MOLECULAR SYSTEMATICS OF SOME YEAST-LIKE ANAMORPHS BELONGING TO THE USTILAGINALES AND TILLETIALES

Partial nuclear large subunit ribosomal DNA sequences were analysed fr om species of Entyloma, Itersonilia, Melanotaenium, Microbotryum, Till etiopsis, Tilletiaria, Tilletia, Ustilago and a number of ustilaginace ous anamorphs in order to assess phylogenetic relationships. The resul ts indicate that Tilletiopsis is polyphyletic, comprising four indepen dently derived groups of species. The teleomorphic species Tilletiaria anomala forms a monophyletic group with Tilletiopsis fulvescens, T. f lava and T. minor. Cryptococcus tsukubaensis, Trichosporon oryzae, Spo robolomyces antarcticus, Candida fusiformata, Sterigmatomyces aphidis, Pseudozyma prolifica, Stephanoascus flocculosus and S. rugulosus form a monophyletic group with Ustilago maydis. All these species, and pro bably T. pallescens as well, belong to the Ustilaginomycetes. However, phylogenetic relationships of Microbotryum violaceum, Itersonilia per plexans and Tilletiopsis pallescens are unresolved by the present data . The position of M. violaceum and I. perplexans is not in conflict wi th their placement in the Urediniomycetes (sensu Swann) and Hymenomyce tes, respectively.