Genetic diversity and differentiation within and between cultivated (Vitis vinifera L. ssp sativa) and wild (Vitis vinifera L. ssp sylvestris) grapes

Genetic characterization of 502 diverse grape accessions including 342 cultivated (V. vinifera ssp. sativa) and 160 wild (V. vinifera ssp. sylvestris) grapes showed considerable genetic diversity among accessions. A total of 117 alleles were detected across eight SSR loci with the average of 14 alleles per locus. The genetic diversity of wild grapes was slightly lower than that observed in the cultivated grapes probably due to small populations and severe natural selection leading to drift and loss of alleles and heterozygosity in wild grapes. The distance cluster analysis (CA) supported the classical ecogeographic groups with moderate genetic differentiation among them. There was a greater affinity of Occidentalis grape to wild grape from the Caucasus than other groups. However, a number of low to moderate frequency alleles that are present in the cultivated grape are not represented in the wild grape.