DNA analysis has solved another question of parentage, this time of a wine. The popular dry, red cabernet sauvignon comes from a grape that is a cross of two other varieties of Vitis vinifera, cabernet franc and sauvignon blanc, according to viticulture researchers from the University of California, Davis.
Despite the similarity of the grapes' names, write John E. Bowers and Carole P. Meredith in the May Nature Genetics, cabernet sauvignon's genetic link to the sauvignon blanc grape, the source of a light white wine, is a surprise. Yet the researchers' analysis of 30 different genetic markers from the DNA of 51 different grape cultivars--ranging from alicante bouschet to zinfandel--rules out any other possible ancestors except the blanc and the red cabernet franc, which has long been considered a close relation.
The two vines probably grew near each other in the Bordeaux region of France in the 17th century, and a chance cross-pollination led to the new character, the researchers speculate. Cabernet sauvignon is now the world's second most widely planted grape vine for wine.