Microsatellite variability in grapevine cultivars from different European regions and evaluation of assignment testing to assess the geographic origin of cultivars

Nine microsatellite markers (VVMD5, VVMD7, VVS2, ssrVrZAG21, ssrVrZAG47, ss rVrZAG62, ssrVrZAG64. ssrVrZAG79 and ssrVrZAG83) were chosen for the analys is of marker information content, the genetic structure of grapevine cultiv ar gene pools, and differ entiation among grapevines sampled from seven Eur opean vine-growing regions (Greece, Croatia, North Italy, Austria and Germa ny, France, Spain and Portugal). The markers were found to be highly inform ative in all cultivar groups and therefore constitute a useful set for the genetic characterization of European grapevines. Similar and high levels of genetic variability were detected in all investigated grapevine gene pools . Genetic differentiation among cultivars from different regions was signif icant, even in the case of adjacent groups such as the Spanish and Portugue se cultivars. No genetic differentiation could be detected between vines wi th blue and white grapes, indicating that they have undergone the processes of cultivar development jointly. The observed genetic differentiation amon g vine-growing regions suggested that cultivars could possibly be assigned to their regions of origin according to their genotypes. This might allow o ne to determine the geographical origin of cultivars with an unknown backgr ound. The assignment procedure proved to work for cultivars from the higher differentiated regions, as for example from Austria and Portugal.