Abstract: The genotypic polymorphism and polygenetic affinities of intergenus, interspecies and intraspecies among 21 strains from 6 yeast genus were studied with random amplified polymorphism DNA(RAPD) analysis.The results showed that the mini-differences of intraspecies in genetics could be distinguished and particular electrophoretic bands were selected as characteristic markers in the classification and identification of yeast with RAPD.The genetic distance between Candida shehatae and C.tropicalis was 0.114,and the genetic distance between them and Pichia stipitis reached 0.493.The genetic distance between Schizosaccharomyces pombe and Bettanomyces custersii was 0.322,the genetic distance between Pachysolen tanophilus and C. krusei was 0.383 and the genetic distance between them and Saccharomyces cerevisiae reached 0.443.The genotypic classification of species except Candida seemed to be consis-tent with traditional morphological classification.

Key words: yeast, molecular marker, classification and identification, polygenetic affinities