Microsatellite analysis to define genetic diversity of grapevines (Vitis vinifera L.) grown in Central and Western Mediterranean countries

PCR-based microsatellite analysis has been applied to define the relationships among 238 grapevine cultivars selected as representative of local germplasm in the Central and Western Mediterranean regions. The estimation of genetic distances among the five grapevines groups, based on cluster analysis, c2 tests and Principal Component Analysis, was coherent with a common geographic origin of cultivated grapes and of their primordial varietal radiation. In fact, genetic similarity was high among French and Iberian cultivars and among Greek and Balkan cultivars. The Italian grapes clustered in an intermediate position, reflecting its geographical location. Results show that the geographical distribution is consistent with a pattern of viticulture based on the origin of primordial varieties from regions in the Near East, and subsequent and multiple variety flows that linked different viticultural regions through different routes. This is coherent with the model of varietal diffusion proposed on the bases of archaeological and historical evidence, in which population movements and cultural exchange contributed to the phenomenon.