DNA extracted from 2,000-year-old grape seeds found in ancient wells in Tuscany has enabled scientists to map the most extensive genetic history of grapevines recovered from a single site.

The findings revealed that vineyards of the Roman era formed part of the empire’s sophisticated agricultural network that might have influenced the development of modern winemaking.

The research led by scientists at the University of York also found that white grapes once dominated the site in Chianti, an area of Tuscany famous for its red sangiovese wines.

The discovery was made at Cetamura del Chianti, a hilltop archaeological site that was home to the Etruscans before the arrival of the Romans and then medieval Italians. Those living there between 300BC and 300AD dropped grape pips into deep wells, where they were preserved in oxygen-free mud.

“We sequenced the DNA of 80 seeds and found a remarkable story of continuity,” said Dr Oya Inanli, the study’s co-author from the University of York. “A large majority of the tested seeds belonged to a single, identical variety passed directly from the Etruscans to the Romans and maintained for centuries.

“We were also able to go a step further with the genetic testing and determine the colour of the ancient grapes. The markers revealed that this dominant, long-lived clone produced white berries.”

The prevalence of white grapes was a surprise for the researchers.

Nancy De Grummond, a professor at Florida State University, which has been undertaking excavations at Cetamura del Chianti since 1973, said: “Our team’s research adds an important chapter on the history of wine in the viticulture region of Chianti.

“What a delightful surprise to learn that the world-famous red wine of today was actually preceded by a white vintage that was curated and maintained for centuries in Etruscan and Roman times.”

After the Roman conquest of the settlement, new grape varieties appeared at Cetamura, possibly pointing to vines introduced from elsewhere across the empire, the study showed. Genetic testing also revealed that the dominant cetamura clone was closely related to two ancient grape seeds previously tested from southern France.

The researchers said this provided biological evidence of long-distance agricultural networks across the Roman empire that might have contributed to the standardised production of wine today.