abelard P, Tanguy AM, Jaudeau B, Jahier J (2001) Isolation of a chromosomally engineered durum wheat line carrying the Aegilops ventricosa Pch1 gene for resistance to eyespot. Genome 44:345–349 Hussien T, Bowden RL, Gill BS, Cox TS (1997) Chromosomal location of leaf rust resistance gene Lr43 from Aegilops tauschii in common wheat. Crop Sci 37:1764–1766 Iqbal N, Reader SM, Caligari PDS, Miller TE (2000) Characterization of Aegilops uniaristata chromosomes by comparative DNA marker analysis and repetitive DNA sequence in situ hybridization. Theor Appl Genet 102:1173–1179 Jaaska V (1981) Aspartate aminotransferase and alcohol dehydrogenase isozymes: Intraspecific differentiation in Aegilops tauschii and the origin of the D genome polyploids in the wheat group. Plant Syst Evol 137:259–273 Jaaska V (1995) Isoenzymes in the evaluation of germplasm diversity in wild diploid relatives of cultivated wheat. In: Damania AB (ed) Biodiversity and wheat improvement. Wiley, Chichester, UK, pp 247–257 Jahier J, Doussinault G, Dosba F, Bourgeois F (1978) Monosomic analysis of resistance to eyespot in the variety “Roazon”. In: Ramanujam S (ed) Proceedings of the 5th international wheat genetics symposium. Indian Society of Genetics and Plant Breeding, New Delhi, India, pp 437–440 Jahier J, Tanguy AM, Abelard P, Rivoal R (1996) Utilization of deletions to localize a gene for resistance to the cereal cyst nematode, Heterodera avenue, on an Aegilops ventricosa chromosome. Plant Breed 115:282–284 Jahier J, Rivoal R, Yu MQ, Abélard P, Tanguy AM, Barloy D (1998) Transfer of genes for resistance to cereal cyst nematode from Aegilops variabilis Eig to wheat. J Genet Breed 52:253–257 Jahier J, Abelard P, Tanguy AM, Dedryver F, Rivoal R, Khatkar S, Bariana HS (2001) The Aegilops ventricosa segment on chromosome 2AS of the wheat cultivar ’VPM1’ carries the cereal cyst nematode resistance gene Cre5. Plant Breed 120:125–128 Jarvis CE (1992) Seventy-two proposals for the conservation of types of selected Linnaean generic names, the report of subcommittee 3C on the lectotypification of Linnaean generic names. Taxon 41:555–556 Jia JZ (1996) RFLP-based maps of the homoeologous group-6 chromosomes of wheat and their in the tagging of Pm12, powdery mildew resistance gene transferred from Aegilops speltoides to wheat. Theor Appl Genet 92:559–565 Jiang J, Gill BS (1993) Sequential chromosome banding and in situ hybridization. Genome 36:792–795 Jiang J, Gill BS (1994) Nonisotopic in situ hybridization and plant genome mapping: the first 10 years. Genome 37:717–725 Jiang C, Pei Y, Zhang Y, Li X, Yao D, Yan Y, Ma W, Hasam SLK, Zeller FJ (2008) Molecular cloning and characterization of four novel LMW glutenin subunit genes from Aegilops longissima, Triticum dicoccoides and T. zhukovskyi. Hereditas 145:92–98 Johnson BL (1975) Identification of the apparent B-genome donor of wheat. Can J Genet Cytol 17:21–39 67 Johnson BL, Dhaliwal HS (1976) Reproductive isolation of Triticum boeoticum and Triticum urartu and the origin of the tetraploid wheats. Am J Bot 63:1088–1094 Jones H, Leigh FJ, Mackay I, Bower MA, Smith LMJ, Charles MP, Jones G, Jones MK, Brown TA, Powell W (2008) Population-based resequencing reveals that the flowering time adaptation of cultivated barley originated east of the Fertile Crescent. Mol Biol Evol 25:2211–2219 Joppa LR, MacNeal FH, Berg MA (1968) Pollen production and pollen shedding of hard red spring (Triticum aestivum L. em. Thell.) and durum (T. durum Desf.) wheats. Crop Sci 8:487–490 Joppa LR, Williams ND (1988) Langdon durum disomic substitution lines and aneuploid analysis in tetraploid wheat. Genome 30:222–228 Kadosumi S, Kawahara T, Sasanuma T (2005) Multiple origins of U genome in two UM genome tetraploid Aegilops species, Ae. columnaris and Ae. triaristata, revealed based on the polymorphism of a genome-specific PCR fragment. Gene Genet Syst 80:105–111 Kan Y, Wan Y, Beaudoin F, Leader DJ, Edwards K, Poole R, Wang D, Mitchell RAC, Shewry PR (2006) Transcriptome analysis reveals differentially expressed storage protein transcripts in seeds of Aegilops and wheat. J Cereal Sci 44:75–85 Kane NA, Danyluk J, Tardif G, Ouellet F, Laliberte J, Limin AE, Fowler DB, Sarhan F (2005) TaVRT-2, a member of the StMADS-11 clade of flowering repressors, is regulated by vernalization and photoperiod in wheat. Plant Physiol 138:2354–2363 Kaplan D (2008) A designated nature reserve for in situ conservation of wild emmer wheat (Triticum dicoccoides (Körn.) Aaronsohn) in northern Israel. In: Maxted N, Ford-Lloyd BV, Kell SP, Iriondo J, Dulloo E, Turok J (eds) Crop wild relative conservation and use. CAB International, Wallingford, UK, pp 389–393 Karagöz A (1998) In situ conservation of plant genetic resources in the Ceylanpinar State Farm. In: Zencirci N, Kaya Z, Anikster Y, Adams WT (eds) Proceedings of the international symposium on in situ conservation of plant diversity. Central Research Institute for Field Crops, Ankara, Turkey, pp 87–91 Karsai I, Sz€ ucs P, Meszaros K, Filichkina T, Hayes PM, Skinner JS, Lang L, Bedö Z (2005) The Vrn-H2 locus is a major determinant of flowering time in a facultative winter growth habit barley (Hordeum vulgare L.) mapping population. Theor Appl Genet 110:1458–1466 Kawahara T (2002) Morphological and isozyme variation in genebank accessions of Aegilops umbellulata Zhuk., a wild relative of wheat. Genet Resour Crop Evol 49:89–94 Kellogg EA, Appels R, Mason-Gamer RJ (1996) When genes tell different stories: the diploid genera of Triticeae. Syst Bot 21:321–347 Kerber ER (1964) Wheat: reconstitution of the tetraploid component (AABB) of hexaploids. Science 143:253–255 Kerber ER, Dyck PL (1969) Inheritance in hexaploid wheat of leaf rust resistance and other characters derived from Aegilops squarrosa. Can J Genet Cytol 11:639–647 Kerber ER, Dyck PL (1979) Resistance to stem rust and leaf rust of wheat in Aegilops squarrosa and transfer of a gene for stem rust resistance to hexaploid wheat. In: Ramanujam S (ed) Proceedings of the 5th international wheat genetics 68 symposium. Indian Society of Genetics and Plant Breeding, New Delhi, India, pp 358–364 Kerber ER (1987) Resistance to leaf rust in hexaploid wheat: Lr32 a third gene derived from Triticum tauschii. Crop Sci 27:204–206 Kerber ER, Dyck PL (1990) Transfer to hexaploid wheat of linked genes for adult-plant leaf rust and seedling stem rust resistance from an amphiploid of Aegilops speltoides x Triticum monococcum. Genome 33:530–537 Khan MN, Heyne EG, Arp AL (1973) Pollen distribution and the seedset on Triticum aestivum L. Crop Sci 13:223–226 Khlestkina EK, Salina EA (2001) Genome-specific markers of tetraploid wheats and their putative diploid progenitor species. Plant Breed 120:227–232 Kihara H (1924) Cytologische und genetische Studien bei wichtigen Getreidearten mit besonderer R€ ucksicht auf das Verhalten der Chromosomen und die Sterilit€at in den Bastarden. Mem Coll Sci Univ Kyoto Ser B 1:1–200 Kihara H (1937) Genomanalyse bei Triticum and Aegilops. VII. € €uber die Ergebnisse der Jahre 1934–1936. Kurze Ubersicht Mem Coll Agric Kyoto Imp Univ 41:1–61 Kihara H (1944) Die Entdeckung der DD-Analysatoren beim Weizen. Agric Hort 19:889–890 Kihara H (1951) Substitution of nucleus and its effects on genome manifestation. Cytologia 16:177–193 Kihara H (1954) Considerations on the evolution and distribution of Aegilops species based on the analyser-method. Cytologia19:336–357 Kihara H, Tsunewaki K (1962) Use of an alien cytoplasm as a new method of producing haploids. Jpn J Genet 37:310–313 Kihara H, Yamashita H, Tanaka M (1965) Morphological, physiological, genetical, and cytological studies in Aegilops and Triticum collected in Pakistan, Afghanistan, Iran. Results of the Kyoto University scientific expedition to the Karakoram and Hindukush in 1955. In: Yamashita K (ed) Cultivated plants and their relatives. Kyoto, Japan, pp 4–41 Kilian B, Özkan H, Deusch O, Effgen S, Brandolini A, Kohl J, Martin W, Salamini F (2007a) Independent wheat B and G genome origins in outcrossing Aegilops progenitor haplotypes. Mol Biol Evol 24:217–227 Kilian B, Özkan H, Walther A, Kohl J, Dagan T, Salamini F, Martin W (2007b) Molecular diversity at 18 loci in 321 wild and 92 domesticate lines reveal no reduction of nucleotide diversity during Triticum monococcum (einkorn) domestication: implications for the origin of agriculture. Mol Biol Evol 24:2657–2668 Kilian B, Özkan H, Pozzi C, Salamini F (2009) Domestication of the Triticeae in the Fertile Crescent. In: Feuillet C, Muehlbauer G (eds) Genetics and genomics of the Triticeae. Plant genetics and genomics: crops and models 7. Springer, New York, pp 81–119 Kimber G (1967) The addition of the chromosomes of Aegilops umbellulata to Triticum aestivum var. Chinese Spring. Genet Res (Camb) 9:111–114 Kimber G, Athwal RS (1972) A reassessment of the course of evolution of wheat. Proc Natl Acad Sci USA 69:912–915 Kimber G, Hulse MM (1978) The analysis of chromosome pairing in hybrids and evolution of wheat. In: Ramanujam S (ed) Proceedings of the 5th international wheat genetics symposium. Indian Society of Genetics and Plant Breeding, New Delhi, India, pp 63–72 B. Kilian et al. Kimber G, Abu Bakar M (1979) Wheat hybrid information systems. Cereal Res Commun 7:257–260 Kimber G, Alonso LC, Salle PJ (1981) The analysis of meiosis in hybrids. I. Aneuploid hybrids. Can J Genet Cytol 23: 209–219 Kimber G, Alonso LC (1981) The analysis of meiosis in hybrids. III. Tetraploid hybrids. Can J Genet Cytol 23:235–254 Kimber G, Feldman M (1987) Wild wheat: an introduction, Spl Rep 353. College of Agriculture, University of Missouri, Columbia, USA Kimber G, Sears, ER (1983) Assignment of genome symbols in the Triticeae. In: Proceedings of the sixth international wheat genetics symposium, Kyoto, Japan, pp. 1195–1196. Kimber G, Sears ER (1987) Evolution in the genus Triticum and the origin of cultivated wheat. In: Heyne EG (ed) Wheat and wheat improvement, 2nd edn. American Society of Agronomy, Madison, WI, USA, pp 154–164 Kimber G, Tsunewaki K (1988) Genome symbols and plasma types in the wheat group. In: Miller TE, Koebner RMD (eds) Proceedings of the 7th international wheat symposium, 1987, Cambridge, pp 1209–1211 Kislev ME (1980) Triticum parvicoccum sp. nov., the oldest naked wheat. Isr J Bot 28:95–107 Knobloch IW (1968) A checklist of crosses in the Gramineae. Department of Botany and Plant Pathology, Michigan State University, East Lansing, MI, USA Kn€ upffer H (2009) Triticeae genetic resources in ex situ genebank collections. In: Feuillet C, Muehlbauer G (eds) Genetics and genomics of the Triticeae. Plant genetics and genomics: crops and models 7. Springer, New York, pp 31–79 Koba T, Shimada T (1993) Crossability of common wheat with Aegilops squarrosa. Wheat Inf Serv 77:7–12 Koebner RMD (1987) Genetic control of a novel series of trypsin inhibitors in wheat and its relatives. Biochem Genet 25:591–602 Koebner RMD Miller TE, Snape JW, Law CN (1988) Wheat endopeptidase: genetic control, polymorphism, intrachromosomal gene location and alien variation. Genome 30:186–192 Koebner RMD (1990) Subtilisin inhibitor – a polymorphic protein produced by a gene on the short arms of wheat homoeologous group 1 chromosomes. J Genet Breed 44:49–52 Komatsuda T, Pourkheirandish M, He C, Azhaguvel P, Kanamori H, Perovic D, Stein N, Graner A, Wicker T, Tagiri A, Lundqvist U, Fujimura T, Matsuoka M, Matsumoto T, Yano M (2007) Six-rowed barley originated from a mutation in a homeodomain-leucine zipper I-class homeobox gene. Proc Natl Acad Sci USA 104:1424–1429 Kota RS, Dvorak J (1988) Genomic instability in wheat induced by chromosome 6Bs of Triticum speltoides. Genetics 120:1085–1094 Koti K, Karsai I, Sz€ ucs P, Horvath CS, Meszaros K, Kiss GB, Bedö Z, Hayes PM (2006) Validation of the two-gene epistatic model for vernalization response in a winter x spring barley cross. Euphytica 152:17–24 Krattinger SG, Lagudah ES, Spielmeyer W, Singh RP, HuertaEspino J, McFadden H, Bossolini E, Selter LL, Keller B (2009) A putative ABC transporter confers durable resistance to multiple fungal pathogens in wheat. Science 323:1360–1363 1 Aegilops Kuraparthy V, Chhuneja P, Dhaliwal SH, Kaur S, Bowden RL, Gill BS (2007a) Characterization and mapping of cryptic alien introgression from Aegilops geniculata with new leaf rust and stripe rust resistance genes Lr57 and Yr40 in wheat. Theor Appl Genet 114:1379–1389 Kuraparthy V, Sood S, Chhuneja P, Dhaliwal SH, Kaur S, Bowden RL, Gill BS (2007b) A cryptic wheat-Aegilops triuncialis translocation with leaf rust resistance gene Lr58. Crop Sci 47:1995–2003 Kynast RG, Friebe B, Gill BS (2000) Fate of multicentric and ring chromosomes induced by a new gametocidal factor located on chromosome 4Mg of Aegilops geniculata. Chrom Res 8:133–139 Lagudah ES, Halloran GM (1988) Phylogenetic relationships of Triticum tauschii, the D genome donor of hexaploid wheat 1. Variation in HMW subunits of glutenin and gliadins. Theor Appl Genet 75:592–598 Lange JMC (1860) Pugillus plantarum imprimis hispanicarum, vol 1. Extr Vid Medd Naturh For København, Bianco Luno, Hauniae, Copenhagen Laurie D, Pratchett N, Bezant JH, Snape JW (1995) RFLP mapping of five major genes and eight quantitative traits loci controlling flowering time in a winter x spring barley (Hordeum vulgare) cross. Genome 38:575–585 Lelley T, Stachel M, Grausgruber H, Vollmann J (2000) Analysis of relationships between Aegilops tauschii and the D genome of wheat utilizing microsatellites. Genome 43:661–668 Levy AA, Galili G, Feldman M (1985) The effect of additions of Aegilops longissima chromosomes on grain protein in common wheat. Theor Appl Genet 69:429–435 Li W, Huang L, Gill BS (2008a) Recurrent deletions of puroindoline genes at the grain Hardness locus in four independent lineages of polyploidy wheat. Plant Physiol 146:200–212 Li X, Ma W, Gao L, Zhang Y, Wang A, Ji K, Wang K, Appels R, Yan Y (2008b) A novel chimeric low-molecular-weight glutenin subunit gene from the wild relatives of wheat Aegilops kotschyi and Ae. juvenalis: evolution at the Glu-3 loci. Genetics 180:93–101 Lijavetzky D, Muzzi G, Wicker T, Keller B, Wing R, Dubcovsky J (1999) Construction and characterization of a bacterial artificial chromosome (BAC) library for the A genome of wheat. Genome 42:1176–1182 Lillemo M, Simeone MC, Morris CF (2002) Analysis of puroindoline a and b sequences from T. aestivum cv. ‘Penawawa’ and related diploid taxa. Euphytica 126:321–331 Limin AE, Fowler DB (1981) Cold resistance of some wild relatives of hexaploid wheat. Can J Bot 59:572–573 Liu CJ, Gale MD (1990) Est-7, a set of genes controlling green tissue esterases in wheat and related species. Theor Appl Genet 79:781–784 Liu XM, Gill BS, Chen MS (2005) Hessian fly resistance gene H13 is mapped to a distal cluster of resistance genes in chromosome 6DS of wheat. Theor Appl Genet 111:243–249 Long H, Wei YM, Yan ZH, Baum B, Nevo E, Zheng YL (2005) Classification of wheat low-molecular-weight glutenin subunit genes and its chromosome assignment by developing LMW-GS group-specific primers. Theor Appl Genet 111:1251–1259 Lukaszewski A (1995) Physical distribution of translocation breakpoints in homoeologous recombinants induced by the 69 absence of Ph1 gene in wheat and triticale. Theor Appl Genet 90:714–719 Luo MC, Yang ZL, You FM, Kawahara T, Waines JG, Dvorak J (2007) The structure of wild and domesticated emmer wheat populations, gene flow between them, and the site of emmer domestication. Theor Appl Genet 114:947–959 Luo MC, Xu K, Ma Y, Deal KR, Nicolet CM, Dvorak J (2009) A high-throughput strategy for screening of bacterial artificial chromosome libraries and anchoring of clones on a genetic map constructed with single nucleotide polymorphisms. BMC Genomics. doi:10.1186/1471-2164-10-28 Lutz J, Hsam SLK, Limpert E, Zeller FJ (1994) Powdery mildew resistance in Aegilops tauschii Coss. and synthetic hexaploid wheats. Genet Resour Crop Evol 41:151–158 Lutz J, Hsam SLK, Limpert E, Zeller FJ (1995) Chromosomal location of powdery mildew resistance genes in Triticum aestivum L. (common wheat) 2. Genes Pm2 and Pm19 from Aegilops squarrosa L. Heredity 74:152–156 Ma ZQ, Gill BS, Sorrells ME, Tanksley SD (1993) RFLP markers linked to Hessian fly-resistance genes in wheat (Triticum aestivum L.) from Triticum tauschii (Coss.) Schmal. Theor Appl Genet 85:750–754 Maan SS (1975) Exclusive preferential transmission of an alien chromosome in common wheat. Crop Sci 15:287–292 Mac Key J (2005) Wheat: its concept, evolution and taxonomy. In: Royo C et al. (eds) Durum wheat breeding. Current approaches and future strategies, vol 1, pp 3–61 Makino T (1976) Genetic studies on alien chromosome addition to a durum wheat. I. Some characteristics of seven monosomic addition lines of Aegilops umbellulata chromosomes. Can J Genet Cytol 18:455–462 Makino T (1981) Cytogenetic studies on the alien chromosome addition to durum wheat. Bull Tohoku Natl Agric Exp Stn 65:1–58 Makkouk KM, Comeau A, Ghulam W (1994) Resistance to barley yellow dwarf luteovirus in Aegilops species. Can J Plant Sci 74:631–634 Malik R, Brown-Guedira GL, Smitha CM, Harvey TL, Gill BS (2003) Genetic mapping of wheat curl mite resistance genes Cmc3 and Cmc4 in common wheat. Crop Sci 43:644–650 Marais GF, McCallum BD, Snyman JE, Pretorius ZA, Wellings CR, Marais AS (2005) Lr54 and Yr37 – rust resistance genes derived from Triticum kotschyi. Plant Breed 124:538–541 Marais GF, McCallum B, Marais SA (2006) Leaf rust and stripe rust resistance genes derived from Aegilops sharonensis. Euphytica 149:373–380 Marais GF, McCallum B, Marais AS (2008) Wheat leaf rust resistance gene Lr59 derived from Aegilops peregrina. Plant Breed 127:340–345 Martin TJ, Harvey TL, Hatchett JH (1982) Registration of greenbug and Hessian fly resistant wheat germplasm. Crop Sci 22:1089 Martini G, O’dell M, Flavell RB (1982) Partial inactivation of wheat nucleolus organisers by the nucleolus organiser chromosomes from Aegilops umbellulata. Chromosoma 84:687–700 Martin-Sanchez JA, Gomez-Colmenarejo M, Del Moral J, Sin E, Montes MJ, Gonzalez-Belinchon C, Lopez-Brana I, Delibes A (2003) A new Hessian fly resistance gene (H30) transferred from the wild grass Aegilops triuncialis to hexaploid wheat. Theor Appl Genet 106:1248–1255 70 Masci S, D’Ovidio R, Lafiandra D, Tanzarella A, Porceddu E (1992) Electrophoretic and molecular analysis of alpha-gliadins in Aegilops species (Poaceae) belonging to the D genome cluster and their putative progenitors. Plant Syst Evol 179:115–128 Mason-Gamer R (2005) The beta-amylase genes of grasses and a phylogenetic analysis of the Triticeae (Poaceae). Am J Bot 92:1045–1058 Masoudi-Nejad A, Nasuda S, McIntosh RA, Endo TR (2002) Transfer of rye chromosome segments to wheat by a gametocidal system. Chrom Res 10:349–357 Massa AN, Morris CF, Gill BS (2004) Sequence diversity of puroindoline-a, puroindoline-b and the grain softness protein genes in Aegilops tauschii Coss. Crop Sci 44:1808–1816 Massa AN, Morris CF (2006) Molecular evolution of the puroindoline-a, puroindoline-b, and grain softness protein-1 genes in the tribe Triticeae. J Mol Evol 63:526–536 Matsuoka Y, Nasuda S (2004) Durum wheat as a candidate for the unknown female progenitor of bread wheat: an empirical study with a highly fertile F1 hybrid with Aegilops tauschii Coss. Theor Appl Genet 109:1710–1717 Matsuoka Y, Mori N, Kawahara T (2005) Genealogical use of chloroplast DNA variation for intraspecific studies of Aegilops tauschii Coss. Theor Appl Genet 111:265–271 Matsuoka Y, Takumi S (2007) Natural variation for fertile triploid F1 hybrid formation in allohexaploid wheat speciation. Theor Appl Genet 115:509–518 Matsuoka Y, Takumi S, Kawahara T (2008) Flowering time diversification and dispersal in central Eurasian wild wheat Aegilops tauschii Coss.: genealogical and ecological framework. PlOS One 3(9):e3138. doi:10.1371/journal.pone.0003138 Maxted N, White K, Valkoun J, Konopka J, Hargreaves S (2008) Towards a conservation strategy for Aegilops species. Plant Genet Resour 6:126–141 McFadden ES, Sears ER (1944) The artificial synthesis of Triticum spelta. Rec Genet Soc Am 13:26–27 McFadden ES, Sears ER (1946) The origin of Triticum spelta and its free-threshing hexaploid relatives. J Hered 37 (81–89):107–116 McIntosh RA (1981) A gene for stem rust resistance in nonhomoeologous chromosomes of hexaploid wheat progenitors. In: Carr DJ (ed) Proceedings of the 13th international botanical congress, Sydney, Australia, p 274 McIntosh RA, Miller TE, Chapman V (1982) Cytogenetical studies in wheat XII. Lr28 for resistance to Puccinia recondita and Sr34 for resistance to P. graminis tritici. Z Pflanzenzucht 89:295–306 McIntosh RA (1988) Catalogue of gene symbols for wheat. In: Miller TE, Koebner RMD (eds) Proceedings of the 7th international wheat genetics symposium. Bath Press, Bath, p 1273 McIntosh RA (1991) Alien sources of diverse resistance in bread wheat. In: Sasakuma T, Kinoshita T (eds) Proceedings of the Kihara memorial international symposium on cytoplasmic engineering in wheat. Nuclear and Organellar Genomes of Wheat Species, Yokohama, Japan, pp 320–332 McIntosh RA, Wellings CR, Park RF (1995) Wheat rusts – an atlas of resistance genes. CSIRO, Kluwer Academic, Australia McIntosh RA, Yamazaki Y, Dubcovsky J, Rogers WJ, Morris CF, Sommers DJ, Appels R, Devos KM (2008) Catalogue of B. Kilian et al. gene symbols for wheat: 2008. In: Appels R, Eastwood R, Lagudah E, Langridge P, Mackay M, McIntyre L, Sharp P (eds) Proceedings of the 11th international wheat genetics symposium, Sydney, Australia, Sydney University Press, Australia McKendry AL, Henke GE (1994) Evaluation of wheat wild relatives for resistance to Septoria tritici Blotch. Crop Sci 34:1080–1084 Mello-Sampayo T (1971) Promotion of homoeologous pairing in hybrids of Triticum aestivum x Aegilops longissima. Genet Iber 23:1–9 Mello-Sampayo T, Canas AP (1973) Suppression of meiotic chromosome pairing in common wheat. In: Sears ER, Sears LMS (eds) Proceedings of the 4th international wheat genetics symposium, Columbia, Missouri, USA, pp 703–713 Mettin D, Bl€ uthner WD, Sch€afer HJ, Buchholtz U, Rudolph A (1977) Untersuchungen an Samenproteinen in der Gattung Aegilops. Tagungsber Akad Landwirtschaftswiss DDR 158:95–106 Mihova S (1988) The resistance of Aegilops species to Puccinia striiformis West f. sp. tritici in relation with their ploidy and genome composition. Genet Selekt 21:20–25 Miller TE (1983) Preferential transmission of alien chromosomes in wheat. In: Brandham PE, Bennett MD (eds) Proceedings of 2nd Kew chromosomes conference. George Allen & Unwin, London, UK, pp 173–182 Miller TE, Reader SM (1987) A guide to the homoeology of chromosomes within the Triticeae. Theor Appl Genet 74:214–217 Miller TE, Reader SM, Ainsworth CC, Summers RW (1987) The introduction of a major gene for resistance to powdery mildew of wheat, Erysiphe graminis f. sp. tritici, from Aegilops speltoides into wheat. In: Jorna ML, Shootmaker LAJ (eds) Cereal breeding related to integrated cereal production. Proceedings of EUCARPIA conference, Wageningen, Netherlands, pp 179–183 Miller TE, Reader SM, Mahmood A, Purdie KA, King IP (1995) Chromosome 3N of Aegilops uniaristata – a source of tolerance to high levels of aluminium for wheat. In: Li ZS, Xin Z (eds) Proceedings of the 8th international wheat genetics symposium. China Agricultural Scientech, Beijing, PRC, pp 1037–1042 Miller TE, Iqbal N, Reader SM, Mahmood A, Cant KA, King IP (1997) A cytogenetic approach to the improvement of aluminium tolerance in wheat. New Phytol 137:93–98 Millet E, Avivi Y, Zaccai M, Feldman M (1988) The effect of substitution of chromosome 5S1 of Aegilops longissima for its wheat homoeologues on spike morphology and on several quantitative traits. Genome 30:473–478 Millet E (2006) Rescue collection of Aegilops sharonensis in Israel. Report submitted to IPGRI. http://www.ecpgr.cgiar. org/Networks/Cereals/Aegilops_collection_report.pdf Millet E, Manisterski J, Ben-Yehuda P (2007) Exploitation of wild cereals for wheat improvement in the Institute for Cereal Crops Improvement. In: Maxted N (ed) Crop wild relative conservation and use. CAB International, Wallingford, UK, pp 554–563 Miranda LM, Murphy JP, Marshall D, Leath S (2006) Pm34: a new powdery mildew resistance gene transferred from Aegilops tauschii Coss. to common wheat (Triticum aestivum L.). Theor Appl Genet 113(8):1497 1 Aegilops Miranda LM, Murphy JP, Marshall D, Cowger C, Leath S (2007) Chromosomal location of Pm35, a novel Aegilops tauschii derived powdery mildew resistance gene introgressed into common wheat (Triticum aestivum L.). Theor Appl Genet 114:1451–1456 Miyashita NT, Mori N, Tsunewaki K (1994) Molecular variation in chloroplast DNA regions in ancestral species of wheat. Genetics 137:883–889 Monneveux P, Zaharieva M, Rekika D (2000) The utilisation of Triticum and Aegilops species for the improvement of durum wheat. In: Royo C, Nachit MM, Di Fonzo N, Araus JL (eds) Durum wheat improvement in the Mediterranean region. Options Méditerranéennes, Serie A: Seminaires Méditerranéens (CIHEAM) 40:71–81 Monte JV, De Nova PJG, Soler C (2001) AFLP-based analysis to study genetic variability and relationships in the Spanish species of the genus Aegilops. Hereditas 135:233–238 Montes MJ, Andrés MF, Sin E, López-Braña I, Martı́n-Sánchez JA, Romero MD, Delibes A (2008) Cereal cyst nematode resistance conferred by the Cre7 gene from Aegilops triuncialis and its relationship with Cre genes from Australian wheat cultivars. Genome 51:315–319 Mori N, Liu YG, Tsunewaki K (1995) Wheat phylogeny determined by RFLP analysis of nuclear DNA. 2. Wild tetraploid wheats. Theor Appl Genet 90:129–134 Mori N, Ishii T, Ishido T, Hirosawa S, Watatani H, Kawahara T, Nesbitt M, Belay G, Takumi S, Ogihara Y, Nakamura C (2003) Origin of domesticated emmer and common wheat inferred from chloroplast DNA fingerprinting. In: Proceedigs of the 10th international wheat genetics symposium, Paestum, Italy, pp 25–28 Morris CF, Simeone MC, Gill BS, Mason-Gamer RJ, Lillemo M (2001) Comparison of puroindoline sequences from various diploid members of the Triticeae and modern cultivated hexaploid wheats. Cereals 2000. In: Wootton M, Batey IL, Wrigley CW (eds) Proceedings of the 11th ICC cereal and bread congress and the 50th Australian cereal chemistry conference. Royal Australian Chemical Institute, North Melbourne, Victoria, Australia, pp 678–681 Morris CF (2002) Puroindolines: the molecular genetic basis of wheat grain hardness. Plant Mol Biol 48:633–647 Moullet O, Zhang HB, Lagudah ES (1999) Construction and characterisation of a large DNA insert library from the D genome of wheat. Theor Appl Genet 99:303–313 Mujeeb-Kazi A, Kimber G (1985) The production, cytology and practicality of wide hybrids in the Triticeae. Cereal Res Commun 13:111–124 Muramatsu M (1973) Genetic homology and cytological differentiation of the homoeologous-group-5 chromosomes of wheat and related species. In: Sears ER, Sears LMS (eds) Proceedings of the 4th international wheat genetics symposium. Agriculture Experiment Station, College of Agriculture, University of Missouri, Columbia, USA, pp 719–724 Naik S, Gill KS, Prakasa Rao VS, Gupta VS, Tamhankar SA, Pujar S, Gill BS, Ranjikar PK (1998) Identification of an STS marker linked to the Aegilops speltoides-derived leaf rust resistance gene Lr28 in wheat. Theor Appl Genet 97:535–540 Narasimhamoorthy B, Gill BS, Fritz AK, Nelson JC, BrownGuedira GL (2006) Advanced backcross QTL analysis of a hard winter wheat x synthetic wheat population. Theor Appl Genet 112:787–796 71 Nesbitt M, Samuel D (1996) From stable crop to extinction? The archaeology and history of the hulled wheats. In: Padulosi S, Hammer K, Heller J (eds) Hulled wheats. International Plant Genetics Resource Institute, Rome, Italy and IPK Gatersleben, Germany, pp 41–100 Netzle S, Zeller FJ (1984) Cytogenetic relationship of Aegilops longissima chromosomes with common wheat chromosomes. Plant Syst Evol 145:1–13 Nielsen J (1981) Is there a quick screening method for identifying wheat varieties resistant to loose smut? Cereal Res Commun 9:249–252 Nilmalgoda SD, Cloutier S, Walichnowski AZ (2003) Construction and characterization of a bacterial artificial chromosome (BAC) library of hexaploid wheat (Triticum aestivum L.) and validation of genome coverage using locus-specific primers. Genome 46:870–878 Nishikawa K (1962) Hybrid lethality in crosses between emmer wheats and Aegilops squarrosa, II. Synthesized 6x wheat employed as test varieties. Jpn J Genet 37:227–236 Nishikawa K, Furuta Y, Wada T (1980) Genetic studies on alpha-amylase isozymes in wheat. III. Intraspecific variation in Aegilops squarrosa and birthplace of hexaploid wheat. Jpn J Genet 55:325–336 Nishikawa K (1983) Species relationships of wheat and its putative ancestors as viewed from isozyme variation. In: Sakamoto S (ed) Proceedings of the 6th international wheat genetics symposium. Kyoto University, Kyoto, Japan, pp 59–63 Nkongolo KK, Quick JS, Limin AE, Fowler DB (1991) Sources and inheritance of resistance to Russian wheat aphid in Triticum species, amphiploids and Triticum tauschii. Can J Plant Sci 71:703–708 Noy-Meir I, Agami M, Anikster Y (1991) Changes in the population density of wild emmer wheat (Triticum turgidum var. dicoccoides) in a Mediterranean grassland. Isr J Bot 40:385–396 Ogbonnaya FC, Seah S, Delibes A, Jahier J, Lopez-Brana I, Eastwood RF, Lagudah ES (2001) Molecular-genetic characterization of a new nematode resistance gene in wheat. Theor Appl Genet 102:623–629 Ohsako T, Wang GZ, Miyashita NT (1996) Polymerase chain reaction-single strand conformational polymorphism analysis of intra- and interspecific variations in organellar DNA regions of Aegilops mutica and related species. Genes Genet Syst 71:281–292 Ohta S (2000) Genetic differentiation and post-glacial establishment of the geographical distribution in Aegilops caudata L. Genes Genet Syst 75:189–196 Okamoto M (1957) Asynaptic effect of chromosome V. Wheat Inf Serv 5:6 Olivera PD, Kolmer JA, Anikster Y, Steffenson BJ (2007) Resistance of Sharon goatgrass (Aegilops sharonensis) to fungal diseases of wheat. Plant Dis 91:942–950 Ortelli S, Winzeler H, Winzeler M, Fried PM, Nösberger J (1996) Leaf rust resistance gene Lr9 and winter wheat yield reduction: I. Yield and yield components. Crop Sci 36:1590–1595 Özgen M, Yildiz M, Ulukan H, Koyuncu N (2004) Association of gliadin protein pattern and rust resistance derived from Aegilops umbellulata Zhuk. in winter Triticum durum Desf. Breed Sci 54:287–290 72 Ozkan A, Levy A, Feldman M (2001) Allopolyploidy-induced rapid genome evolution in the wheat (Aegilops–Triticum) group. Plant Cell 13:1735–1747 Ozkan H, Brandolini A, Schaefer-Pregl R, Salamini F (2002) AFLP analysis of a collection of tetraploid wheats indicates the origin of emmer and hard wheat domestication in southeast Turkey. Mol Biol Evol 19:1797–1801 Özkan H, Tuna M, Arumuganathan K (2003) Nonadditive changes in genome size during allopolyploidization in the wheat (Aegilops-Triticum) group. J Hered 94:260–264 Ozkan H, Brandolini A, Pozzi C, Effgen S, Wunder J, Salamini F (2005) A reconsideration of the domestication geography of tetraploid wheats. Theor Appl Genet 110:1052–1060 Ozkan H, Tuna M, Kilian B, Bloach FS, Mori N, Ohta S (in press) Genome size variation in diploid and tetraploid wild wheats. AoB Plants. Panajiotidis S, Athanasiadis N, Symeonidis L, Karataglis S (2000) Pollen morphology in relation to the taxonomy and phylogeny of some native Greek Aegilops species. Grana 39:126–132 Panayotov I (1980) New cytoplasmic male sterility sources in common wheat: their genetical and breeding considerations. Theor Appl Genet 56:153–160 Paux E, Sourdille P, Salse J, Saintenac C, Choulet F et al (2008) A physical map of the 1Gb bread wheat chromosome 3B. Science 322:101–104 Peil A, Korzun V, Schubert V, Schumann E, Weber WE, Roeder MS (1998) The application of wheat microsatellites to identify disomic Triticum aestivum and Aegilops markgrafii addition lines. Theor Appl Genet 96:138–146 Perretant M, Cadalen T, Charmet G, Sourdille P, Nicolas P, Boeuf C, Tixier MH, Branlard G, Bernard S, Bernard M (2000) QTL analysis of bread making quality in wheat using a doubled haploid population. Theor Appl Genet 100:1167–1175 Pestsova E, Korzun V, Goncharov NP, Hammer K, Ganal MW, Röder MS (2000) Microsatellite analysis of Aegilops tauschii germplasm. Theor Appl Genet 101:100–106 Peterson R (1965) Wheat, botany, cultivation, and utilization. Leonard Hill Books and Interscience, London, UK Petersen G, Seberg O, Yde M, Berthelsen K (2006) Phylogenetic relationships of Triticum and Aegilops and evidence for the origin of the A, B, and D genomes of common wheat (Triticum aestivum). Mol Phylogenet Evol 39:70–82 Pietro ME, Tuleen NA, Hart GE (1988) Development of wheat –Triticum searsii disomic chromosome addition lines. In: Koebner R, Miller TE (eds) Proceedings of the 7th international wheat general symposium. Institute of Plant Science Research, Cambridge, UK, pp 409–413 Pignone D, Galasso I, Hammer K, Perrino P (1992) Cytotaxonomy of Aegilops fragilis, a race from southern Italy. Hereditas 116:137–140 Provan J, Wolters P, Caldwell KH, Powell W (2004) Highresolution organellar genome analysis of Triticum and Aegilops sheds new light on cytoplasm evolution in wheat. Theor Appl Genet 108:1182–1190 Pluzhnikov A, Donnelly P (1996) Optimal sequencing strategies for surveying molecular genetic diversity. Genetics 144: 1247–1262 Qi L, Friebe B, Zhang P, Gill BS (2007) Homoeologous recombination, chromosome engineering and crop improvement. Chrom Res 15:319 B. Kilian et al. Qiu YC, Sun XL, Zhou RH, Kong XY, Zhang SS, Jia JZ (2006) Identification of microsatellite markers linked to powdery mildew resistance gene Pm2 in wheat. Cereal Res Commun 34:1267–1273 Rahman S, Jolly JC, Skerritt JH, Wallosheck A (1994) Cloning of a wheat 15 kDA grain softness protein (GSP), GSP is a mixture of puroindoline-like polypeptides. Eur J Biochem 223:917–925 Raupp WJ, Gill BS, Browder LE (1983) Leaf rust resistance in Aegilops squarrosa L., its transfer and expression in common wheat (Triticum aestivum L.). Phytopathology 73:818–822 Raupp WJ, Amri A, Hachett JH, Gill BS, Wilson DL, Cox TS (1993) Chromosomal location of Hessian fly resistance genes H22, H23 and H24 from Triticum tauschii in the D genome of wheat. J Hered 84:142–145 Raupp WJ, Sukhwinder-Singh B-G, GL GBS (2001) Cytogenetic and molecular mapping of the leaf rust resistance gene Lr39 in wheat. Theor Appl Genet 102:347–352 Rayburn AL, Gill BS (1985) Use of biotin-labelled probes to map specific DNA sequence on wheat chromosomes. J Hered 76:78–81 Rekika D, Zaharieva M, Stankova P, Xu X, Souyris I, Monneveux P (1998) Abiotic stress tolerance in Aegilops species. In: Nachit MM, Baum M, Porceddu E, Monneveux P, Picard E (eds) Durum research network, Proceedings of SEWANA, South Europe, West Asia and North Africa, ICARDA, Aleppo, Syria, pp 113–128 Raskina O, Belyayev A, Nevo E (2002) Repetitive DNAs of wild emmer wheat (Triticum dicoccoides) and their relation to S-genome species: molecular cytogenetic analysis. Genome 45:391–401 Raskina O, Belyayev A, Nevo E (2004) Quantum speciation in Aegilops: molecular cytogenetic evidence from rDNA cluster variability in natural populations. Proc Natl Acad Sci USA 101:14818–14823 Riley R, Chapman V (1958) Genetic control of the cytologically diploid behaviour of hexaploid wheat. Nature 182:713–715 Riley R, Unrau J, Chapman V (1958) Evidence on the origin of the B genome of wheat. J Hered 49:91–98 Riley R (1966) The genetic regulation of meiotic behaviour in wheat and its relatives. In: Mac Key J, (ed) Proceedings of 2nd international wheat genet symposium, Lund, Sweden. Hereditas 2:395–408 Riley R, Chapman V, Macer RCF (1966) The homoeology of an Aegilops chromosome causing stripe rust resistance. Can J Genet Cytol 8:616–630 Riley R, Chapman V, Johnson R (1968) The incorporation of alien disease resistance in wheat by genetic interference with the regulation of meiotic chromosome synapsis. Genet Res (Camb) 12:199–219 Riley R, Chapman V, Miller TE (1971) Annual Report of Plant Breeding Institute, Cambridge (cited in Shepherd and Islam 1988) Riley R, Chapman V, Miller TE (1973) The determination of meiotic chromosome pairing. In: Proceedings of the 4th international wheat genetics symposium, Columbia, Missouri, USA, pp 731–738 Rodriguez-Quijano M, Nieto-Taladriz MT, Carrillo JM (1996) Linkage mapping of prolamin and isozyme genes on the 1Sl chromosome of Aegilops longissima. Theor Appl Genet 93:295–299 1 Aegilops Rodriguez-Quijano M, Carrillo JM (1996) Relationship between allelic variation of Glu-1 and Gli-1/Glu-3 prolamin loci and gluten strength in hexaploid wheat. Euphytica 91:141–148 Romero MD, Montes MJ, Sin E, Lopez-Brana I, Duce A, Martin-Sanchez á JA, Andrés MF, Delibes A (1998) A cereal cyst nematode (Heterodera avenae Woll.) resistance gene transferred from Aegilops triuncialis to hexaploid wheat. Theor Appl Genet 96:1135–1140 Rowland GC, Kerber ER (1974) Telocentric mapping in hexaploid wheat of genes for leaf rust resistance and other characters derived from Aegilops squarrosa. Can J Genet Cytol 16:137–144 Saeidi H, Rahiminejad MR, Heslop-Harrison JS (2008) Retroelement insertional polymorphisms, diversity and phylogeography within diploid, D-genome Aegilops tauschii (Triticeae, Poaceae) sub-taxa in Iran. Ann Bot 101:855–861 Sakamoto S (1982) The Middle East as a cradle for crops and weeds. In: Holzner W, Numata N (eds) Biology and ecology of weeds. Dr. Junk, The Hague-Boston-London, pp 97–109 Sakamura T (1918) Kurze Mitteilung € uber die Chromosomenzahlen und die Verwandtschaftsverh€altnisse der Triticum Arten. Bot Mag (Tokyo) 32:151–154 Salamini F, Özkan H, Brandolini A, Sch€afer-Pregl R, Martin W (2002) Genetics and geography of wild cereal domestication in the near east. Nat Rev Genet 3:429–441 Salina EA, Lim KY, Badaeva ED, Shcherban AB, Andrey B, Adonina IG, Amosova AV, Samatadze TE, Vatolina TY, Zoshchuk SA, Leitch AR (2006) Phylogenetic reconstruction of Aegilops section Sitopsis and the evolution of tandem repeats in the diploids and derived wheat polyploids. Genome 49:1023–1035 Sallares R, Brown TA (1999) PCR-based analysis of the intergenic spacers of the Nor loci on the A genomes of Triticum diploids and polyploids. Genome 42:116–128 Sallares R, Brown TA (2004) Phylogenetic analysis of complete 5´ external transcribed spacers of the 18S ribosomal RNA genes of diploid Aegilops and related species (Triticeae, Poaceae). Genet Resour Crop Evol 51:701–712 Salse J, Chagué V, Bolot S, Magdelenat G, Huneau C, Pont C, Belcram H, Couloux A, Gardais S, Evrard A, Segurens B, Charles M, Ravel C, Samain S, Charmet G, Boudet N, Chalhoub B (2008) New insights into the origin of the B genome of hexaploid wheat: evolutionary relationships at the SPA genomic region with the S genome of the diploid relative Aegilops speltoides. BMC Genom 9:555. doi:10.1186/1471-2164-9-555 Sambasivam PK, Bansal UK, Hayden MJ et al. (2008) Identification of markers linked with stem rust resistance genes Sr33 and Sr45. In: Appels R, Eastwood R, Lagudah ES, Langridge P, MacKay M, McIntyre L, Sharp P (eds) Proceedings of the 11th international wheat genetics symposium, Brisbane, Australia. http://ses.library.usyd.edu.au/handle/2123/3168 SanMiguel P, Gaut BS, Tikhonov A, Nakajima Y, Bennetzen JL (1998) The paleontology of intergene retrotransposons of maize: dating the strata. Nat Genet 20:43–45 Sarkar P, Stebbins GI (1956) Morphological evidence concerning the origin of the B genome in wheat. Am J Bot 43:297–304 Sasanuma T, Miyashita NT, Tsunewaki K (1996) Wheat phylogeny determined by RFLP analysis of nuclear DNA. 3. 73 Intra- and interspecific variations of five Aegilops Sitopsis species. Theor Appl Genet 92:928–934 Sasanuma T, Chabane K, Endo TR, Valkoun J (2002) Genetic diversity of wheat wild relatives in the near east detected by AFLP. Euphytica 127:81–93 Sasanuma T, Chabane K, Endo TR, Valkoun J (2004) Characterization of genetic variation in and phylogenetic relationships among diploid Aegilops species by AFLP: incongruity of chloroplast and nuclear data. Theor Appl Genet 108:612–618 Sax K, Sax MJ (1924) Chromosome behaviour in a genus cross. Genetics 9:454–464 Schneider A, Linc G, Molnar I, Molnar-Lang M (2005) Molecular cytogenetic characterization of Aegilops biuncialis and its use for the identification of five derived wheat/Aegilops biuncialis disomic addition lines. Genome 48:1070–1082 Scholz H, van Slageren MW (1994) Proposal to conserve Aegilops caudata (Gramineae) with a conserved type. Taxon 43:293–296 Schubert V, Bl€ uthner WD (1995) Triticum aestivum-Aegilops markgrafii addition lines: production and morphology. In: Li ZS, Xin ZY (eds) Proceedings of the 8th wheat international genetics symposium. China Agricultural Scientech, Beijing, China, pp 421–425 Seah S, Bariana H, Jahier J, Sivasithamparam K, Lagudah ES (2001) The introgressed segment carrying rust resistance genes Yr17, Lr37 and Sr38 in wheat can be assayed by a cloned disease resistance gene-like sequence. Theor Appl Genet 102:600–605 Sears ER (1954) The aneuploids of common wheat. Res Bull MO Agric Exp Stn 572:1–57 Sears ER (1956) The transfer of leaf rust resistance from Aegilops umbellulata to wheat. Brookhaven Symp Biol 9:1–22 Sears ER (1977) An induced mutant with homoeologous pairing in common wheat. Can J Genet Cytol 19:585–593 Sears ER (1981) Transfer of alien genetic material to wheat. In: Evans WJ, Peacock LT (eds) Wheat science – today and tomorrow. Cambridge University Press, Cambridge, UK, pp 75–89 Sears ER (1983) The transfer to wheat of interstitial segments of alien chromosomes. In: Sakamoto S (ed) Proceedings of the 6th international wheat genetics symposium. Plant Germplasm Institute, Faculty of Agriculture, Kyoto University, Kyoto, Japan, pp 5–12 Sears ER, Gustafson JP (1993) Use of radiation to transfer alien chromosome segments to wheat. Crop Sci 33:897–901 Seberg O, Frederiksen S (2001) A phylogenetic analysis of the monogenomic Triticeae (Poaceae) based on morphology. Bot J Linn Soc 136:75–97 Seyfarth R, Feuillet C, Schachermayr G, Winzeler M, Keller B (1999) Development of a molecular marker for the adult plant leaf rust resistance gene Lr35 in wheat. Theor Appl Genet 99:554–560 Sharma HC, Gill BS (1983) Current status of wide hybridization in wheat. Euphytica 32:17–31 Shepherd KW (1973) Homology of wheat and alien chromosomes controlling endosperm protein phenotypes. In: Sears ER, Sears LMH (eds) Proceedings of the 4th international wheat genetics symposium. University of Missouri, Columbia, Missouri, UK, pp 745–760 Shepherd KW, Islam AKMR (1988) Fourth compendium of wheat-alien chromosome lines. In: Miller TE, Koebner RMD 74 (eds) Proceedings of the 7th international wheat genetics symposium, Cambridge, UK, pp 1373–1395 Shindo C, Sasakuma T (2001) Early heading mutants of T. monococcum and Ae. squarrosa, A- and D-genome ancestral species of hexaploid wheat. Breed Sci 51:95–98 Shizuya H, Birren B, Kim U-J, Mancino V, Slepak T, Tachiiri Y, Simon M (1992) Cloning and stable maintenance of 300-kilobase-pair fragments of human DNA of Escherichia coli using an F-factor-based vector. Proc Natl Acad Sci USA 89:8794–8797 Singh RP, Nelson JC, Sorrells ME (2000) Mapping Yr28 and other genes for resistance to stripe rust in wheat. Crop Sci 40:1148–1155 Singh RP, Hodson DP, Jin Y, Huerta-Espino J, Kinyua MG, Wanyera R, Njau P, Ward RW (2006) Current status, likely migration and strategies to mitigate the threat to wheat production from race Ug99 (TTKS) of stem rust pathogen. CAB Rev Perspect Agric Vet Sci Nutr Nat Resour 1:1–13 Singh S, Franks CD, Huang L, Brown-Guedira GL, Marshall DS, Gill BS, Fritz A (2004) Lr41, Lr39, and a leaf rust resistance gene from Aegilops cylindrica may be allelic and are located on wheat chromosome 2DS. Theor Appl Genet 108:586–591 Smith CM, Starkey S (2003) Resistance to greenbug (Homoptera: Aphididae) biotype I in Aegilops tauschii synthetic wheats. J Econ Entomol 96:1571–1576 Snyder JR, Mallory-Smith CA, Balter S, Hansen JL, Zemetra RS (2000) Seed production on Triticum aestivum by Aegilops cylindrica hybrids in the field. Weed Sci 48:588–593 Song W, Xie H, Liu Q, Chaojie X, Ni Z, Yang T, Sun Q, Liu Z (2007) Molecular identification of Pm12-carrying introgression lines in wheat using genomic and EST-SSR markers. Euphytica 158:95–102 Sourdille P, Perretant MR, Charmet G, Leory P, Gautire MF, Joudrier P, Nelson JC, Sorrells ME, Bernard M (1996) Linkage between RFLP markers and genes affecting kernel hardness in wheat. Theor Appl Genet 93:580–586 Spetsov P, Mingeot D, Jacquemin JM, Samardjieva K, Marinova E (1997) Transfer of powdery mildew resistance from Aegilops variabilis into bread wheat. Euphytica 93:49–54 Spielmeyer W, Huang L, Bariana H, Laroche A, Gill BS, Lagudah ES (2000a) NBS-LRR sequence family is associated with leaf and stripe rust resistance on the end of homoeologous chromosome group 1S of wheat. Theor Appl Genet 101:1139–1144 Spielmeyer W, Moullet O, Laroche A, Lagudah ES (2000b) High recombinogenic regions at seed storage protein loci on chromosome 1DS of Aegilops tauschii, the D-genome donor of wheat. Genetics 155:361–367 Stoilova T, Spetsov P (2006) Chromosome 6U from Aegilops geniculata Roth carrying powdery mildew resistance in bread wheat. Breed Sci 56:351–357 Stolton S, Maxted N, Ford-Lloyd BV, Kell SP, Dudley N (2006) Food stores: using protected areas to secure crop genetic diversity. WWF Arguments for Protection Series, Gland, Switzerland Sz€ucs P, Karsai I, von Zitzewitz J, Meszaros K, Cooper LL, Gu YQ, Chen TH, Hayes PM, Skinner JS (2006) Positional relation- B. Kilian et al. ship between photoperiod response QTL and photoreceptor and vernalization genes in barley. Theor Appl Genet 112:1277–1285 ucs P, Skinner JS, Karsai I, Cuesta-Marcos A, Haggard KG, Sz€ Corey AE, Chen THH, Hayes PM (2007) Validation of the VRN-H2/VRN-H1 epistatic model in barley reveals that intron length variation in VRN-H1 may account for a continuum of vernalization sensitivity. Mol Genet Genomics 277:249–261 Tadesse W, Hsam SLK, Wenzel G, Zeller FJ (2006) Identification and monosomic analysis of tan spot resistance genes in synthetic wheat lines (Triticum turgidum L. x Aegilops tauschii Coss.). Crop Sci 46:1212–1217 Takumi S, Nasuda S, Liu YG, Tsunewaki K (1993) Wheat phylogeny determined by RFLP analysis of nuclear DNA. 1. Einkorn wheat. Jpn J Genet 68:73–79 Talbert LE, Smith LY, Blake NK (1998) More than one origin of hexaploid wheat is indicated by sequence comparison of low-copy DNA. Genome 41:402–407 Tanno K, Willcox G (2006) How fast was wild wheat domesticated? Science 311:1886 Thuillet A-C, Bataillon T, Poirier S, Santoni S, David JL (2005) Estimation of long-term effective population sizes through the history of durum wheat using microsatellite data. Genetics169:1589–1599 Tranquilli G, Lijavetzky D, Muzzi G, Dubcovsky J (1999) Genetic and physical characterization of grain texturerelated loci in diploid wheat. Mol Gen Genet 262:846–850 Trethowan RM, Borja J, Mujeeb-Kazi A (2003) The impact of synthetic wheat on breeding for stress tolerance at CIMMYT. Annu Wheat Newsl 49:67–69 Trevaskis B, Hemming MN, Peacock WJ, Dennis ES (2006) HvVRN2 responds to daylength, whereas HvVRN1 is regulated by vernalization and developmental status. Plant Physiol 140:1397–1405 Tsujimoto H, Tsunewaki K (1984) Gametocidal genes in wheat and its relatives. I. Genetic analyses in common wheat of a gametocidal gene derived from Aegilops speltoides. Can J Genet Cytol 26:78–84 Tsujimoto H, Tsunewaki K (1988) Gametocidal genes in wheat and its relatives. III. Chromosome location and effects of two Aegilops speltoides-derived gametocidal genes in common wheat. Genome 30:239–244. Tsujimoto H (2005) Gametocidal genes in wheat as inducer of chromosome breakage. In: Tsunewaki K (ed) Frontiers of wheat bioscience, Wheat Information Service 100th Memorial Issue. Kihara Memorial Yokohama Foundation, Yokohama, Japan, pp 33–48 Tsunewaki K (1982) Monosomic analysis on the fertility restoration by Triticum aestivum cv. Chinese Spring against Aegilops ovata cytoplasm. Jpn J Genet 57:513–525 Tsunewaki K (1993) Genome-plasmon interactions in wheat. Jpn J Genet 68:1–34 Tsunewaki K, Endo TR, Mukai Y (1974) Further discovery of alien cytoplasms inducing haploids and twins in common wheat. Theor Appl Genet 45:104–109 Tsunewaki K, Ogihara Y (1983) The molecular basis of genetic diversity among cytoplasms of Triticum and Aegilops species. II. On the origin of polyploidy wheat cytoplasm as suggested by chloroplast DNA restriction fragment patterns. Genetics 104:155–171 1 Aegilops Tsunewaki K, Wang GZ, Matsuoka Y (1996) Plasmon analysis of Triticum (wheat) and Aegilops. 1. Production of alloplasmic common wheats and their fertilities. Genes Genet Syst 71:293–311 Tsunewaki K, Wang GZ, Matsuoka Y (2002) Plasmon analysis of Triticum (wheat) and Aegilops. 2. Characterization and classification of 47 plasmons based on their effects on common wheat phenotype. Genes Genet Syst 77:409–427 Tutin TG, Humphries CJ (1980) Aegilops L. In: Tutin TG, Heywood VH, Burges NA, Moore DM, Valentine DH, Walters SM, Webb DA (eds) Flora Europaea, vol 5. Cambridge University Press, Cambridge, pp 200–202 Turnbull K, Turner M, Mukai Y, Yamamoto M, Morell MK, Appels R, Rahman S (2003) The organization of genes tightly linked to the Ha locus in Ae. tauschii, the D genome donor of wheat. Genome 46:330–336 Turner A, Beales J, Faure S, Dunford RP, Laurie DA (2005) The pseudo-response regulator Ppd-H1 provides adaptation to photoperiod in barley. Science 310:1031–1034 Vakhitov VA, Chemeris AV, Sabirzhanov BE, Akhunov ED, Kulikov AM, Nikonorov YM, Gimalov FR, Bikbulatova SM, Baymiev AK (2003) The phylogeny of Triticum L. and Aegilops L. inferred from comparative analysis of nucleotide sequences in rDNA promoter regions. Russ J Genet 39:1–11 Valkoun J, Kucerova D, Bartos P, Hammer K (1985) Study of disease resistance in the genus Aegilops for its use in wheat breeding. In: Proceedings of the EUCARPIA genetics research section, international symposium, Prague, Czech Republic, pp 241–251 Valkoun J, Damania AB (1992) Gliadin diversity in populations of Triticum urartu and T. dicoccoides in Syria. Reproductive biology and plant breeding. Book of Poster Abstracts. In: XIII EUCARPIA Congress, Angers, France Vanichanon A, Blake NK, Sherman JD, Talbert LE (2003) Multiple origins of allopolyploid Aegilops triuncialis. Theor Appl Genet 106:804–810 Van Slageren MW (1994) Wild wheats: a monograph of Aegilops L. and Amblyopyrum (Jaub. & Spach) Eig (Poaceae). Agricultural University Papers, Wageningen, Netherlands Vavilov NI (1951) Phytogeographic basis of plant breeding. In: The origin, variation, immunity and breeding of cultivated plants. (Chester KS, transl.). Chron Bot 13:14–54 Von Zitzewitz J, Sz€ucs P, Dubcovsky J, Yan L, Francia E, Pecchioni N, Casas A, Chen THH, Hayes PM, Skinner JS (2005) Molecular and structural characterization of barley vernalization genes. Plant Mol Biol 59:449–467 Waines JG, Rafi MM, Ehdaie B (1993) Yield components and transpiration efficiency in wild wheats. In: Damania AB (ed) Biodiversity and wheat improvement. Wiley, Chichester, UK, pp 173–186 Waines JG (1994) High temperature in wild wheats and spring wheats. Aust J Plant Physiol 21:705–715 Waines JG, Hegde SG (2003) Intraspecific gene flow in bread wheat (Triticum aestivum L.) as affected by reproductive biology and pollination ecology of wheat flowers. Crop Sci 43:451–463 Wang GZ, Miyashita N, Tsunewaki K (1997) Plasmon analysis of Triticum (wheat) and Aegilops: PCR-single strand conformation polymorphism (PCR-SSCP) analyses of organellar DNAs. Proc Natl Acad Sci USA 94:14570–14577 75 Wang JB, Wang C, Shi SH, Zhong Y (2000) Evolution of parental ITS regions of nuclear rDNA in allopolyploid Aegilops (Poaceae) species. Hereditas 133:1–7 Wang T, Xu SS, Harris MO, Hu J, Liu L, Xiwen C (2006) Genetic characterization and molecular mapping of Hessian fly resistance genes derived from Aegilops tauschii in synthetic wheat. Theor Appl Genet 113:611–618 Weiss E, Kislev ME, Hartmann A (2006) Autonomous cultivation before domestication. Science 312:1608–1610 Wells DG, Kota RS, Sandhu HS, Gardner WAS, Finney KF (1982) Registration of one disomic substitution line and five translocation lines of winter wheat germplasm resistant to wheat streak mosaic virus. Crop Sci 22:1277–1278 Weng Y, Lazar MD (2002) Amplified fragment length polymorphism-and simple sequence repeat-based molecular tagging and mapping of greenbug resistance gene Gb3 in wheat. Plant Breed 121:218–223 Weng Y, Li W, Devkota RN, Rudd JC (2005) Microsatellite markers associated with two Aegilops tauschii-derived greenbug resistance loci in wheat. Theor Appl Genet 110:462–469 Whitcombe, JR, 1983. A guide to the species of Aegilops L.: their taxonomy, morphology, and distribution. International Board for Plant Genetic Resources (IPGRI), Rome, Italy, 74p Wicker T, Schlagenhauf E, Graner A, Close TJ, Keller B, Stein N (2006) 454 sequencing put to the test using the complex genome of barley. BMC Genom 7:275 William MDHM, Pena RJ, Mujeeb-Kazi A (1993) Seed protein and isozyme variations in Triticum tauschii (Aegilops squarrosa). Theor Appl Genet 87:257–263 Worland A (1996) The influence of flowering time genes on environmental adaptability in European wheats. Euphytica 89:49–57 Yamane K, Kawahara T (2005) Intra- and interspecific phylogenetic relationships among diploid Triticum-Aegilops species (Poaceae) based on base-pair substitutions, indels, and microsatellites in chloroplast noncoding sequences. Am J Bot 92:1887–1898 Yan L, Loukoianov A, Tranquilli G, Helguera M, Fahima T, Dubcovsky J (2003) Positional cloning of the wheat vernalization gene VRN1. Proc Natl Acad Sci USA 100: 6263–6268 Yan L, Helguera M, Kato K, Fukuyama S, Sherman J, Dubcovsky J (2004a) Allelic variation at the VRN-1 promoter region in polyploid wheat. Theor Appl Genet 109:1677–1686 Yan L, Loukoianov A, Blech A, Tranquilli G, Ramakrishna W, SanMiguel P, Bennetzen JL, Echenique V, Dubcovsky J (2004b) The wheat VRN2 gene is a flowering repressor down-regulated by vernalization. Science 303:1640–1644 Yan L, Fu D, Li C, Blechl A, Tranquilli G, Bonafed M, Sanchez A, Valarik M, Yasuda S, Dubcovsky J (2006) The wheat and barley vernalization gene VRN3 is an ortholog of FT. Proc Natl Acad Sci USA 103:19581–19586 Yang Y-C, Tuleen NA, Hart GE (1996) Isolation and identification of Triticum aestivum L. em. Thell. cv. Chinese Spring – T. peregrinum Hackel disomic chromosome addition lines. Theor Appl Genet 92:591–598 Yinhuai Z, Zhengqiang M, Dajun L (1991) Transfer of restoring gene in Aegilops umbellulata to wheat. J Genet Genomics 18:529–536 76 Yu MQ, Jahier J, Person-Dedryver F (1990) Chromosomal location of a gene (Rkn-mnl) for resistance to the root-knot nematode transferred into wheat from Aegilops variabilis. Plant Breed 114:358–360 Yu Y, Tomkins JP, Waugh R, Frisch DA, Kudrna D, Kleinhofs A, Brueggeman RS, Muehlbauer GJ, Wise RP, Wing RA (2000) A bacterial artificial chromosome library for barley (Hordeum vulgare L.) and the identification of clones containing putative resistance genes. Theor Appl Genet 101: 1093–1099 Zaharieva M, Monneveux P (2006) Spontaneous hybridization between bread wheat (Triticum aestivum L.) and its wild relatives in Europe. Crop Sci 46:512–527 Zeller FJ, Kong L, Hartl L, Mohler V, Hsam SLK (2002) Chromosomal location of genes for resistance to powdery mildew in common wheat (Triticum aestivum L. em. Thell.). 7. Gene Pm29 in line Pova. Euphytica 123:187–194 Zhang H, Jia J, Gale MD, Devos KM (1998) Relationships between the chromosomes of Aegilops umbellulata and wheat. Theor Appl Genet 96:69–75 Zhang H, Reader SM, Liu X, Jia JZ, Gale MD, Devos KM (2001) Comparative genetic analysis of the Aegilops longissima and Ae. sharonensis genomes with common wheat. Theor Appl Genet 103:518–525 Zhang W, Qu LJ, Gu H, Gao W, Liu M, Chen J, Chen Z (2002) Studies on the origin and evolution of tetraploid wheats B. Kilian et al. based on the internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA. Theor Appl Genet 104: 1099–1106 Zhang LY, Ravel C, Bernard M, Balfourier F, Leroy P, Feuillet C, Sourdille P (2006) Transferable bread wheat EST-SSR can be useful for phylogenetic studies among the Triticeae species. Theor Appl Genet 113:407–418 Zhu LC, Smith CM, Fritz A, Boyko EV, Flinn MB (2004) Genetic analysis and molecular mapping of a wheat gene conferring tolerance to the greenbug (Schizaphis graminum Rondani). Theor Appl Genet 109:289–293 Zhu LC, Smith CM, Fritz A, Boyko E (2005) Inheritance and molecular mapping of new greenbug resistance genes in wheat germplasm derived from Aegilops tauschii. Theor Appl Genet 111:831–837 Zhu Z, Zhou R, Kong X, Dong Y, Jia J (2006) Microsatellite marker identification of a Triticum aestivum-Aegilops umbellulata substitution line with powdery mildew resistance. Euphytica 150:149–153 Zhukovsky PM (1928) Kritiko-systematicheskii obzor vidov roda Aegilops L. (Specierum generis Aegilops L. revisio critica). Trudy Prikl Bot Genet Selekc [Bull Appl Bot Genet and Plant Breed] 18:417–609 Zohary D, Feldman M (1962) Hybridisation between amphiploids and the evolution of polyploids in the wheat (Aegilops-Triticum) group. Evolution 16:44–61

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