Bensingtonia rectispora sp. nov. and Bensingtonia bomiensis sp. nov., ballistoconidium-forming yeast species from Tibetan plant leaves Qi-Ming Wang, 1 Teun Boekhout 2 and Feng-Yan Bai 1 Correspondence Feng-Yan Bai baify@im.ac.cn 1 State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, PR China 2 CBS Fungal Diversity Centre, Royal Netherlands Academy of Arts and Sciences, 3584 CT Utrecht, The Netherlands Five yeast strains isolated from plant leaves collected in south-east Tibet formed cream to brownish colonies and produced asymmetrical ballistoconidia and CoQ-9 as the major ubiquinone. Sequence analysis of the 26S rRNA D1/D2 domain and the internal transcribed spacer region indicated that these strains represented two novel species of the genus Bensingtonia. The names Bensingtonia rectispora sp. nov. (type strain XZ 4C5 T 5CGMCC 2.02635 T 5CBS 10710 T ) and Bensingtonia bomiensis sp. nov. (type strain XZ 33D1 T 5CGMCC 2.02670 T 5CBS 10713 T ) are proposed for the two novel species, which are phylogenetically closely related to Bensingtonia naganoensis, Bensingtonia pseudonaganoensis and the type species of the genus, Bensingtonia ciliata. The genus Bensingtonia was described by Ingold (1986) and emended by Nakase & Boekhout (1988) to accommodate basidiomycetous yeasts characterized by the production of ballistoconidia, the formation of CoQ-9 as the major ubiquinone and the absence of xylose in the cell wall (Nakase et al., 2011). The genus is highly polyphyletic though only 15 species are currently recognized (Takashima et al., 1995; Fell et al., 2000; Hamamoto & Nakase, 2000; Scorzetti et al., 2002; Wang et al., 2003, 2006; Nakase et al., 2011). Thirteen Bensingtonia species, including the type species Bensingtonia ciliata, belong to the Agaricostilbales in the Agaricostilbomycetes, whereas the other two species, Bensingtonia yamatoana and Bensingtonia intermedia (Mas- tigobasidium intermedium), are located in separate lineages of the Microbotryomycetes (Boekhout et al., 2011; Nakase et al., 2011). The Bensingtonia species in the Agaricostilbales occur in at least four different lineages or clades inter- mingled with species of Agaricostilbum, Kondoa and Sterig- matomyces (Fell et al., 2000; Scorzetti et al., 2002; Wang et al., 2003, 2006; Boekhout et al., 2011; Nakase et al., 2011). Only two species, Bensingtonia naganoensis and Ben- singtonia pseudonaganoensis, cluster together with the type species (B. ciliata) in a strongly supported clade (Wang et al., 2006; Nakase et al., 2011). Reclassification of Bensingtonia and related genera will be necessary in the future and the addition of novel species to the B. ciliata clade will be valuable for both phenotypic and phylogenetic redefinition of the genus. In recent years, we have been investigating phyllosphere yeast diversity. Of the ballistoconidium-forming yeast strains isolated from Tibet, five strains that formed bilaterally symmetrical ballistoconidia and possessed CoQ-9 as the major ubiquinone were isolated; studies revealed that these strains represent two novel Bensingtonia species closely related to the type species B. ciliata. Strains XZ 4C5 T , XZ 5C1-D, XZ 9C3-D, XZ 14B3-2 and XZ 33D1 T (Table 1) were all isolated from wilting plant leaves collected from mixed coniferous and broad leaved forests in Nyingchi (coordinates: 30 u 179 N 94 u 409 E) and Bomi (coordinates: 30 u 489 N 95 u 449 E) counties, south-east Tibet, China, in July 2004, by using the improved ballistoconidia- fall method as described by Nakase & Takashima (1993). The two counties are adjacent, are approximately 3000 m above sea-level and have similar climates, with mean annual temperatures of 8–9 u C and annual precipitation of 600– 900 mm. Most of the morphological, physiological and biochemical characteristics were examined according to standard methods (Kurtzman et al., 2011). Assimilation of nitrogen compounds was investigated on solid media with starved inocula (Nakase & Suzuki, 1986). Extraction, purification and identification of ubiquinones were carried out according to Yamada & Kondo (1973). Nuclear DNA was extracted by using the method of Makimura et al. (1994). The internal transcribed spacer Abbreviation: ITS, internal transcribed spacer. The GenBank/EMBL/DDBJ accession numbers for the ITS region and 26S rRNA gene D1/D2 domain sequences of strains XZ 4C5 T , XZ 5C1-D, XZ 9C3-D, XZ 14B3-2 and XZ 33D1 T are JN620351– JN620355, respectively. International Journal of Systematic and Evolutionary Microbiology (2012), 62, 2039–2044 DOI 10.1099/ijs.0.038117-0 038117 G 2012 IUMS Printed in Great Britain 2039