2011 Annual Report 1a.Objectives (from AD-416) To develop improved grapevine rootstocks resistant to aggressive virulent root-knot nematodes. 1b.Approach (from AD-416) Grapevine rootstock germplasm will be screened for resistance to aggressive virulent root-knot nematodes, crosses made, and resistant seedling selections identified through screening. 3.Progress Report Released three improved root-knot nematode resistant grape rootstock varieties, named Matador, Minotaur, and Kingfisher. Screened more than 3000 candidate grape rootstock seedlings for resistance to aggressive root-knot nematodes. We select only those seedlings which completely suppress nematode reproduction and show zero nematode egg masses. Selected seedlings are propagated and then planted into the vineyard. Tested the propagation ability of more than 50 selections (already tested once for nematode resistance). Cuttings produced callus, roots, or shoots in combination (or none of these). Refined and applied a technique for rapidly evaluating nematode resistance on replicated grapevine plants.