900-year-old grape seeds reveal the uninterrupted history of the French wine variety | Science


Today's drinkers may have more to do with medieval alcohols than a simple hangover: research suggests they might drink a wine made from identical grapes.

Vines are often grown from existing plant cuttings or by techniques such as grafting, rather than sowing, because they offer much greater consistency in grapes.

This has led some to believe that some varieties could remain virtually unchanged for two millennia since the boom in Mediterranean wine production in the Mediterranean. The grapes were first domesticated more than 6,000 years ago in southwestern Asia.

The latest research suggests that this may not be exaggerated. Scientists say they have discovered that vineyards producing white Savagnin grapes are now genetically identical to vines grown in Orléans 900 years ago.

"It says a lot about the ingenuity of the winemakers. They have been using similar techniques for centuries and keep alive certain vines that consumers value a lot, "said Dr. Nathan Wales, co-author of the research. York University.

Wales and his colleagues report writing in the journal Nature Plants that they had analyzed recovered DNA from 28 grape seeds found at nine archaeological sites in France, focusing on the genetic material contained in the seeds and seeds. from the vine on which the grapes had grown. Specifically, the team examined 10,000 specific DNA points and compared what she saw with such data for hundreds of domesticated and wild modern varieties.

The dating of objects or organic materials near the seeds revealed that some of the ancient glitches dated back to the iron age, about 500 BC, while others came from different eras of the Roman and other times of the medieval era – the latest glitches dating back to the time. early 13th century.

Analysis of the team's DNA revealed that the 28 seeds came from domestic vines rather than wild varieties, most of them linked to modern Western European varieties used for winemaking.

Wales said that several pieces of evidence suggest that they had actually been involved in the production of a glass.

"Many of these sites are related to winemaking or apparent vineyards," Wales said, adding that the sites where the seeds were found also provided a clue. "Once you've pressed the grapes to make the juice, you have to drop [the seeds]. Archaeological sites are often frequented by latrines or by wells that are no longer used. "

Subsequent work has shown that different varieties are sometimes grown on one site, whereas in some cases two or more identical genetically identical seeds were found in the same soil layer on one site, suggesting that the grapes could have grown on the same site. vine. Curiously, a pair of seeds dating from the 2nd century AD AD and found 600 km away in Alsace and Mediterranean France, also grew on genetically identical plants. "These genetic clones suggest that the Romans transported the vine for long distances … most likely in the form of cuttings," write the authors.

"It was really cool for us because they have the same genetic sequence, but they are separated by hundreds of kilometers," Wales said. "The only way to explain it, is that genetically, the same vines grow far away from each other."

One seed revealed that the vines producing grapes in Orléans between 1050 and 1200 AD were genetically identical to those producing the white Savagnin grapes today. In other words, it seems that the vines have been cut continuously for about 900 years.

"Basically, it's an identical twin that has just been maintained forever," Wales said. In addition, the seeds of Roman origin of a site of Tourbes have a parent-child relationship with grapes for the white savagnin. This, the authors write, might suggest that "either the Savagnin Blanc or his direct relatives, have been cultivated in France since the first century. [AD]. "

But if the old wine would have had the same taste as today's is another matter; As Wales points out, factors such as terroir and processing techniques also affect flavor.


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