Mycol. Res. 100 (3): 343-348 (1996) Printed in Great Britain 343 Three new species of Amauroascus from tropical regions J. CANO1, P. VIDAL1, J. GUARRO1, R. F. CASTANEDA RUIZZ A N D CH. DE VROEY3 ' Unifafde Microbiologia, Faculfaf de Medicina i Ciencies de la Saluf, Unioersifaf Rovira i Virgili, 43201-Reus, Tarragona, Spain 21nsfifufo de InvesfigacionesFundarnenfales en Agriculfura Tropical 'Alejandro Humboldf' (INIFAT), Ciudad de la Habana, Cuba Laborafoy for Mycology, Instifufe of Tropical Medicine 'Prince Leopold', Nafionalesfraat 155, B-2000 Antwerpen, Belgium Arnauroascw cubensis, A. fropicalis and A. bumdensis, three new keratinophilic fungi from tropical soils, are described and illustrated. Amauroascus currently comprises eight species (Currah, 1985; Cano & Guarro, 1989; Guarro ef al., 1991) all of them with keratinophilic properties. The main features of the genus are the presence of ascomata enclosed by undifferentiated but some- times encrusted peridial hyphae, and ascospores which are mostly spherical, pigmented, and ornamented with a definite pattern of pronounced, regular or irregular puncta and ridges. Close relationships with some species of Auxarfhron G. F. ON & Kuehn and Nannizziopsis Currah are known to exist. During a survey of keratinophilic fungi from tropical regions three interesting species of Amauroascus were recovered. Two of them, A fropicalis and A. bumdensis, grew well in artificial culture and the connexions with their anamorphs were accomplished. The third species, A. cubensis, failed to grow on all the assayed culture media and under different conditions; therefore, its description is based ex- clusively on ascomata fruiting on horse hair bait. These species differ from the others in the genus and are herein described as new. Amauroascus cubensis Cano, Guarro & R. F. Castaiieda, sp. nov. (Figs 1-5) Etym.: Latin: cubensis = from Cuba, referring to the type locality Ascomafa discreta, plus minusve globosa, 200-300 ~lm dim., alba. Peridium ex crassis hyphis anastomosantibus efferens et reticulum efformans, hyphis 2.5-3.2 pm latis et aspemlatis; septatis, hyalinis. Asci globosi, octospori, 22-24 pm diarn., evanescentes. Ascosporae pallide bmnneae, unicellulares, globosae, 8-9 Dm dim., regulares et foveolato-reticulatae. Anamorphosis ignota. Species keratinophilica. Holofypus: ex solo, in collectione fungorum IMI 364812, Egham, Britannia depositus est. Material examined: Amauroascus cubensis FMR 4261 (isotype),garden soil, Ciknaga de Zapata, Prov. Cienfuegos, Cuba, March 1992, J. Cano. This species developed numerous hyphae on fragments of horse hair deposited on the surface of Petri dishes full of soil. Numerous ascomata were produced by 20-23 d. However, the fungus grew poorly at different temperatures on the culture media tested, i.e. potato dextrose agar (PDA), Phytone yeast agar (PYE), oat meal agar (OA), Sabouraud 1/10 dil+ salts (TK) (Takashio, 1973). Only small colonies with sparse sterile mycelium were produced on these media. The most striking characteristic of A. cubensis is the large size of the ascospores. Those of the other species are less than 6.5 pm diam., with the exception of A. mufafus (QuCl.) Rammeloo (6-8-7 pm). However, A. cubensis and A. mufafus are easily differentiated by the ornamentation of the ascospores, which is regularly punctate-reticulate in the first and venucose-tuberculate in the second. Two strains of A. mufafus were examined (FMR 3708 (Fig. 6) and UAMH 3563). Amauroascus burundensis Vidal, Cano & Guarro sp. nov. (Figs 7, 9-12, 14) Etym.: Latin, burundensis = from Burundi, refemng to the type locality Anamorph: Malbranchea sp. Ascomafa discreta, plus minusve globosa, 200-600 J.WI diam., alba. Peridium ex crassis hyphis anastomosantibus efferens et reticulum efformans, hyphis 1.5-2.5 prn latis et aspemlatis, septatis, hyalinis vel pallide luteis. Asci subglobosi, octospori, 7-10 ~ 6 - 7 Urn, evanescentes. Ascosporae pallide luteae, unicellulares, globosae, 3.5-4 pm diam., regulare-reticulatae. Anamorphosis: Conidia intercalaria, solitaria, hyalina, plus rninusve Ascomafa globose, white, 200-300 pm in diam. Peridial hyphae cylindrica, 3-6 x 1.5-2 (2.5) pm, tenuitunicata, aspemlata. Species keratinophilica. hyaline, constricted at the septa, smooth or slightly asperulate, 2.5-3.2 urn wide. thin-walled, branched and anastomosed, Holotypus: ex solo, in collectione fungorum IMI 364811, ham, - - scarcely differentiated. Asci globose, 8-spored, 22-24 pm Britannia, depositus est. diam., evanescent. Ascospores spherical, one-celled, light brown, Ascomata globose, white, 200-600 pm diam. Peridial hyphae brown in mass, 8-9 um dim., thick-walled, with h e l y and hyaline to light yellow, septate, smooth or slightly asperulate regularly punctate-reticulate walls. with light microscopy, asperulate under SEM, 1.5-2.5 pm Anamorph unknown. wide, thin-walled, branched and anastomosed, scarcely