Breeding grapevine rootstocks for resistance to soil-borne pests and diseases

Objectives: Continue a rootstock breeding program initiated in the Department of Viticulture and Enology, University of California, Davis in 1988, addressing resistance to soil-borne pests and diseases. Evaluate seedling populations from crosses with Muscadinia rotundifolia and a range of Vitis species of North American, Middle Eastern, and Asian origin for resistance to phylloxera, fanleaf degeneration, and root knot nematodes, and for viticultural characteristics such as propagatability. Increase of understanding of the nature of phylloxera and fanleaf degeneration resistance under Californian conditions, by utilizing tissue culture and whole plant methods, and apply the knowledge to seedling evaluations. Produce additional crosses, as indicated by preliminary information from seedling screenings, to further emphasize ease of propagation and enhanced resistance. Begin field evaluation of selected genotypes leading to the release of new rootstock cultivars. This project is a part of a broadly focused rootstock breeding program. This specific project emphasizes rootstocks tailored for use with wine grapes. Many of the objectives are shared with a similar project jointly funded by the California Table Grape Commission and the California Raisin Advisory Board which emphasizes table and raisin grape rootstock development.