1a.Objectives (from AD-416)
Breed, evaluate, and introduce rootstocks that are resistant to root-knot nematodes and adapted to California's growing season.
1b.Approach (from AD-416)
Screen seedlings for nematode resistance, select superior resistant seedlings, advance selections to field testing and further evaluation, and identify parents for the next round of crossings
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.