No full-text available
To read the full-text of this research,
you can request a copy directly from the author.
Generic delimitation of Bionectria (Bionectriaceae, Hypocreales) based on holomorph characters and rDNA sequences
Abstract
The holomorphic genus Bionectria, with anamorphs classified in Clonostachys, is characterized and compared to related taxa of the Hypocreales. Bionectria species form penicillate, solitary or sporodochial conidiophores and imbricately arranged conidia held in chains or columns that may collapse into slimy masses. The superficially free ascomata often occur on other fungi, mainly ascomycetes, on bark of recently dead trees, or on decaying leaves. Anamorphs of Bionectria species, such as Clonostachys rosea (= Gliocladlium roseum), are often encountered in soil and are known as destructive mycoparasites. Based mainly on characters of the teleomorph, such as occurrence of a supporting stroma, the interface between the stroma and the perithecial wall, anatomy of the perithecial wall, ascospore morphology, habit on and type of the natural substratum, six infrageneric subgroups are distinguished. Characters of the anamorph, such as the tendency to form dimorphic conidiophores and/or sporodochia, occurrence of intercalary phialides or setae, conidial shape, and pigmentation of conidial masses, partly support the subgroups delimited using teleomorph characters, but all subgroups can be linked with each other by intermediate patterns of anamorphs. Based on the general occurrence of penicillate conidiophores and suspected similarities in their life-styles, classification of all species in one genus is suggested. To address differences found in the anamorphs, the terms dendrodochium-, sesquicillium-, myrothecium-, and gliocladium-like are used. Analyses of rDNA sequences suggest monophyly of all taxa considered, while certain phenotypic characters appear in paraphyletic positions.
... Most cultures examined previously by Schroers et al. (1999b) and Schroers (2000Schroers ( , 2001 were incorporated and newly compared with so far unstudied isolates. Based on phylogenetic analyses of five loci, ITS, LSU, RPB2, TEF1, TUB2, and morphological characters, a rich set of taxa were identified as new species of Clonostachys, Mycocitrus, Nectriopsis, and Sesquicillium ( Fig. 1) and our data support that they all belong to the Bionectriaceae. ...
Clonostachys ( Bionectriaceae , Hypocreales ) species are common soil-borne fungi, endophytes, epiphytes, and saprotrophs. Sexual morphs of Clonostachys spp. were placed in the genus Bionectria , which was further segregated into the six subgenera Astromata , Bionectria , Epiphloea , Myronectria , Uniparietina , and Zebrinella . However, with the end of dual nomenclature, Clonostachys became the single depository for sexual and asexual morph-typified species. Species of Clonostachys are typically characterised by penicillate, sporodochial, and, in many cases, dimorphic conidiophores (primary and secondary conidiophores). Primary conidiophores are mononematous, either verticillium-like or narrowly penicillate. The secondary conidiophores generally form imbricate conidial chains that can collapse to slimy masses, particularly on sporodochia. In the present study, we investigated the species diversity within a collection of 420 strains of Clonostachys from the culture collection of, and personal collections at, the Westerdijk Fungal Biodiversity Institute in Utrecht, the Netherlands. Strains were analysed based on their morphological characters and molecular phylogeny. The latter used DNA sequence data of the nuclear ribosomal internal transcribed spacer regions and intervening 5.8S nrDNA (ITS) and partial 28S large subunit (LSU) nrDNA and partial protein encoding genes including the RNA polymerase II second largest subunit ( RPB2 ), translation elongation factor 1-alpha ( TEF1 ) and β-tubulin ( TUB2 ). Based on these results, the subgenera Astromata , Bionectria , Myronectria and Zebrinella are supported within Clonostachys . Furthermore, the genus Sesquicillium is resurrected to accommodate the former subgenera Epiphloea and Uniparietina . The close relationship of Clonostachys and Sesquicillium is strongly supported as both are inferred phylogenetically as sister-genera. New taxa include 24 new species and 10 new combinations. Recognition of Sesquicillium distinguishes species typically forming a reduced perithecial stroma superficially on plant tissue from species in Clonostachys often forming well-developed, through bark erumpent stromata. The patterns of observed perithecial wall anatomies, perithecial wall and stroma interfaces, and asexual morph diversifications described in a previously compiled monograph are used for interpreting ancestral state reconstructions. It is inferred that the common ancestor of Clonostachys and Sesquicillium may have formed perithecia superficially on leaves, possessed a perithecial wall consisting of a single region, and formed intercalary phialides in penicilli of conidiophores. Character interpretation may also allow hypothesising that diversification of morphs occurred then in the two genera independently and that the frequently stroma-linked Clonostachys morphs evolved together with the occupation of woody host niches and mycoparasitism.
... Schroers et al. (1999a,b) described Bionectria and its anamorph in detail. Schroers (2000Schroers ( , 2001 classifi ed the 35 Bionectria species having the Clonostachys anamorph and 9 other Clonostachys taxa based on detailed morphological and molecular data. In addition, Schroers divided the genus Bionectria into six newly distinguished subgenera, namely Bionectria, Zebrinella, Astromata, Myronectria, Epiphloea, and Uniparietina, based on morphology of stroma, structure of perithecial wall, habit of the perithecia on the natural substratum, ornamentation and septation of ascospores, and phylogenetic data. ...
Based on the result of morphological and the phylogenetic analyses, three Bionectria (Bionectriaceae: Hypocreales) species are added to the mycobiota of Japan. Among them, one found in Okinawa and Kagoshima Prefectures is described as a new species, Bionectria pseudostriatopsis (anamorph: Clonostachys pseudostriatopsis). The other two, B. grammicospora and B. sporodochialis, are new records from Japan. Additional distribution records are given for Bionectria species hitherto known in Japan.
... For some fungi including Mycosphaerella (Crous et al 2001) and Calonectria (Rossman et al 1999, Rossman 2000, Schroers 2000 anamorphic genera could be delineated so that they correlated with phylogenetic groups. In Tubeufia establishing phylogenetically based anamorphic genera will be difficult. ...
Three genera of asexual, helical-spored fungi, Helicoma, Helicomyces and Helicosporium traditionally have been differentiated by the morphology of their conidia and conidiophores. In this paper we assessed their phylogenetic relationships from ribosomal sequences from ITS, 5.8S and partial LSU regions using maximum parsimony, maximum likelihood and Bayesian analysis. Forty-five isolates from the three genera were closely related and were within the teleomorphic genus Tubeufia sensu Barr (Tubeufiaceae, Ascomycota). Most of the species could be placed in one of the seven clades that each received 78% or greater bootstrap support. However none of the anamorphic genera were monophyletic and all but one of the clades contained species from more than one genus. The 15 isolates of Helicoma were scattered through the phylogeny and appeared in five of the clades. None of the four sections within the genus were monophyletic, although species from Helicoma sect. helicoma were concentrated in Clade A. The Helicosporium species also appeared in five clades. The four Helicomyces species were distributed among three clades. Most of the clades supported by sequence data lacked unifying morphological characters. Traditional characters such as the thickness of the conidial filament and whether conidiophores were conspicuous or reduced proved to be poor predictors of phylogenetic relationships. However some combinations of characters including conidium colour and the presence of lateral, tooth-like conidiogenous cells did appear to be predictive of genetic relationships.
... Recent molecular phylogenetic studies have confirmed polyphyly/ paraphyly of many of well-recognized anamorphic genera and species, whose classification is subject to further refinement. Prominent examples include: Acremonium (Glenn et al., 1996); Chalara (Paulin and Harrington, 2000;Paulin et al., 2002;Fernández et al., 2006), Cryptococcus (Fell et al., 2000;Scorzetti et al., 2002), Dendrotrichum (Schroers, 2000), Fusarium (Rossman et al., 1999;Rossman, 2000), Geosmithia (Kolarik et al., 2004(Kolarik et al., , 2005, Gliocladium (Seifert et al., 2000b), Graphium (Okada et al., 1998(Okada et al., , 2000, Myrothecium, Papulospora, Penicillium, Phialophora, Selenosporella, Sequicillium, Sporothrix, Stigmina, Stilbella and Verticillium (Seifert et al., 2000a, b). The generic names of paraphyletic or polyphyletic anamorphs have been used as unitalicized, descriptive nouns and in a monomorphic, form-sense (Seifert et al., 2000a, b). ...
This thesis investigates the taxonomic utilities of DNA sequence data in
selected groups of anamorphic ascomycetes. The historical practice and limitations
of the dual classification system are reviewed in light of recent molecular
phylogenetic studies.
The morphocentric classification scheme for Sporidesmium and
morphologically similar fungi was tested using a multi-gene phylogenetic approach.
The sporidesmium-like taxa are not monophyletic and are found to be
phylogenetically associated with members of the Dothideomycetes and
Sordariomycetes. Morpho-taxonomic characters, such as conidial septation,
presence or absence of distinct conidiophores, and the type of conidiophore
proliferation have undergone convergent evolution. These anamorphic characters are,
therefore, not significant in the phylogeny-based classification of sporidesmium-like
taxa.
The taxonomy of Diplococcium and Spadicoides was also revisited based on
phylogenetic analyses of partial ribosomal DNA and RNA polymerase II second
largest subunit (RPB2) gene sequence data. Phylogenies indicate that both
Diplococcium and Spadicoides are polyphyletic and conidial catenation is not a
reliable phylotaxonomic character. The diplococcium-like taxa are related to the
Dothideomycetes and Leotiomycetes. Members of Spadicoides are distributed in
Pleosporaceae (Dothideomycetes) and Sordariomycetidae (Sordariomycetes). Two
spadicoides-like genera, Paliphora and Polyschema are related to Chaetosphaeriales
(Sordariomycetes) and Pleosporales (Dothideomycetes), respectively.
Colletotrichum capsici is characterised and epitypified based on morphomolecular
characters. The type specimen of Colletotrichum capsici is in relatively
good condition, but could not provide viable cultures necessary to obtain DNA
sequence data. Fresh specimens of this species were, therefore, collected from chilli
fruit (Capsicum frutescens) in the proximity of the original location as stated in the
protologue. An epitype for the name Colletotrichum capsici is designated using
living cultures in order to stabilise the application of the species name. Multi-gene
phylogenies suggest a close phylogenetic relationship of the epitype with strains of
Colletotrichum capsici from Thailand. Future studies, however, are needed to test
this hypothesis as species-delineation in Colletotrichum is still unresolved.
Investigating the phylogenetic history of some anamorphic taxa has provided
insights into the current morphocentric classification schemes. This thesis supports
the view that many of the anamorphic taxa are derived from polyphyletic lineages.
Molecular and other biological data need to be incorporated to refine the
morphology-based classification systems of anamorphic taxa.
Examination of senescent culms of monocotyledons in Hong Kong and India
has revealed four interesting taxa. Oxydothis bambusicola sp. nov. and
Pseudohalonectria miscanthicola sp. nov. – teleomorphic fungi with unknown
anamorphs – are described from graminaceous hosts in Hong Kong. Massariothea
themedae, a graminicolous anamorphic taxon collected from Kudremukh National
Park in India, is re-described and shown to have multi-locular pycnidia and 4–7-
distoseptate conidia. Oxydothis oraniopsis is reported from decaying fronds of a
palm as the first record of Oxydothis from India.
... Recent molecular phylogenetic studies have confirmed polyphyly/ paraphyly of many of well-recognised anamorphic genera and species, whose classification is subject to further refinement. Prominent examples include: Acremonium (Glenn et al., 1996); Chalara (Paulin and Harrington, 2000; Paulin et al., 2002; Fernández et al., 2006), Cryptococcus (Fell et al., 2000; Scorzetti et al., 2002), Dendrotrichum (Schroers, 2000), Fusarium (Rossman et al., 1999; Rossman, 2000), Geosmithia (Kolarik et al., 2005), Gliocladium (Seifert et al., 2000b), Graphium (Okada et al., 1998), Myrothecium, Papulospora, Penicillium, Phialophora, Selenosporella, Sequicillium, Sporothrix, Stigmina, Stilbella and Verticillium (Seifert et al., 2000a). The generic names of paraphyletic or polyphyletic anamorphs have been used as unitalicized, descriptive nouns and in a monomorphic, form-sense (Seifert et al., 2000a, b). ...
2007). Impact of DNA sequence-data on the taxonomy of anamorphic fungi. Fungal Diversity 26: 1-54. Fungal systematics is an essential part of biological research especially in the context of its ecological and economic implications. The classification of pleomorphic and non-pleomorphic anamorphs, however, is unsettled, which can be attributed to the historical practice of the dual nomenclature/classification system. This paper reviews the historical establishment and limitations of the dual system of classification, and narrates the possible utilities of DNA sequence-data in developing a system of classification based on evolutionary relationships. The dual classification system is a failed hypothesis. DNA sequence-data are now routinely used to link anamorphs with a holomorph and to provide phylogenetic placement for anamorphs with unknown teleomorphs. Emerging phylogenetic and nomenclatural scenarios in the Botryosphaeriales, Chaetosphaeriales, Fusarium graminearum, pestalotiopsis-like anamorphs, and the Mycosphaerella complex are illustrated to indicate potential nomenclatural and taxonomic complexities associated with the dual nomenclature/classification system. The mycological community has a daunting task of developing a system of classification that fulfils the needs of diverse taxonomic users. Molecular characters and tools are, undoubtedly, an indispensable part of fungal systematics.
... The SSU region was amplified with primers NS1 and NS24 and sequenced using primers NS1-NS4, NS6, NS24 (White et al. 1990;Gargas et al. 1992). The components for the PCR were used as described by Schroers (2000). The PCR program was 60 s at 94 °C (initial denaturation); 35 cycles of 35 s at 94 °C (denaturation), 50 s at 55 °C (annealing), and 120 s at 72 °C (elongation); and 6 min at 72 °C (final elongation) followed by chilling to 4 °C. ...
Over 200 new sequences are generated for members of the genus Acremonium and related taxa including ribosomal small subunit sequences (SSU) for phylogenetic analysis and large subunit (LSU) sequences for phylogeny and DNA-based identification. Phylogenetic analysis reveals that within the Hypocreales, there are two major clusters containing multiple Acremonium species. One clade contains Acremonium sclerotigenum, the genus Emericellopsis, and the genus Geosmithia as prominent elements. The second clade contains the genera Gliomastixsensu stricto and Bionectria. In addition, there are numerous smaller clades plus two multi-species clades, one containing Acremonium strictum and the type species of the genus Sarocladium, and, as seen in the combined SSU/LSU analysis, one associated subclade containing Acremonium breve and related species plus Acremonium curvulum and related species. This sequence information allows the revision of three genera. Gliomastix is revived for five species, G. murorum, G. polychroma, G. tumulicola, G. roseogrisea, and G. masseei. Sarocladium is extended to include all members of the phylogenetically distinct A. strictum clade including the medically important A. kiliense and the protective maize endophyte A. zeae. Also included in Sarocladium are members of the phylogenetically delimited Acremonium bacillisporum clade, closely linked to the A. strictum clade. The genus Trichothecium is revised following the principles of unitary nomenclature based on the oldest valid anamorph or teleomorph name, and new combinations are made in Trichothecium for the tightly interrelated Acremonium crotocinigenum, Spicellum roseum, and teleomorph Leucosphaerinaindica. Outside the Hypocreales, numerous Acremonium-like species fall into the Plectosphaerellaceae, and A. atrogriseum falls into the Cephalothecaceae.
... Sequencing of the LSU of rDNA, a sensitive indicator of major clade relationships within the order Hypocreales (16,41,44,50,52), indicates that C. lichenicola and A. falciforme are members of the F. solani clade. They are not the first morphologically divergent anamorphs shown to be associated with the F. solani clade: O'Donnell (41) showed, using sequencing of the LSU, internal transcribed spacer, and elongation factor 1␣ sequences, that members of the ascomycetous genus Neocosmospora, which have unnamed anamorphs that produce no macroconidia and that otherwise resemble a microconidial state of Fusarium, are also nested deeply within the F. solani clade. ...
An emerging pattern of similarity in medical case reports led to a project to compare the phylogenetic affinities of two well-known
tropical fungal opportunistic pathogens, Cylindrocarpon lichenicola and Acremonium falciforme, to members of the Fusarium solani species complex. C. lichenicola and A. falciforme, despite their deviating conidial morphologies, were shown via sequencing of the ribosomal large subunit to be well instituted
within a clade mainly consisting of typical F. solani strains and other species until recently considered variants of F. solani. The original name Fusarium lichenicola C. B. Massalongo is reestablished, and the new combination F. falciforme is made. Recognition of these species as fusaria is necessary for correct interpretation of current and future molecular
diagnostic tests. Reevaluation of species morphology in light of the molecular findings showed that certain features, especially
elongate filiform conidiophores with integrated terminal phialides, facilitate correct microscopic classification of these
atypical Fusarium species. There is a strong and underrecognized overlap in the spectra of cases caused by members of the F. solani clade, particularly ocular infections, mycetomas, and, in the neutropenic host, disseminated and other serious systemic infections.
A novel synthesis of case reports shows that patients from areas with warm climates may develop a distinctive fusarial intertrigo
caused by F. solani, Fusarium lichenicola, or Fusarium oxysporum.
... Nevertheless, we conclude that ' N.' inventa is probably a synonym of S. keithii. That Stephanonectria is a member of the Bionectriaceae in the Hypocreales was also established by a sequence of the large subunit of rDNA (GenBank AF210671 ; Schroers 2000). The relationships of the families of the Hypocreales have been studied in detail by Rossman et al. (2001) and Zhang & Blackwell (2002). ...
The monotype species of the genus Verticillium, Verticillium tenerum, is a synonym of the older name Sporotrichum luteo-album. Its purported teleomorph connection with 'Nectria' inventa is refuted and the preserved specimens of that species are considered as probably identical with Stephanonectria keithii (Bionectriaceae). V. luteo-album takes a unique position in the Glomerella clade of ascomycetes, as sister of the Verticillium-Plectosphaerella clade, which comprises plant-pathogenic species. V. luteo-album is not closely related to V. dahliae and its relatives, which are also situated in this clade. Conservation of the name Verticillium with V. dahliae as conserved type will be necessary to retain this generic name for the plant-pathogenic Verticillium species. In anticipation of this conservation, the new combination Acrostalagmus luteo-albus (syn. Sporotrichum luteo-album) is made.
... Our data from a broad sampling of Tubeufia species including the type species and associated anamorphs should facilitate future investigations of whether Thaxteriella or Acanthostigma and Tubeufia could be recircumscribed as monophyletic genera. For some fungi including Mycosphaerella (Crous et al 2001) and Calonectria (Rossman et al 1999, Rossman 2000, Schroers 2000) anamorphic genera could be delineated so that they correlated with phylogenetic groups. In Tubeufia establishing phylogenetically based anamorphic genera will be difficult. ...
Three genera of asexual, helical-spored fungi, Helicoma, Helicomyces and Helicosporium traditionally have been differentiated by the morphology of their conidia and conidiophores. In this paper we assessed their phylogenetic relationships from ribosomal sequences from ITS, 5.8S and partial LSU regions using maximum parsimony, maximum likelihood and Bayesian analysis. Forty-five isolates from the three genera were closely related and were within the teleomorphic genus Tubeufia sensu Barr (Tubeufiaceae, Ascomycota). Most of the species could be placed in one of the seven clades that each received 78% or greater bootstrap support. However none of the anamorphic genera were monophyletic and all but one of the clades contained species from more than one genus. The 15 isolates of Helicoma were scattered through the phylogeny and appeared in five of the clades. None of the four sections within the genus were monophyletic, although species from Helicoma sect. helicoma were concentrated in Clade A. The Helicosporium species also appeared in five clades. The four Helicomyces species were distributed among three clades. Most of the clades supported by sequence data lacked unifying morphological characters. Traditional characters such as the thickness of the conidial filament and whether conidiophores were conspicuous or reduced proved to be poor predictors of phylogenetic relationships. However some combinations of characters including conidium colour and the presence of lateral, tooth-like conidiogenous cells did appear to be predictive of genetic relationships.
A new disease recently was discovered in begonia elatior hybrid (Begonia × hiemalis) nurseries in The Netherlands. Diseased plants showed a combination of basal rot, vein yellowing and wilting and the base of collapsing plants was covered by unusually large masses of Fusarium macroconidia. A species of Fusarium was isolated consistently from the discolored veins of leaves and stems. It differed morphologically from F. begoniae, a known agent of begonia flower, leaf and stem blight. The Fusarium species resembled members of the F. oxysporum species complex in producing short monophialides on the aerial mycelium and abundant chlamydospores. Other phenotypic characters such as polyphialides formed occasionally in at least some strains, relatively long monophialides intermingled with the short monophialides formed on the aerial mycelium, distinct sporodochial conidiomata, and distinct pungent colony odor distinguished it from the F. oxysporum species complex. Phylogenetic analyses of partial sequences of the mitochondrial small subunit of the ribosomal DNA (mtSSU rDNA), nuclear translation elongation factor 1α (EF-1α) and β-tubulin gene exons and introns indicate that the Fusarium species represents a sister group of the F. oxysporum species complex. Begonia × hiemalis cultivars Bazan, Bellona and Netja Dark proved to be highly susceptible to the new species. Inoculated plants developed tracheomycosis within 4 wk, and most died within 8 wk. The new taxon was not pathogenic to Euphorbia pulcherrima, Impatiens walleriana and Saintpaulia ionantha that commonly are grown in nurseries along with B. × hiemalis. Inoculated plants of Cyclamen persicum did not develop the disease but had discolored vessels from which the inoculated fungus was isolated. Given that the newly discovered begonia pathogen is distinct in pathogenicity, morphology and phylogeny from other fusaria, it is described here as a new species, Fusarium foetens.
Twenty-two fungi of the family Bionectriaceae (Hypocreales, Ascomycota), collected from forests in Taiwan are reported, including Bionectria byssicola, B. compactiuscula, B. grammicospora, B. ochroleuca, B. parviphialis, B. pseudostriata, B. verrucispora, Hydropisphaera ciliata, H. cf. cyatheae, H. peziza, H. suffulta, H. cf. rufofusca, Ijuhya parilis, Ijuhya sp., Nectriella cf. luteola, Nectriopsis cupulata, N. lasiodermopsis, N. sibicola, Ochronectria cf. calami, Stephanonectria keithii, Stilbocrea gracilipes and S. macrostoma. Most of them were found on recently dead broad-leaf trees. All of these species are newly recorded in Taiwan. A dichotomous key to these species is given.
Species of the genus Bionectria (Hypocreales, Bionectriaceae) with anamorphs in Clonostachys are reviewed. Bionectria is distinct from other genera of the Bionectriaceae in overall shape and septation of the ascospores, ascus morphology, ecology, and, in particular, characters of the anamorph. Several other characters of the ascomata may differ from those seen in other genera of the Bionectriaceae as well but none of these is consistently formed in all Bionectria species. The understanding of this genus necessitates emphasis on character patterns rather than single features, because certain characters may overlap with those of other nectrioid taxa. Bionectria forms a monophyletic clade based on analyses of the partial large subunit of the ribosomal DNA (LSU rDNA). The genus includes destructive mycoparasites, some of which are used as biocontrol agents of fungal plant pathogens, as well as species with other substrate associations. The teleomorphs of Bionectria are classified in the six newly distinguished subgenera Bionectria, Zebrinella, Astromata, Myronectria, Epiphloea, and Uniparietina, based on stroma morphology, stroma-perithecium wall interface structure, perithecial wall anatomy, habit of the perithecia on the natural substratum, and ascospore ornamentation and septation. Some but not all of the morphologically delimited subgenera are paraphyletic based on sequences of the internal transcribed spacer regions of the rDNA (ITS rDNA) and a portion of the β-tubulin gene (tub2). The anamorphs of Bionectria are classified in Clonostachys. After reinterpretation of some characters, heightened emphasis on overall character patterns, consideration of transition series within particular character states, and consideration of the appearance of colonies both on the natural substratum and in pure culture, Clonostachys is broadly delimited to include anamorphs formerly classified in Verticilliwn, Gliocladium, Acrostalagmus, Sesquicillium, Spicaria, Dendrodochium, Clonostachyopsis, Verticilliodochium, Gliocladochium, and Myrothecium. All taxa of Bionectria are united by phenotypic characters of the anamorph such as penicillate conidiophores, conidia held in imbricate columns, and predominantly more or less curved conidia with mostly laterally displaced hila. These characters are rare or not formed in other genera of the Bionectriaceae. Conidiomata, intercalary phialides, conidiophore dimorphism, and conidial mass colour are variable within Bionectria, although to a certain extent they may reflect subgeneric affinities. In Bionectria / Clonostachys 44 holomorphic or anamorphic species are distinguished based on morphological discontinuities. Based on inferences from ITS rDNA and tub2 sequences, most of the species form monophyletic units. In few cases paraphyletic clades are accepted as species. In two species, C. rosea and C. solani, infraspecific forms are proposed to segregate strains with either white to pale orange or green conidial masses. The following taxa are accepted, newly combined (bold letters, comb. nov.), or newly described (bold letters: subgen. nov., sp. nov., or stat. nov): Subgenus BIONECTRIA: B. apocyni/C. macrospora comb. nov. - B. aureofulvella sp. nov./C. aureofulvella stat. nov. - B. byssicola/C. byssicola stat. nov. - B. capitata sp. nov./C. capitata stat. nov. -B. compactiuscula sp. nov./C. compactiuscula - B. kowhaii comb. nov./C. kowhaii stat. nov. - B. oblongispora sp. nov./C. oblongispora stat. nov. - B. ochroleuca/C. rosea -C. rosea f. catenulata stat. nov. - B. zelandiaenovae sp. nov./C. zelandiaenovae stat. nov. - B. pseudochroleuca sp. nov./C. pseudochroleuca stat. nov. - B. pseudostriata sp. nov./C. pseudostriata stat. nov. - B. ralfsii comb. nov./C. ralfsii stat. nov. -B. samuelsii sp. nov./C. samuelsii stat. nov. - B. solani comb. nov./C. solani comb. nov. - C. solani f. nigrovirens stat. nov. - B. sporodochialis sp. nov./C. sporodochialis stat. nov. - B. tonduzii/C. ?macrospora - B. verrucispora sp. nov./C. verrucispora stat. nov. - C. agrawalii comb. nov. - C. divergens sp. nov. - C. rhizophaga sp. nov. -C. rogersoniana sp. nov. - Subgenus ZEBRINELLA subgen. nov.: B. grammicospora comb. nov./C. grammicospora stat. nov. - B. grammicosporopsis comb. nov./C. grammicosporopsis stat. nov. - B. levigata sp. nov./C. levigata stat. nov. - B. lucifer comb. nov./C. lucifer stat. nov. - B. subquaternata comb. nov./C. subquaternata stat. nov. -C. chlorina sp. nov. - C. intermedia sp. nov. - Subgenus ASTROMATA subgen. nov.: B. epichloë comb. nov./C. epichloë stat. nov. - B. parva sp. nov./?C. miodochialis - C. miodochialis sp. nov. - Subgenus MYRONECTRIA subgen. nov.: B. pityrodes comb. nov./C. pityrodes stat. nov. - Subgenus EPIPHLOEA subgen. nov.: B. gibberosa sp. nov./C. cf. setosa - B. impariphialis comb. nov./C. impariphialis comb. nov. - B. lasiacidis comb. nov./C. lasiacidis stat. nov. - B. parviphialis comb. nov./C. pseudosetosa comb. nov. - B. rossmaniae sp. nov./C. rossmaniae stat. nov. - B. sesquicillii comb. nov./C. sesquicillii stat. nov. - B. setosa sp. nov./C. setosa comb. nov. - B. tornata comb. nov./C. asymmetrica comb. nov. - C. candelabrum comb. nov. - C. phyllophila sp. nov. - Subgenus UNIPARIETINA subgen. nov.: B. aurantia - B. coronata comb. nov./C. buxi comb. nov.
Specimens of the Bionectriaceae and Nectriaceae from tropical China on deposit in the Mycological Herbarium, Institute of Microbiology, Chinese Academy of Sciences were re-examined. Fifteen species were identified. Among them, Cosmospora damingshanica and Nectriopsis hongkongensis are described as new species. The new combinations Bionectria mellea, Cosmospora effusa, and Cosmospora nummulariae are proposed.
Based on the result of morphological and the phylogenetic analyses, three Bionectria (Bionectriaceae: Hypocreales) species are added to the mycobiota of Japan. Among them, one found in Okinawa and Kagoshima
Prefectures is described as a new species, Bionectria pseudostriatopsis (anamorph: Clonostachys pseudostriatopsis). The other two, B. grammicospora and B. sporodochialis, are new records from Japan. Additional distribution records are given for Bionectria species hitherto known in Japan.
A new disease recently was discovered in begonia elatior hybrid (Begonia × hiemalis) nurseries in The Netherlands. Diseased plants showed a combination of basal rot, vein yellowing and wilting and the base of collapsing plants was covered by unusually large masses of Fusarium macroconidia. A species of Fusarium was isolated consistently from the discolored veins of leaves and stems. It differed morphologically from F. begoniae, a known agent of begonia flower, leaf and stem blight. The Fusarium species resembled members of the F. oxysporum species complex in producing short monophialides on the aerial mycelium and abundant chlamydospores. Other phenotypic characters such as polyphialides formed occasionally in at least some strains, relatively long monophialides intermingled with the short monophialides formed on the aerial mycelium, distinct sporodochial conidiomata, and distinct pungent colony odor distinguished it from the F. oxysporum species complex. Phylogenetic analyses of partial sequences of the mitochondrial small subunit of the ribosomal DNA (mtSSU rDNA), nuclear translation elongation factor 1α (EF-1α) and β-tubulin gene exons and introns indicate that the Fusarium species represents a sister group of the F. oxysporum species complex. Begonia × hiemalis cultivars Bazan, Bellona and Netja Dark proved to be highly susceptible to the new species. Inoculated plants developed tracheomycosis within 4 wk, and most died within 8 wk. The new taxon was not pathogenic to Euphorbia pulcherrima, Impatiens walleriana and Saintpaulia ionantha that commonly are grown in nurseries along with B. × hiemalis. Inoculated plants of Cyclamen persicum did not develop the disease but had discolored vessels from which the inoculated fungus was isolated. Given that the newly discovered begonia pathogen is distinct in pathogenicity, morphology and phylogeny from other fusaria, it is described here as a new species, Fusarium foetens.
Widespread morbidity and mortality of Juglans nigra has occurred in the western USA over the past decade. Tree mortality is the result of aggressive feeding by the walnut twig beetle (Pityophthorus juglandis) and subsequent canker development around beetle galleries caused by a filamentous ascomycete in genus Geosmithia (Ascomycota: Hypocreales). Thirty-seven Geosmithia strains collected from J. californica, J. hindsii, J. major and J. nigra in seven USA states (AZ, CA, CO, ID, OR, UT, WA) were compared with morphological and molecular methods (ITS rDNA sequences). Strains had common characteristics including yellowish conidia en masse, growth at 37 C and absence of growth on Czapek-Dox agar and belonged to a single species described here as G. morbida. Whereas Geosmithia are common saprobes associated with bark beetles attacking hardwoods and conifers worldwide, G. morbida is the first species documented as a plant pathogen.
Cladistic analysis of partial sequences (840 nucleotide positions) from the nuclear encoded small subunit ribosomal DNA was performed to infer the higher taxonomic placement of the Clavicipitales within unitunicate perithecial ascomycetes. Two major classifications exist concerning the placement of this order of ascomycetes; one places it as a sister group to the Hypocreales and the other, as a member of or a near relative to the Xylariales. A strict consensus of 10 equally most parsimonious trees was in agreement with the placement of the Clavicipitales as a monophyletic sister group to the Hypocreales; relationships within the Clavicipitales were not fully resolved in the strict consensus. The taxa sampled from the Hypocreales comprised a paraphyletic lineage in the strict consensus. Characters derived from anamorphs, stromata, centrum anatomy and nutritional modes were reviewed with respect to their level of congruence with the results inferred from the molecular data.
The structure and development of perithecia in Eve collections of Epichloe from Europe and North America were studied. Perithecia in early stages of development are oblong to ovate in overall shape. Dichotomously branched paraphyses form on the bottom and sides of the inner wails of the perithecial primordium. As the ovate primordium expands, a mound of ascogenous mycelium develops in its base. As asci develop from the ascogenous mound, paraphyses proximal to asci evanesce and no paraphyses are observable within the cluster of asci. In E. amarillans and E. baconii paraphyses are converted into pseudoparenchyma-like tissues, while in E. typhina paraphyses remain filamentous until they evanesce. Ascospore development is seen to differ among all three species of Epichloe. The development and structure of the Epichloe centrum are compared to those of the Nectria and Xylaria types. It is apparent that a distinct type of centrum is present in Epichloe, and perhaps all of the Clavicipitaceae. It is proposed that the Epichloe type centrum may represent a key feature for distinguishing the Clavicipitaceae from the Hypocreaceae or other groups of pyrenomycetes.
The nucleotide sequence of the internal transcribed spacer （ITS） regions of the ribosomal DNA including the 5.8S rRNA gene and the 5' end of the 28S rRNA gene have been determined for 19 species in 10 genera of the powdery mildew fungi in order to analyze their phylogenetic relationship. These fungi were divided into two large groups based on the nucleotide length of the ITS regions, and this grouping was in line with that based on the morphological characters of the anamorphic stage rather than the teleomorphic stage. Although the variable ITS sequences were often ambiguously aljgned, conserved sites were also found. Thus, a neighbor－joining tree was constructed using the nucleotide sequence data of the conserved sites of theITS regions, the 5.8S rRNA gene, and the 5' end of the 28S rRNA gene．The phylogenetic tree displayed the presence of four groups in the powdery mildews, Which were distinguished by their morphology and/or host ranges. In the ITS2 region, the presence of a common secondary structure having four hairpin domains was suggested, in spite of the highly variable nucleotide sequences of this region. The predicted secondary structure was supported by the compensatory mutations as well as compensatory conserved sequence and high G＋C content in the predicted stem regions.
Phylogenetic relationships of several species within the Fusarium solani-complex were investigated using characters from the nuclear ribosomal DNA. Genetic variation within 24 isolates, including 5 soybean sudden death syndrome (SDS) strains, was assessed using rDNA sequence data and restriction fragment length polymorphic markers. By these techniques, the causal agent of soybean SDS was identified as F. solani f. sp. phaseoli. In separate cladistic analyses, Plectosphaerella cucumerina and Nectria cinnabarina or F. ventricosum were used for rooting purposes. Monophyly of the F. solani-complex was strongly supported by bootstrap and decay analyses. Parsimony analysis indicates that this complex is composed of a number of phylogenetically distinct species, including Neocosmospora vasinfecta, F. solani f. sp. phaseoli, and biological species designated as MPI, MPV, and MPVI of N. haematococca. The results demonstrate complete congruence between biological and phylogenetic species within the N. haematococca-complex. In addition, DNA sequence data were used to design a PCR primer pair which could specifically amplify DNA from isolates of the SDS pathogen from infected plants.
A new unispecific genus of the Bionectriaceae, Stephanonectria, is described for Nectria keithii. Stephanonectria is characterised by brown, smooth perithecia that do not change colour in KOH and by a peculiar crown-like structure around the ostiole. The ascospores are covered with short striae that are more or less parallel with the long axis of the spore. The ascospores of different collections vary considerably in length but the differences are not indicative of infraspecific differences or particular geographical patterns. The anamorph shows features typical of several genera, and is here identified as Myrothecium-like. Perithecia of Stephanonectria keithii have been found on dead parts of Brassica sp. and various dead woody substrata in Europe, New Zealand, and possibly also in tropical regions. The anamorph has been isolated from European soil as well.
A new genus in the Hypocreales, Leuconectria, is described for Pseudonectria clusiae based on its unique perithecial wall anatomy and the anamorph Gliocephalotrichum bulbilium produced from single ascospores of L. clusiae. The teleomorph had previously been placed in Pseudonectria, a genus defined for Nectria-like species with nonseptate ascospores. Pseudonectria is redefined based on the type species P. rousseliana and its anamorph Volutella buxi. Pseudonectria rousseliana causes a disease of boxwood (Buxus sempervirens) in the Buxaceae. The two other species included in Pseudonectria, P. coronata and P. pachysandricola, also occur on members of the Buxaceae. All three species are described and illustrated, and a key to species is provided.
A key to the five species of Nectria that develop on sporangia or aethalia of Myxomycetes and a description of each species and its imperfect state (when known) are given. Two new species, Nectria hirsuta and Nectria sporangiicola, are described. Nectria myxomyceticola nom. nov. (Hypomyces exiguus Pat.), Nectria candicans (Plowr.) comb. nov. (Hypomyces candicans Plowr.), Acremonium fungicola (Sacc.) stat. nov. (Diplosporium album var. fungicolum Sacc.), and Stilbella tomentosa var. ovalispora (A. L. Smith) Rogerson comb. nov. (Stilbum tomentosum var. ovalispora A. L. Smith) are proposed. Four species have been grown in culture from solitary ascospores and their characteristics in culture are described. A discussion of the genera Nectriopsis Maire and Hyphonectria (Sacc.) Petch is included. The haploid chromosome number of 4 is reported for Nectria violacea and N. candicans.
Because the common soil fungus and mycoparasite Gliocladium roseum differs from the type species of Gliocladium, G. peniclllioides, in morphology ecology, teleomorph, and DNA sequence data, it is classified in a separate genus, Clonostachys. Penicillium roseum is the oldest available name for G. roseum and is recombined as C. rosea. Penicillium roseum described from potato in Germany, is neotypified by a conidial isolate originating from a fungal substratum in European soil. By choosing this strain as neotype for P. roseum the epithet is formally linked to the common soil fungus used in the biocontrol of fungal plant pathogens. The anamorph of Bionectria ochroleuca (Hypocreales) is morphologically indistinguishable from C. rosea; both morphs are redescribed. Bionectria is generically distinct from Nectria s. s. and is the appropriate genus for species of the Nectria ochroleuca group. The anamorph genus Gliocladium s. s. is associated with teleomorphs in Sphaerostilbella and Hypocrea series Pallidae. With the separation of Clonostachys from Gliocladium and Bionectria from Nectria the generic classification reflects natural relationships. A generic circumscription is proposed for Clonostachys and compared with Gliocladium. Nectriopsis sporangiicola and Roumegueriella rufula are related to Bionectria but have distinct Gliocladium-like anamorphs. Based on morphological features, Rhopalocladium myxophilum gen. et sp. nov. is proposed for the anamorph of N. sporangiicola. The anamorph of Roumegueriella rufula is generally found in association with the teleomorph and is referred to as Gliocladium-like.
The generic names Tricholeconium, Periolopsis, Actinostilbe, Kutilakesa and Kutilakesopsis are accepted as synonyms of Sarcopodium. Two species of Sarcopodium with 1-septate conidia are re-described — 5. vanillae (Petch) comb.nov. (syn. Actinostilbe vanillae Petch), and S. macalpinei (Agnihoth. & Barua) comb.nov. (syn. Kutilakesopsis macalpinei Agnihoth. & Barua). They differ in shape and size of sporodochial setae and in size of conidia.
Nine species ofNectria are described or redescribed. Ascospores of all are colorless and striates; their perithecia are orange and do not become
red in KOH. Three groups of species are represented. One group includesNectria grammicospora, N. cf.grammicospora, N. subquaternata, and the new species:N. grammicosporopsis, N. lucifer, andN. neogrammicospora. A second group includes the new speciesN. chlorogloea andN. septomyrotheciae. The third group is represented by the single new speciesN. dacryocarpa. The life-cycles of these species are described. Anamorphs ofN. grammicospora, N. grammicosporopsis, N. lucifer, andN. subquaternata are species ofClonostachys. The anamorph, ofN. neogrammicospora isAcremonium- orCephalosporiopsis-like in having monophialidic conidiophores and phragmosporous conidia, and that ofN. cf.grammicospora isAcremonium-like with amerosporous conidia. The anamorphs ofN. chlorogloea andN. septomyrotheciae have green conidia. The anamorph ofN. chlorogloea isMyrothecium sp.; its conidia are unicellular and the conidioma is a synemma. The anamorph ofN. septomyrotheciae isSeptomyrothecium cf.uniseptatum; its conidioma is a sporodochium and the conidia are bicellular. The new genus and speciesDacryoma alba are described for the anamorph ofN. dacryocarpa. All of these fungi are pantropical or Australasian in distribution.