HYBRIDIZATION OF NON‐SPORULATING AND WEAKLY SPORULATING STRAINS OF BREWER'S AND DISTILLER'S YEASTS

Abstract

A method for hybridization of strains of industrial yeasts with auxotrophically marked haploid and diploid strains was developed, using the RD‐auxotrophic technique of Gunge & Nakatomi. Brewing and distilling strains were hybridized with aα or αα diploids and sporulating, near‐tetraploid strains were obtained which could be further subjected to genetic analysis and hybridized by conventional methods. Hybrids could also be obtained between the industrial strains and auxotrophically marked haploid strains, but the viability of the spores obtained from these hybrids was low, and they were probably near‐triploids. This method makes possible the genetic analysis of brewing yeast strains and others which do not sporulate, and allows the mapping of characters which are important in industrial practice, so that new yeast strains having extended ranges of desirable characteristics can be obtained by standard genetic techniques. 1977 The Institute of Brewing & Distilling