THE CHROMOSOMAL CONSTITUTION OF WINE STRAINS OF SACCHAROMYCES-CEREVISIAE

A general procedure is described for determining the chromosomal constitution of industrial strains of Saccharomyces cerevisiae based on analysis of segregation frequencies for input markers among random spore progeny of industrial‐laboratory strain hybrids. The multiple auxotrophic haploid testers used carried a dominant erythromycin‐resistance marker, allowing hybrids to be selected in mass matings with produced by the wild‐type industrial strains. Analysis a number of independent crosses between the haploid testers and an unselected population of spores of each wine strain distinguished between disomic, trisomic and tetrasomic chromosomal complements in the parents. Possible explanations for a significant class of aberrant segregation frequencies are discussed. Results of the analysis indicate that UCD Enology 522 (Montrachet) is diployed and possibly trisomic for chromosome VII; 522X is diploid; UCD Enology 505 (California Champagne) is disomic for chromosome XVI, trisomic for chromosomes I, II, III, VI, VIII, IX, X, XII, XV, tetrasomic for chromosomes IV, XI, XIII, XIV and either trisomic or tetrasomic for chromosomes V and VII; and that UCD Enology 595 (Pasteur Champagne) is disomic for chromosomes I, II, III, IX, XVI, trisomic for chromosomes IV, VI, X, XII, XIV, XV, tetrasomic for chromosomes V, VIII, XI, XIII, and either disomic or tetrasomic for chromosome VII. Copyright © 1990 John Wiley & Sons Ltd.