Fig. 1.

Clonal relationships within the USDA grape germplasm collection. (A) Number of clonal relationships was evaluated for each of the 950 vinifera accessions. Most of the accessions [551 (58%) of 950 accessions] have a clonal relationship with at least 1 other accession. (B) Degree of clonal relatedness among all 950 vinifera accessions is represented as a set of clusters. The 399 accessions that do not have a clonal relationship with another accession are shown as lone black dots. Accessions with six or fewer clonal relationships are grouped together with their clones and shown in gray. Clusters of clones with ≥7 accessions are colored, and their names are indicated in the legend. Names listed in the legend are the prime names from the Vitis International Variety Catalogue (http://www.vivc.de/).