Genetic Structure, Origins, and Relationships of Grapevine Cultivars from the Castilian Plateau of Spain

Abstract

Four hundred twenty-one cultivated (Vitis vinifera ssp. sativa) and four alleged wild grapevine samples (putative Vitis vinifera ssp. sylvestris) from the Castilian Plateau in northern central Spain were genotyped at the six nuclear microsatellite loci (SSRs) proposed as a standard set for cultivar identification by the GENRES 081 project, yielding 121 different genotypes. The cultivated data set yielded 300 redundant samples, 13 homonyms, and 27 previously unreported genotypes, almost one-fourth of the nonredundant genotypes. Nonredundant genotypes were examined at another 16 nuclear and three chloroplast additional microsatellite loci for further analyses. Three differentiated genetic clusters were detected among them, separating (1) Muscat-type accessions and interspecific Vitis hybrids, (2) accessions from France and the western Castilian Plateau, and (3) accessions from the central Castilian Plateau together with local table grapes. The close relatedness of accessions from the western plateau among each other and to French varieties supported introduction of the latter along the pilgrimage route to Santiago de Compostela. White-berried cultivars from the central plateau were also closely related. Chlorotype data suggested that previously unpublished genotypes and autochthonous Castilian varieties had local origins or resulted from crosses between introduced and local varieties. Morphological features and allelic composition suggested that three of the four samples collected from wild habitats were closely related and might represent genuine Vitis vinifera ssp. sylvestris individuals.