Wednesday, July 5, 2023

Grapevine diversification in Europe after the Western Asia domestication event

At this point, we know that there were two simultaneous domestications of vitis sylvestris approximately 11,000 years ago. We also know, based on the Dong, et al., study, that the Caucasian domesticate was not the mother of all European grapevines, being, instead, "a local effort confined to both sides of the Caucasian Mountains." We also know that the Syl-W ecotype of vitis sylvestris occupied ecological niches in Europe proper. 

Give the foregoing,  Dong, et al., needed to explore: (i) the diversification history of European wine grapevines and (ii) "when and how distinct grapevine ancestors formed in Europe with relevance to Syl-W introgressions." In this post I highlight the methodologies utilized to answer those questions and present the results.

The chart below illustrates the methodologies employed and selected results obtained.


The first observation coming out of the TreeMix analysis is evidence of a Syl-W introgression earlier than the occurrence of the Muscat split. The fingerprint of this introgression is present in all further splits. The study team screened the introgression tracts in CG3 to CG6 and found that 10 shared regions among these groups "contain genes that are involved in plant immunity, abiotic stress response and carbohydrate metabolism." This supports the position, according to the authors, that "introgression helps grapevines adapt to new environments and become more suitable for winemaking."

The Muscat split occurred within 500 years of the domestication event, suggesting that it took place within the confines of Western Asia. This split supported grapes for both consumption and winemaking. The modern-day characteristics of selected elements of the Muscat family are illustrated in the chart below.


Post the Muscat split, "... unique ancestries emerged in the Balkans, Iberia, and Western Europe with the help of V. sylvestris introgressions into CG1."

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How did the cultivars identified above make their way to Europe? I will answer that question in the next installment in this series.

©Wine -- Mise en abyme

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