European wine grapes (Vitis vinifera) originated from the hybridization of western Asian-domesticated table grapes and local wild relatives, according to new research led by University of Udine scientists.
“Phylogeography of cultivated grapes is linked to the history of ancient populations that settled across the Caspian Sea Basin, the Near East and the Mediterranean Basin,” senior author Professor Michele Morgante from the Department of Agricultural, Food, Environmental and Animal Sciences at the University of Udine and the Istituto di Genomica Applicata and his colleagues wrote in their paper.
“Grape cultivation and winemaking began somewhere in the South Caucasus, the northern Fertile Crescent, or the Levant, following domestication from local forms of the wild ancestor that has a broad geographic distribution.”
“From the cradle of domestication, grape cultivars followed a predominant westward pattern of dispersal, driven by human migration and maritime trades, paralleled by a differentiation in use for fresh consumption (table grapes) or winemaking (wine grapes).”
“The cultivation of domesticated grapes dates back 4,000 years in the eastern Mediterranean and 2,000 years in Western Europe, with vegetative propagation becoming more and more prevalent as a mode of reproduction to preserve the genetic identity of valuable accessions that may have arisen from spontaneous crosses.”
“Paleogenomic evidence supports a very early adoption of vegetative propagation and an ancient origin of some of the currently cultivated varieties, with Savagnin Blanc being at least 900 years old.”
“Western European varieties are the foundation of the global wine industry, with ten varieties (Cabernet Sauvignon, Merlot, Tempranillo, Airen, Chardonnay, Syrah, Grenache, Sauvignon Blanc, Pinot Noir, Trebbiano Toscano) accounting for 26% of the vineyards worldwide.”
In order to elucidate the still controversial processes that originated European wine grapes from its wild progenitor, the researchers analyzed the genomes of 204 Vitis vinifera.
They suggest that the grapes originated from a single domestication event in western Asia, most likely in the South Caucasus, followed by multiple rounds of inter-breeding with the European wild grape population.
They also identified the genetic footprints for domestication and breeding selection, which determine the grapes used for today’s wine making.
The authors observed similar levels of genetic diversity in wild grapes and in the varieties used for today’s wine making.
Additionally, the findings suggest that Italy and France have the most genetic diversity among their cultivated grapevines of the European countries included in samples.
“We show that all analyses support a single domestication event that occurred in Western Asia and was followed by numerous and pervasive introgressions from European wild populations,” the scientists wrote in the paper.
“This admixture generated the so-called international wine grapes that have diffused from Alpine countries worldwide.”
“Across Europe, marked differences in genomic diversity are observed in local varieties that are traditionally cultivated in different wine producing countries, with Italy and France showing the largest diversity.”
“Three genomic regions of reduced genetic diversity are observed, presumably as a consequence of artificial selection.”
“In the lowest diversity region, two candidate genes that gained berry-specific expression in domesticated varieties may contribute to the change in berry size and morphology that makes the fruit attractive for human consumption and adapted …….