Grape DNA: Where Do Grape Varieties Come From?

The story behind crossover between grape varieties, and which grapes are used for your favorite wines

The discovery of DNA is one of the most important findings in biology in the last century. Did you know DNA has also been very important in the cultivation of grapes? Just as humans have DNA, plants — including grapes — use DNA for reproduction as well.

Take one of the most widely known red grape varieties in the world, cabernet sauvignon. For years, the origin of this grape was not known, but it was thought to have dated as far back as ancient Rome. However, DNA testing in the 1990s at the University of California at Davis revealed it was the offspring of cabernet franc and sauvignon blanc, and that the crossing probably occurred in 17th-century France.

Most probably by chance, the pollen of one of the parent varieties was blown into the wind and landed on the other parent’s stigma, thereby allowing fertilization to occur. And just as in humans, cabernet sauvignon has genetic characteristics of both its parents. Cabernet sauvignon has the structure and tannin profile of cabernet franc, and the hint of green associated with sauvignon blanc.

Another example of information from DNA testing is the discovery of the origin chardonnay. It was revealed, again by UC Davis, that chardonnay was born in France during the Middle Ages thanks to an accidental crossing of pinot noir with the less than noble white grape gouais blanc.

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