The vine Muscadinia rotundifolia, also known by its vernacular names Scuppernong or southern muscadine, is a grapevine species native to North America. Its Latin name, Vitis rotundifolia, was specified by Michaux, although it was initially named V. vulpina by Linnaeus. J.-E. Planchon retained Michaux's name to avoid any confusion with other species. This vine is distinguished by its morphological characteristics, notably its quadrangular or pentagonal leaves, often unlobed (entire), with a flat and smooth blade, as well as discontinuous and slender tendrils. Significantly, it belongs to the subgenus Muscadinia, which differs from the subgenus Vitis in its chromosome count (2n=40) and various anatomical, morphological, and biological peculiarities.

Muscadinia rotundifolia at the Heart of Alain Bouquet's Work

Muscadinia rotundifolia played an essential role as the starting point for the research of Alain Bouquet, a leading researcher in breeding resistant varieties. Indeed, his varietal selection strategy, distinctive in the world of disease-resistant grape varieties, relied on a hybrid named NC6-15. This was the result of a cross made in the early 20th century by Harold Paul Olmo between the American vine Muscadinia rotundifolia and the European vine Vitis vinifera. The fundamental contribution of NC6-15 lies in the transmission of very high resistance to fungal diseases, inherited from Muscadinia rotundifolia.

A Strategic Choice for Disease Resistance

The choice of Muscadinia rotundifolia as a starting point for creating resistant grape varieties was no coincidence. This species carries very high natural resistance to fungal diseases, such as downy mildew and powdery mildew. This characteristic makes it a major source of resistance genes, essential in current breeding programmes aimed at reducing the use of plant protection products. The objective was to integrate this natural resistance into Vitis vinifera varieties while preserving the organoleptic qualities of the wines. Through successive backcrosses with Vitis vinifera varieties over several generations, the varieties obtained by Alain Bouquet incorporate more than 99% of the V. vinifera genome, while still benefiting from the disease immunity of their American ancestor. This work gave rise to innovations such as the Nemadex Alain Bouquet rootstock, Bouquet 3160-27-4 N (Fer Servadou progeny), and Bouquet 3179-90-7 N (Grenache progeny), demonstrating the importance of this species. Today, more and more winegrowers are taking an interest in resistant grape varieties in Bordeaux and grape varieties tolerant to downy and powdery mildew for more sustainable viticulture. To understand the nuances of these innovations, please consult our glossary of resistant, tolerant, hybrid, and PIWI grape varieties.

Château Cazebonne, an estate committed to preserving and reviving Bordeaux's viticultural heritage, is actively replanting heritage and resistant grape varieties to build the viticulture of tomorrow. This work is made possible thanks to the support of wine lovers who have embraced our wines and are passionate about our approach. To learn more about the fascinating history of Bordeaux vineyards, discover our downloadable book "Bordeaux, A History of Grape Varieties". Test your knowledge and explore the world of wine with our wine quizzes, or discover our wines online to taste the fruit of our commitment.