Ancient Roman grape seeds reveal genetic origins of French winemaking

June 10 (UPI) -- Scientists have traced the genetic origins of a popular grape variety, still used in French wines today, back 900 years to a single ancestral plant.

Deploying methods similar to those used to study human DNA lineages, an international team of scientists analyzed the genetic relationships among both ancient and modern grape varieties. Researchers used DNA collected from grape seeds recovered from several French archaeological sites -- seeds dating to the Iron Age, Roman era and medieval period.

"From our sample of grape seeds we found 18 distinct genetic signatures, including one set of genetically identical seeds from two Roman sites separated by more than 600 kilometers, and dating back 2,000 years ago," Nathan Wales, researcher at the University of York, said in a news release. "These genetic links, which included a 'sister' relationship with varieties grown in the Alpine regions today, demonstrate winemakers' proficiency across history in managing their vineyards with modern techniques, such as asexual reproduction through taking plant cuttings."

One of the ancient grape seeds boasted a genome identical to Savagnin Blanc, a modern grape variety commonly grown in France's Jura region. The discovery, described Monday in the journal Nature Plants, suggests the variety has been grown using clippings from the ancestral plant for at least 900 years.

Though not world famous -- and not to be confused with the popular Sauvignon Blanc -- Savagnin Blanc is consumed by many wine drinkers in France and Central Europe, where it is known by the names Vin Jaune and Traminer, respectively.

"We suspect the majority of these archaeological seeds come from domesticated berries that were potentially used for wine making based on their strong genetic links to wine grapevines," said Jazmín Ramos-Madrigal, a postdoctoral researcher from the University of Copenhagen. "Berries from varieties used for wine are small, thick-skinned, full of seeds, and packed with sugar and other compounds such as acids, phenols, and aromas -- great for making wine but not quite as good for eating straight from the vine. These ancient seeds did not have a strong genetic link to modern table grapes."

Through the writings of Pliny the Elder, a Roman-era writer, historian and naturalist, researchers know the Romans had begun developing advanced grape cultivation and winemaking techniques. But until now, scientists have been unable to link Roman grape names with modern varieties.

"Now we have the opportunity to use genetics to know exactly what the Romans were growing in their vineyards," said Ramos-Madrigal.

Scientists failed to find a direct genetic link to modern varieties among the ancient grape seeds, but they identified close relatives to the grape families responsible for Syrah and Pinot Noir.

Researchers suggest the latest findings could be used to identify unappreciated value among wine lineages with deep historical roots.

"For the wine industry today, these results could shed new light on the value of some grape varieties," Wales said. "Even if we don't see them in popular use in wines today, they were once highly valued by past wine lovers and so are perhaps worth a closer look."