Proposal of one new family, seven new genera and seventy new basidiomycetous yeast species mostly isolated from Tibet and Yunnan provinces, China

Abstract

More than 2 000 yeast strains isolated from 1 200 samples mostly collected from Tibet and Yunnan provinces in China were identified as 462 species according to the internal transcribed spacer including the 5.8S rDNA (ITS) and the D1/D2 domains of the large subunit rDNA (LSU) sequence analyses. Among them, 70 new basidiomycetous yeast species were proposed based on the multi-locus phylogenetic analyses including the D1/D2 domains, the ITS, the small subunit rDNA (SSU), the largest subunit of RNA polymerase II (RPB1), the second largest subunit of RNA polymerase II (RPB2) and translation elongation factor 1-α (TEF1), as well as the phenotypic comparisons. The average nucleotide identity (ANI) analysis with the genomic metric was also used in the evaluation of the species delimitation for the genera Holtermannia, Mrakia and Takashimella that contain closely related species with low sequence heterogeneity in both ITS and D1/D2 regions. Forty-six new species belonged to 16 genera in the Agaricomycotina, 13 new species occurred in 12 genera in the Pucciniomycotina, three new species were distributed in three genera in the Ustilaginomycotina, and eight new species were classified in seven newly established genera. One new family was also proposed based on one of these new genera. The analyses revealed several inaccurate species names attributed to genomes deposited in GenBank, indicating the necessity of a more rigorous quality checks of the genomes deposited in the public databases.