Evaluation of foliar resistance to Uncinula necator in Chines wild Vitis species

Resistance to grape powdery mildew (Uncinula necator BURR.) of 13 known Vitis species and 5 unclassified grapes native to China was evaluated. 88 clones were tested with natural infection and a subset of 34 were artificially inoculated during the years of 1991-1992. 68 clones showed resistance to U. necator. In general, we found clones of V. bryoniifolia, V. davidii, and V. piasezkii resistant to U. necator. However, intraspecific variations were observed. Results from this study indicate that Chinese native wild grapes may provide valuable germplasm resources for powdery mildew resistance