Microsatellite analyses for evaluation of genetic diversity among Sicilian grapevine cultivars

A total of 82 grapevine genotypes were sampled from several areas of the Italian region of Sicily where vineyards are widely spread. The grapevines were characterized using six microsatellite markers (VVS2, VVMD5, VVMD7, VVMD27, VrZAG62 and VrZAG79) to evaluate genetic diversity. Thirty-seven of the 82 cultivars sampled had their names quoted in historical and literary sources, while 45 cultivars from old vineyards did not have their names reported in ancient literature. According to their genetic profiles at SSR loci, 70 different cultivars were found, while interesting cases of synonymies (Regina and Moscato bianco, Alicante and Dolcetta or among different clones of Zibibbo and Catarratto) and cases of homonymy (Frappato and Nerello Mascalese) were discovered. Several genetic parameters were calculated to assess the efficacy of the loci chosen in this work. Pairwise genetic distances between all cultivars were calculated. A dendrogram representing the genetic similarities among cultivars was depicted using the UPGMA method to investigate their relationships, explaining them from a historical point of view. The cluster distribution of cultivars clearly does not reflect their current geographical distribution, suggesting successive introductions of cultivars in Sicily from different areas of origin.