Investigating genetic resistance to foliar phylloxera in cold hardy hybrid grapes

Grapevine phylloxera has been a major pest for viticulturists since the introduction of the insect from North America to Europe where it decimated the roots of the highly susceptible Vitis vinifera vines. Daktulosphaira vitifoliae (Fitch) is an obligate parasite on Vitis spp. and has moved on vines to important grape production regions worldwide. This pest co-evolved with N. American Vitis, and genetic resistance has been identified a number of these species.  Resistant hybrid rootstocks were used extensively to revitalize the industry, and continue to play a major role for pest control. Minnesota cold-hardy hybrids vary in their susceptibility to phylloxera and little research has been conducted to quantify the effects of leaf infestation, determine the genes involved in resistance, or characterize the resistance response. (Funded by Minnesosta Department of Agriculture Crop Grant Program)