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Morphological and anatomical features, pigment chemistry, host specifity and culture behav- ior were examined for about 200 strains of the bole- ticolous anamorph genus Sepedonium. A sequence analysis of the internal transcribed spacer region of the nuclear ribosomal RNA genes (including ITS1, 5.8S, ITS2) was performed with 52 of these strains. Phylogenetic trees were generated using neighbor joining and parsimony. The outgroup taxon was Cla- dobotryum varium. Our DNA data indicate a subdivi- sion of the Sepedonium isolates into eight monophy- letic taxa, seven of them assignable to accepted spe- cies. Extensive descriptions are provided for all spe- cies. One species, S. laevigatum, is described as new. An evaluation is presented for the systematic signifi- cance of the characters studied. A morphological key is provided. live as parasites on boletes and bolete relatives (Bo- letales). Distribution of the genus Sepedonium is worldwide. Seven species are generally acknowl- edged, most of them associated with the teleomorph genus, Hypomyces Tul. (including Apiocrea H. Syd.). Five more taxa of Sepedonium have been reported as correlated with boleticolous Hypomyces (Rogerson and Samuels 1989), but are not formally named yet. A modern infrageneric classification of Sepedonium has been developed only recently (e.g., see Rogerson and Samuels 1989). Before that, collections with glo- bose, warty and golden yellow aleurioconidia were generally identified as S. chrysospermum (= S. myco- philum). Petch (1938) and Pieschel (1962) noted considerable variability within S. chrysospermum, which led to the recognition of new taxa, including S. ampullosporum (Damon 1952), S. chalcipori (Hel- fer 1991), and S. microspermum (Besl et al 1998). Approximately 200 isolates of Sepedonium, mostly originating from Germany, but also from the United States and the southern hemisphere, are included in the present study. The isolates comprise all the Eu- ropean species hitherto known. The formation of the teleomorph is rarely observed in Europe; therefore, mostly the characters of the anamorphs were inves- tigated. In a first assay, emphasis was placed on the morphology of aleurioconidia, culture behavior, sub- strate specifity and secondary metabolites. A repre- sentative selection of strains was used for a sequenc- ing approach of a portion of the nuclear ribosomal |
