Molecular survey of georgian traditional grapevine genetic resources

The South Caucasus area is considered one of the main centers of origin and domestication for the cultivated grapevine, Vitis vinifera L. ssp. sativa DC. The aim of this work is to study the genetic structure of the Georgian grapevine platform by analyzing 135 Georgian grapevine accessions using 20 SSR molecular markers and to verify the contribution of Georgian germplasm to European viticulture. Among the 135 selected samples, 112 were representatives of traditional Georgian wine and table grape cultivars and 23 were collected from several Georgian woodlands and, after visual inspection, were considered representatives of Vitis vinifera ssp. sylvestris subspecies. Molecular fingerprints (20 SSR loci) of all 135 accessions were compared with data from the 2,300 accessions conserved at the Institut National de la Recherche Agronomique (INRA) grape germplasm repository of Domaine de Vassal. Nei’s genetic distance was calculated among the Vassal and Georgian samples to verify the presence of synonyms and to have an overview of the structure of Georgian grapevine germplasm platform compared with the ones belonging to other countries. Results highlighted that most of Georgian viticulture is quite isolated from elsewhere. The results suggest that the Georgian viticulture is still strongly correlated to its geographic origin, allowing to clearly distinguish groups of accessions belonging to different regions of the country. Among wild samples, the molecular fingerprint has revealed very few mistakes or inter-specific crossings in the pool of collected samples and highlighted that, as already verified for other regions, there is diversification between the wild and cultivated forms. Yet this separation does not seem to be, in the case of Georgia, as robust as seen in other grape growing regions. These results seem to confirm that typical Georgian cultivars weren’t spread to other European countries and, on the other hand Georgian viticulture did not have contaminations from elsewhere. The apparent isolation of Georgian germplasm makes this viticulture particularly interesting for further investigation.