PHYLOGENETIC STUDY OF THE ANAMORPHIC BASIDIOMYCETOUS YEASTS RHODOTORULA LACTOSA AND R. MINUTA, AND RELATED TAXA BASED ON 18S RIBOSOMAL DNA SEQUENCES

摘要

The 18S ribosomal DNA (rDNA) sequences were determined for two anamorphic basidiomycetous yeasts, Rhodotorula lactosa and R. minuta. A phylogenetic tree was constructed by the neighbor-joining method using ascomycetous yeasts as an outgroup. The p-aminobenzoic acid (PABA) requiring species, R. lactosa, R. minuta, Erythrobasidium hasegawianum, and Rhodosporidium dacryoidum formed an independent lineage with 100% bootstrap confidence level in the basidiomycetous yeasts lacking xylose. In contrast, R. glutinis, the type species of Rhodotorula, showed a close relationship to Rhodosporidium toruloides and other non-PABA requiring basidiomycetous yeasts that lack xylose in the cell. The molecular phylogeny from this study showed the heterogeneity of the genus Rhodotorula, and suggested the taxonomic importance of PABA requirement in Rhodotorula and related taxa.