THE PHYLOGENETIC RELATIONSHIPS OF THE Q9-EQUIPPED, SPHEROIDAL ASCOSPORE-FORMING PICHIA SPECIES BASED ON THE PARTIAL SEQUENCES OF 18S AND 26S RIBOSOMAL RNAS

摘要

Seven strains of Pichia abadieae, P. carsonii, P. etchellsii, P. humboldtii, and Candida ingens were examined for partial base sequences in positions 493-622 (130 bases) and positions 1611-1835 (225 bases) of 26S rRNA and in positions 1451-1618 (168 bases) of 18S rRNA. These three partial base sequencings indicated that P. abadieae and P. humboldtii (and C. ingens) are phylogenetically distant from P. carsonii and P. etchellsii. In contrast, the latter two species, P. carsonii and P. etchellsii had very close relationships to Debaryomyces species. Some discussions were made, especially on transferring the two Pichia species to the genus Debaryomyces.