Search for, and Development of, Nematode Resistance in Grape Rootstocks

This year we have focused our attention on obtaining a broader genetic base for resistance to root-knot (Meloidogyne spp.) and dagger nematode (Xiphinema index) and broadening our search for resistance to the root lesion nematode (Pratylenchus vulnus), and the citrus nematode (Tylenchulus semipenetrans). We tested the durability of resistance to root-knot nematodes in the UCD-GRN series rootstocks under fluctuating soil temperature conditions. We have continued our tissue culture studies for better understanding of the nature of resistance to nematodes in different rootstocks. We have commenced monitoring ongoing field trials with the UCD-GRN series rootstocks to determine their performance in diverse situations. We have considerably expanded and improved accessibility to the database for plant resistance to nematodes and for selection of rotation and cover crops.