Diversity and phylogeny of basidiomycetous yeasts from plant leaves and soil: Proposal of two new orders, three new families, eight new genera and one hundred and seven new species

Funding Information: We thank Prof. Jian-Yun Zhuang for his advice on nomenclatural matters. We thank Dr. Alexander Idnurm for his kindly providing the sequences and informations of strain IAM13481 and his critical comments for this manuscript, Dr. Aleksey Kachalkin for his sharing the physilogical data of strain KBP Y-5548 and Masako Takashima for her sharing the physilogical data of strain TY-217. We also thank Ana Pontes and Cl?udia Carvalho for editing illustrations of Kondoa myxariophila and for ITS sequencing, respectively. This study was supported by grants No. 31570016 from the National Natural Science Foundation of China (NSFC) and national project on scientific groundwork No. 2014FY210400 from the Ministry of Science and Technology of China. The authors are solely responsible for the content of this work. Nearly 500 basidiomycetous yeast species were accepted in the latest edition of The Yeasts: A Taxonomic Study published in 2011. However, this number presents only the tip of the iceberg of yeast species diversity in nature. Possibly more than 99 % of yeast species, as is true for many groups of fungi, are yet unknown and await discovery. Over the past two decades nearly 200 unidentified isolates were obtained during a series of environmental surveys of yeasts in phyllosphere and soils, mainly from China. Among these isolates, 107 new species were identified based on the phylogenetic analyses of nuclear ribosomal DNA (rDNA) [D1/D2 domains of the large subunit (LSU), the small subunit (SSU), and the internal transcribed spacer region including the 5.8S rDNA (ITS)] and protein-coding genes [both subunits of DNA polymerase II (RPB1 and RPB2), the translation elongation factor 1-α (TEF1) and the mitochondrial gene cytochrome b (CYTB)], and physiological comparisons. Forty-six of these belong to 16 genera in the Tremellomycetes (Agaricomycotina). The other 61 are distributed in 26 genera in the Pucciniomycotina. Here we circumscribe eight new genera, three new families and two new orders based on the multi-locus phylogenetic analyses combined with the clustering optimisation analysis and the predicted similarity thresholds for yeasts and filamentous fungal delimitation at genus and higher ranks. Additionally, as a result of these analyses, three new combinations are proposed and 66 taxa are validated. publishersversion published