DNA has spoken: Vine cultivation in France dates back more than 4,000 years
Grape seeds found at archaeological sites may seem insignificant. Yet analyzing their DNA provides insight into the history of cultivated grapevines spanning thousands of years.
Rémi Noraz, University of Montpellier
We sequenced the genomes of grape seeds dating back several millennia, revealing a history that archaeology had already begun to uncover: the introduction of viticulture in France, the exchange of grape varieties across Europe, and ancient agricultural practices that have left their mark to this day.
Our findings, published very recently in *Nature Communications*, show in particular that certain iconic grape varieties, such as Pinot Noir—Burgundy’s flagship variety—were already present in the Middle Ages.
How did we analyze the DNA from 4,000-year-old grape seeds?
For a long time, the history of viticulture has relied on the morphological study of grape seeds. This powerful approach has made it possible to identify major trends—particularly regarding whether seeds are wild or domesticated—and to trace the origins of viticulture.
However, certain questions remained difficult to resolve: the geographical origin of grape varieties, their genetic relationships, and the methods of propagation (hybridization or clonal reproduction) and the movement of plants. Ancient DNA, which can be preserved deep within the seeds, provides particularly decisive evidence here, shedding light on the connections between the vines of the past and those of today.
We analyzed 49 seeds from various archaeological sites, mostly in France, spanning nearly 4,000 years, from the Bronze Age to the end of the Middle Ages. These water-saturated seeds were preserved in specific, moist environments, which contributed to the good preservation of their DNA.
The DNA was extracted in the laboratory specializing in ancient DNA at the Toulouse Center for Anthropobiology and Genomics, which was designed to isolate and manipulate the rare and degraded molecules that have survived through the ages in archaeological remains. This ancient DNA was decoded using state-of-the-art sequencing technologies, allowing researchers to read its entire genetic information—in this case, a genetic sequence of approximately 500 million letters.
This data makes it possible to establish genetic relationships between individuals, identify the origins of grape varieties, and trace past propagation techniques: either through crossbreeding, combining varieties of different origins or distinct qualities; or through clonal propagation (via cuttings, layering, or grafting) to preserve, over time, a variety that was particularly valuable to them.
Our discovery proves the long history of viticulture
The first cultivated grapevines appeared in France around 600 BCE, with the growth of trade in the Mediterranean region, particularly in wine. They coexisted with local wild grapevines, and crossbreeding between these two types contributed to the diversity of grape varieties.
Genetic analyses also confirm the existence of long-distance dispersal as early as this period. Influences from Iberia, the Balkans, and the Near East attest to the exchange of plants and know-how throughout the Mediterranean and, more broadly, across Europe.
Another important point: clonal propagation appears to have been an ancient and common practice, already in use as early as the Iron Age. It made it possible to preserve certain varieties of interest over long periods of time and to spread them over long distances.
It is in this context that we identified a medieval grape variety considered to be genetically identical to today’s Pinot Noir, illustrating the continuity of certain grape varieties over several centuries.
What are the prospects for this research?
The value of ancient DNA is not limited to confirming existing scenarios; it also opens up new avenues of research.
By combining historical and modern data, it becomes possible to gain a deeper understanding of the characteristics of vineyards from the past. Recent approaches, for example, make it possible to infer certain characteristics of historical grapes, such as berry color or certain flavor traits.
These methods could also provide a better understanding of how grape varieties adapted to past environments, or of the choices made by ancient societies regarding their agricultural practices.
Ultimately, this research helps to better document the genetic diversity of grapevines and their evolution, which is a key issue in the current context of climate change.
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Rémi Noraz, Ph.D. candidate in Archaeobiology and Paleoecology, University of Montpellier
This article is republished from The Conversation under a Creative Commons license. Readthe original article.