DNA Fingerprint Characterization of Some Wine Grape Cultivars

Abstract

In order to develop an objective and reliable method of grape identification, a DNA fingerprinting strategy similar in concept to that used to identify human beings was applied to a diverse group of cultivars, including the most important California wine grapes. DNA was extracted from young leaves and shoot tips of 43 accessions, digested with <i>Hind</i> III or <i>Eco</i> RV and probed with five low-copy number DNA clones selected from a grape genomic DNA library. Restriction length polymorphism analysis revealed unique patterns for all accessions presumed to be distinct cultivars. The probability that two different cultivars would share the same pattern was calculated to be 5.64 x 10^-8. Identical banding patterns were produced by Zinfandel and Primitivo, supporting the hypothesis that these are synonyms for a single cultivar. Similarly, the pattern of the accession now designated as Pinot noir 19 (previously known as Gamay Beaujolais in California) was identical to that of Pinot noir 1, supporting ampelographic opinion that the former is in fact a form of Pinot noir and not a distinct cultivar. Pinot gris, widely held to be a berry color mutant of Pinot noir, also had the Pinot noir pattern. By contrast, identical patterns were not observed for single accessions of Petite Sirah and of Durif, thought by some to be synonymous. While the method described here does not detect intra-cultivar variation (clones and bud sports), the results obtained in this survey strongly suggest that this approach will be able to uniquely characterize additional grape cultivars and will serve as a valuable adjunct to ampelography.