Mycol. Res. 101 (12) : 1531–1534 (1997) 1531 Printed in the United Kingdom Two new coelomycetes with appendaged conidia on stems of eucalypts from Australia Z I Q I N G Y U A N1, 2 A N D C A R O L I N E M O H A M M E D1, 2 " Department of Agricultural Science, University of Tasmania, GPO Box 252-54, Hobart, Tas. 7001, Australia # CSIRO, Forestry and Forest Products, Tasmanian Research Centre, GPO Box 252-12, Hobart, Tas. 7001, Australia Two new coelomycetes with appendaged conidia collected on branches of Eucalyptus species in Tasmania are described, illustrated and compared with closely related taxa. They are Ciliosporella tuberculiformis sp. nov. on E. regnans and Neoplaconema cymbiforme sp. nov. on E. nitens. Fourteen mitosporic fungal species associated with eucalypt stem cankers or dead branches in Tasmania are reported in Yuan & Mohammed (1997 a). Seven of these species are undescribed with the exception of Seiridium papillatum Z. Q. Yuan (Yuan & Mohammed, 1997 b). This paper describes another of the unnamed species and one recently collected coelomycetous fungus, Ciliosporella tuberculiformis and Neoplaconema cymbiforme. Ciliosporella tuberculiformis was collected on Eucalyptus regnans F. Muell. on two occasions at a single locality. Fruit bodies are typically immersed in wart-like swellings on either healthy or dead tissue at the edge of necrotic lesions associated with stem tip dieback (Fig. 4). Neoplaconema cymbiforme was associated with cankers at branch bases of trees in plantations of E. nitens (Deane & Maiden) Maiden with severe Mycosphaerella leaf disease. Both fungi have sufficiently distinctive characteristics to be proposed as new anamorphspecies. This is the first time members of Ciliosporella Petr. and Neoplaconema B. Sutton have been found on eucalypts in the southern hemisphere. Microscopic examination of each specimen was carried out on squash mounts and thin median sections. The material was mounted in Shear’s mounting fluid or lactophenol. Fifty mature conidia were measured for each species, and arithmetic means calculated. The holotypes are deposited in the Herbarium of the Institute for Horticultural Development, Knoxfield, Australia (VPRI). DESCRIPTION AND DISCUSSION Ciliosporella tuberculiformis Z. Q. Yuan & C. Mohammed, sp. nov. (Figs 1–7) Etym. : refers to the association of the fungal fruiting bodies with wart-like swellings of host tissue. Conidiomata caulicola, pycnidialia, immersa, discreta vel gregaria catervatim, globosa vel subglobosa, 125–195 µm lata, 100–175 µm alta, dehiscentia e fissura apicali ; paries 15–20 µm crassus, ad apicem 25–30 µm crassus, e textura angulari parietibus crassis brunnea vel pallide brunneisque compositus. Conidiophora 15 µm longa, stratum intimum telae basalis conidiomatum tegentia, hyalina, ramosa et 1–3- Figs 1–3. Ciliosporella tuberculiformis. Fig. 1. Conidia. Fig. 2. Conidiophores. Fig. 3. Vertical section of conidioma (bar, 20 µm for Figs 1, 2 ; 50 µm for Fig. 3). New coelomycetes on eucalypts 1532 Figs 4–7. Ciliosporella tuberculiformis. Fig. 4. Conidiomata associated with wart-like swellings in necrotic lesions caused by stem tip dieback. Fig. 5. Conidia. Fig. 6. Conidiophores. Fig. 7. Vertical section of conidioma (bar, 2 mm for Fig. 4 ; 25 µm for Figs 5, 6 ; 40 µm for Fig. 7). septata, glabro-tunicata, in muco involuta. Cellulae conidiogenae 5–7±5¬2±5–3 µm, discretae, ampulliformes vel lageniformes, hyalinae, laeves. Conidia 30–45¬3±8–5 µm, unicellularia, hyalina, fusiformia vel naviculata, vulge curvata, basi truncata et apice acuta, laevia, guttulata et granulata ; appendix apicalis cellularis, singularis, attenuata, rostrata vel tubularis, simplex, unicellularis, a corpore conidii non secta, 4±5–7±5 µm longa ; ratione conidii long.}lat. ¯ 7±9 : 1. In ramulis Eucalypti regnantis F. Muell., Florentine Valley, Westfield, Tasmania, Australia, 15 Feb. 1996, Z. Q. Yuan 93 (VPRI 20828), holotypus. Caulicolous. Conidiomata pycnidial, immersed, scattered or gregarious in groups on the upper surface of wart-like swellings of branch tissue, globose to subglobose, small, 125–195 µm wide, 100–175 µm high, dehiscence by a split in the apical wall ; wall 15–20 µm thick, up to 25–30 µm thick at top parts, composed of textura angularis, cells thick-walled, brown, becoming paler and thin-walled toward the conidial hymenium. Conidiophores lining the cavity of the conidioma, hyaline, 1–3-septate, branched, smooth, up to 15 µm long, invested in mucus. Conidiogenious cells discrete, ampulliform to lageniform, hyaline, 5–7±5¬2±5–3 µm. Conidia 30–45¬3±8–5 (mean 38¬4±8) µm, one-celled, hyaline, fusiform to naviculate, mostly curved, with a truncate base and an acute apex, smooth, guttulate and granular ; apex attenuated into a rostrate, tubular, unbranched, cellular appendate (type A, sensu Nag Raj, 1993), not separated from the conidium by a septum, 4±5–7±5 (mean 5) µm long ; mean conidium length}width ratio ¯ 7±9 : 1. On moribund branches of Eucalyptus regnans. Specimens examined : Tasmania, Florentine Valley, Westfield, on E. regnans, 15 Feb. 1996, Z. Q. Yuan 93 (VPRI 20828), holotype ; same locality and host, 22 Sep. 1996, Z. Q. Yuan 296. Ciliosporella was proposed by Petrak (Annales mycologici 25 : 217, 1927), based on the type mitosporic species C. selenospora Petr. So far the genus has remained monotypic (Hawksworth et al., 1995). C. selenospora was described on stems of Trifolium alpestre in Austria and is characterized by fusiform to naviculate, one-celled, hyaline conidia bearing an apical rostrate, tubular, unbranched appendage of type A (sensu Nag Raj, 1993). The fungus collected on eucalypts in Tasmania fits the concept for Ciliosporella given by Nag Raj (1993), even though it is very different from C. selenospora in its host and geographical distribution. Ciliosporella tuberculiformis differs from C. selenospora in that its conidiomata are always associated with wart-like swellings on dying branches of eucalypt and the conidiomatal wall is characteristically thicker at its apex. Conidia in C. tuberculiformis are curved, filled with guttules and granules, whilst those of C. selenospora are straight, without contents, and much smaller (20–29¬2–3 µm for C. selenospora, fide Nag Raj, 1993). Z. Q. Yuan and Caroline Mohammed 1533 Figs 8–10. Neoplaconema cymbiforme. Fig. 8. Conidia. Fig. 9. Conidiophores. Fig. 10. Vertical section of conidioma (bar, 20 µm for Figs 8, 9 ; 150 µm for Fig. 10). Conidial morphology in C. tuberculiformis is also similar to that of Monochaetiella hyparrheniae E. Castell. which has fusiform to naviculate, unicellular conidia bearing an apical appendate of type A (Nag Raj, 1993). M. hyparrheniae, however, has conidiomata of typical acervuli and much wider conidia with a mean conidium length}width ratio of 5±7 : 1. Neoplaconema cymbiforme Z. Q. Yuan & C. Mohammed, sp. nov. (Figs 8–13) Etym. : refers to the naviculate shape of the conidia. Conidiomata caulicola, pseudostromatica, immersa, unilocularia, 400–500 µm diam., paries 12±5–20 µm crassus, e textura angulari 5–8 µm diam. parietibus tenuibusque compositus ; loculus 150–200 µm diam., e pseudoparenchymate texturae intricatae cum hospiti cingulatus. Conidiophora hyalina, 1–2-septata, basi ramosa, glabro-tunicata, in muco involuta. Cellulae conidiogenae 5–12±5¬2±5–4±0 µm, discretae vel integratae, lageniformes vel cylindricae, laeves ; canalis minuta, cum parieti a latere incrassato. Conidia 15±0–21±3¬2±5–4±0 µm, unicellularia, hyalina, tenui- vel crassitunicata, naviculata, ad extrema attenuata, apice obtusa et basi anguste truncata, recta vel raro leviter curvata, appendicem apicalem ferentia ; appendix apicalis cellularis, singularis, attenuata, tubularis, simplex, unicellularis, a corpore conidii secta, 7±5–11±3 µm longa ; ratione conidii long.}lat. ¯ 5±45 : 1. In ramulis Eucalypti nitentis, Basil’s Rd, Ridgley, North Forest Products, Tasmania, Australia, 12 Sep. 1996, D. de Little 297 (VPRI 21090), holotypus. Caulicolous. Conidiomata pseudostromatic, immersed, unilocular, black, ostiolate, 400–500 µm diam. ; wall composed of thin-walled textura angularis (5–8 µm diam.) ; loculi Figs 11–13. Neoplaconema cymbiforme. Figs 11, 12. Conidia. Fig. 13. Vertical section of conidioma (bar, 15 µm for Figs 11, 12 ; 90 µm for Fig. 13). 150–200 µm diam., surrounded by pseudoparenchyma of textura intricata intermixed with host tissue. Conidiophores hyaline, 1–2-septate, branched at the base, smooth-walled, invested in mucus. Conidiogenous cells hyaline, discrete or integrated, lageniform to cylindrical, channel minute but periclinal wall considerably thickened, smooth-walled, 5–12±5¬2±5–4±0 µm. Conidia 15±0–21±3¬2±5–4±0 (mean 16±9¬3±1) µm, unicellular, colourless, thin and smooth-walled, naviculate, tapering towards both ends, with an obtuse apex and a narrow truncate base, straight or occasionally slightly curved, bearing an apical appendage of type A ; appendage arising as a tubular extension of the conidium body and delimited from it by a septum, unbranched, slightly attenuated, flexuous, 7±5–11±3 (mean 9±6) µm long ; mean conidium length}width ratio ¯ 5±45 : 1. On cankered branch of Eucalyptus nitens. Specimens examined : Tasmania, Basil’s Rd, Ridgley, North Forest Products, on E. nitens (Deane & Maiden) Maiden, 12 Sep. 1996, D. de Little (VPRI 21090), holotype. Only a single species, N. napelli (Maire & Sacc.) B. Sutton, is accepted in Neoplaconema (Sutton, 1977 ; Nag Raj, 1993), on stems and branches of Aconitum napellum and A. toxicum from Germany and Romania (Nag Raj, 1993). The conidia of N. napelli are shorter but wider than those of N. cymbiforme, with New coelomycetes on eucalypts a mean conidium length}width ratio of 3±54 : 1 and apical appendages up to 27 µm long ( fide Nag Raj, 1993). Conidial shape, size and apical appendage in N. cymbiforme are similar to those of Mastigosporella hyalina (Ellis & Everh.) Ho$ hn. on leaves of Quercus coccinea (Nag Raj, 1993). Species of Mastigosporella Ho$ hn., however, have pycnidial conidiomata (without surrounding pseudostromatic tissue) and percurrently proliferating conidiogenous cells. Conidia of Mastigosporella do have apical appendages of type A as in Neoplaconema, but they are not separated from the conidium by a septum. The teleomorph of Neoplaconema has never been reported. Some immersed, spherical perithecia were found adjacent to or below the conidiomata of N. cymbiforme in the cankered area of stems of the present collection, but no ascospores were present. The senior author wishes to thank the University of Tasmania and CSIRO Forestry and Forest Products for his scholarship, (Accepted 17 April 1997) 1534 and North Forest Products for partial financial assistance. Dr D. de Little (North Forest Products, Tasmania) sent us one of the specimens examined in the paper and for this we are grateful. REFERENCES Hawksworth, D. L., Kirk, P. M., Sutton, B. C. & Pegler, D. N. (1995). Ainsworth and Bisby’s Dictionary of the Fungi, 8th ed. CAB International : Wallingford. Nag Raj, T. R. (1993). Coelomycetous Anamorphs with Appendage-bearing Conidia. Mycologue Publications : Waterloo, Canada. Sutton, B. C. (1977). Nomenclature and taxonomy of Shanoria, Placonema and Neoplaconema (Sphaeropsidales). Kew Bulletin 31, 461–464. Yuan, Z. Q. & Mohammed, C. (1997 a). Investigation of fungi associated with stem cankers of eucalypts in Tasmania, Australia. Australasian Plant Pathology 26, (In press). Yuan, Z. Q. & Mohammed, C. (1997 b). Seiridium papillatum, a new species (mitosporic fungus) described on stems of eucalypts in Australia. Australian Systematic Botany 10, 69–75.