|Dangl, Gerald - UNIV. CALIFORNIA, DAVIS|
|Mendum, Mary Lou - UNIV. CALIFORNIA, DAVIS|
|Walker, M - UNIV. CALIFORNIA, DAVIS|
|Meredith, Carole - UNIV. CALIFORNIA, DAVIS|
Submitted to: Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 22, 2001
Publication Date: May 22, 2001
Citation: Genome 44-3:432-438 (2001) Interpretive Summary: The mission of the National Plant Germplasm System is to maintain the genetic diversity of important crop species. For clonally propagated crops such as grape, which must be kept as plants instead of seed, limited resources require that maximum diversity be represented by the minimum number of accessions. For grape this task is particularly difficult. Many ancient grape cultivars have spread around the word under different names, and the origins of other cultivars are obscure. Documentation is frequently poor and misidentifications common, making identification of appropriate accessions problematic. We used a system for creating DNA fingerprints of grape cultivars using simple sequence repeat loci. Analysis of these fingerprints allowed us to identify multiple plantings of the same cultivar and to correct misidentifications. The analysis also provided clues to the origin of cultivar groups, and thus the areas of the grape collection that are over- or underrepresented. This investigation shows the usefulness of DNA fingerprinting as a tool for efficient management of germplasm.
Technical Abstract: Simple sequence repeat markers with high allelic diversity were used to generate "DNA fingerprints" for a set of grapevines from the National Clonal Germplasm Repository, Davis. The vines tested were either seedless table grape cultivars or cultivars with names similar to table grape cultivars. The Proportion of Shared Alleles was selected as the most appropriate statistical measure of genetic distance for this population. Known synonyms were confirmed, and a previously unknown synonym was discovered. An alleged synonym in the literature was disproved by the DNA data. The data was consistent with known parentage, where such data was available. Two mislabeled vines in the USDA collection were identified. UPGMA grouped the cultivars loosely into three groups: a group of nine mostly Middle Eastern cultivars, a group of 22 accessions mostly from Russia and Afghanistan which were morphologically similar to 'Thompson Seedless', and a third very loose group of 11 accessions consisting mostly of eastern European wine grape cultivars. The limitations and usefulness of this type of analysis are discussed.