Comparison of Two PCR-Based Genetic Fingerprinting Methods for Assessment of Genetic Diversity in Saccharomyces Strains

Two molecular methods, interdelta polymorphism fingerprinting of genomic DNA and COX1 intron polymorphism fingerprinting of mitochondrial DNA, were used to characterize 52 strains of Saccharomyces identified to species by 26S rDNA sequencing only in order to assess the potential of these techniques for strain typing and genetic analysis individually and in combination. Two laboratory isolates derived from the same parentage served as a control. Forty-seven S. cerevisiae strains representing a mix of commercial strains and vineyard or winery isolates were used. Five of these strains have been given the commercial designation S. cerevisiae race bayanus. Three strains were identified as S. bayanus, S. kudriavzevii, and S. servazzii from their 26S rDNA sequence and thus may be hybrids. Forty-four genetic patterns were found among the strains by interdelta polymorphism fingerprinting and 47 genetic patterns were found by COX1 intron polymorphism fingerprinting. Each method allowed differentiation of the majority of strains but grouped strains into different clusters. Strains were clustered into eight groups using both techniques in combination. The two laboratory strains clustered together but were in a larger grouping of wine strains. Saccharomyces bayanus, S. kudriavzevii, and S. servazzii were separated from each other but each clustered with S. cerevisiae strains and could not be differentiated from S. cerevisiae by either method. Three of the S. cerevisiae race bayanus strains clustered together but the other two were in different groupings. Of the 10 commercial strains, 904 (French Red) was grouped alone, while 522 (Montrachet) and 905 (Premier Cuvee) were grouped with wild isolates from different areas. Thus both methods reveal patterns of strain similarity but neither method differentiated strains by species or by origin.