Molecular phylogenetic study of the basidiomycetous anamorphic yeast genusTrichosporon and related taxa based on small subunit ribosomal DNA sequences

Small subunit ribosomal DNA sequences of all species of the basidiomycetous anamorphic yeast genusTrichosporon were determined, and phylogenetic trees were constructed by the neighbor-joining and maximum likelihood methods. The sequence data showed that, with the exception ofT. pullulans, the genus is monophyletic, although its members have two different major ubiquinones, Q9 and Q10. The genus can be divided phylogenetically into three major clusters. Species with Q10 as the major ubiquinone constitute a single cluster, while those with Q9 form two clusters.Trichosporon pullulans was phylogenetically distinct from other taxa of the genus. It is located in a cluster containingCystofilobasidium capitatum, Mrakía frigida, Xanthophyllomyces dendrorhous and three species ofUdeniomyces. This result sugests thatT. pullulans does not belong to the genusTrichosporon.