Notes, outline and divergence times of Basidiomycota

The Basidiomycota constitutes a major phylum of the kingdom Fungi and is second in species numbers to the Ascomycota. The present work provides an overview of all validly published, currently used basidiomycete genera to date in a single document. An outline of all genera of Basidiomycota is provided, which includes 1928 currently used genera names, with 1263 synonyms, which are distributed in 241 families, 68 orders, 18 classes and four subphyla. We provide brief notes for each accepted genus including information on classification, number of accepted species, type species, life mode, habitat, distribution, and sequence information. Furthermore, three phylogenetic analyses with combined LSU, SSU, 5.8s, rpb1, rpb2, and ef1 datasets for the subphyla Agaricomycotina, Pucciniomycotina and Ustilaginomycotina are conducted, respectively. Divergence time estimates are provided to the family level with 632 species from 62 orders, 168 families and 605 genera. Our study indicates that the divergence times of the subphyla in Basidiomycota are 406–430 Mya, classes are 211–383 Mya, and orders are 99–323 Mya, which are largely consistent with previous studies. In this study, all phylogenetically supported families were dated, with the families of Agaricomycotina diverging from 27–178 Mya, Pucciniomycotina from 85–222 Mya, and Ustilaginomycotina from 79–177 Mya. Divergence times as additional criterion in ranking provide additional evidence to resolve taxonomic problems in the Basidiomycota taxonomic system, and also provide a better understanding of their phylogeny and evolution.

Cryptotrichosporon siamense sp. nov., a ballistoconidium-forming yeast species in Trichosporonales isolated in Thailand

Two strains, which formed pink colonies and produced ballistoconidia and represented a novel anamorphic yeast species, were isolated from peat (DMKU-SPS1-2) and fern leaf (ST-145) collected in Thailand. Analysis of the sequences of the D1/D2 domains of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) regions showed that the two strains were identical to the sequences of the D1/D2 domains of the LSU rRNA gene and differed by two nucleotide substitutions in the ITS regions. Phylogenetic analysis based on the combined sequences of the ITS and the D1/D2 regions confirmed that the two strains represented a single species in the genus Cryptotrichosporon that was distinct from the other known species of the genus. Cryptotrichosporon argae (CBS 14376^T) was the most closely related species, but with 2.2 % nucleotide substitutions in the D1/D2 domains of the LSU rRNA gene, and 6.8-8.0 % nucleotide substitutions in the ITS regions. Therefore, the two strains were assigned as a novel species, for which we propose the name Cryptotrichosporon siamense sp. nov. The type is DMKU-SPS1-2^T. The MycoBank number of the novel species is MB82336.