A genetics study finds that people first cultivated grapes for wine about 8,000 years ago. In the current Proceedings of the National Academy of Sciences, a team led by Sean Myles of Cornell, looked at "1,000 samples of the domesticated grape, Vitis vinifera subsp. vinifera, and its wild relative, V. vinifera subsp. sylvestris." Comparing the gene maps across the grapes, the team concludes that humanity has only begun to explore the genetic diversity of the humble grape.
     The new study claims 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 years ago. It looks that 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. Grape growing and winemaking then expanded westward toward Europe, but the degree to which local wild sylvestris from Western Europe contributed genetically to Western European vinifera cultivars remains a contentious issue. The results of the study all support a model in which modern Western European cultivars experienced introgression from local wild sylvestris.
     The new analysis suggests that people have been conservative in crossing varieties, after the earliest domestication of wild grapes. The researchers call for genetically-guided cross-fertilization of grape varieties for increased hardiness. "The grape is clearly exceptional in terms of its domestication and breeding history compared with most crops studied to date," the researchers wrote. "The vinifera grape has retained high levels of genetic diversity since its domestication, yet its genetic variation remains relatively unshuffled within an extended pedigree, " they concluded.
   
Edited from USA Today (19 January 2011)