Crop Wild Relatives of Grape (Vitis vinifera L.) Throughout North America

Abstract

Although cultivated grapevines (Vitis vinifera L.) were domesticated from their closest relative in Central Asia, grape wild relatives from North America are vital due to their use as grafted rootstocks. Rootstocks derived from North American Vitis species are critical to the global wine, table, and raisin grape industries for resistance to the root pest phylloxera (Daktulosphaira vitifoliae). These rootstocks can also provide other benefits such as cold and drought tolerance, nematode and disease resistance, and control over vigor and phenology. Phylogenetic studies of the many Vitis species native to North America often disagree on the number of species and their boundaries, specifically in the Southwestern United States and Mexico. The wild vines are all dioecious and, with the exception of subgenus Muscadinia Planchon, interfertile – allowing for interspecific hybridization wherever ranges overlap. A better understanding of the relationships between North American Vitis species is needed to identify gaps in the current ex situ germplasm collections. Additionally, efforts must be made to safeguard dwindling populations of some species in their native environments. Conservation of these valuable genetic resources will ensure that grape breeders throughout the world have the necessary diversity to adapt to a changing environment.