Archaeological evidence suggests that grape domestication took place in the South Caucasus between the Caspian and Black Seas and that cultivated vinifera then spread south to the western side of the Fertile Crescent, the Jordan Valley, and Egypt by 5,000 y ago (1, 21). Our analyses of relatedness between vinifera and sylvestris populations are consistent with archaeological data and support a geographical origin of grape domestication in the Near East (Fig. 4 and Table 1).
The genetic confirmation of the archaeological inference is particularly interesting, since "wine"is part of the Proto-Indo-European lexicon, and has related forms in both Kartvelian (South Caucasian) and Semitic languages. The Transcaucasus seems a quite good place to seek early contact between these three language families. Interestingly, the area between the Black Sea and Caspian is also where genetic analysis of Indo-Aryan origins has brought me.
PNAS doi: 10.1073/pnas.1009363108
Genetic structure and domestication history of the grape
Sean Myles et al.
The grape is one of the earliest domesticated fruit crops and, since antiquity, it has been widely cultivated and prized for its fruit and wine. Here, we characterize genome-wide patterns of genetic variation in over 1,000 samples of the domesticated grape, Vitis vinifera subsp. vinifera, and its wild relative, V. vinifera subsp. sylvestris from the US Department of Agriculture grape germplasm collection. We find support for a Near East origin of vinifera and present evidence of introgression from local sylvestris as the grape moved into Europe. High levels of genetic diversity and rapid linkage disequilibrium (LD) decay have been maintained in vinifera, which is consistent with a weak domestication bottleneck followed by thousands of years of widespread vegetative propagation. The considerable genetic diversity within vinifera, however, is contained within a complex network of close pedigree relationships that has been generated by crosses among elite cultivars. We show that first-degree relationships are rare between wine and table grapes and among grapes from geographically distant regions. Our results suggest that although substantial genetic diversity has been maintained in the grape subsequent to domestication, there has been a limited exploration of this diversity. We propose that the adoption of vegetative propagation was a double-edged sword: Although it provided a benefit by ensuring true breeding cultivars, it also discouraged the generation of unique cultivars through crosses. The grape currently faces severe pathogen pressures, and the long-term sustainability of the grape and wine industries will rely on the exploitation of the grape's tremendous natural genetic diversity.