Resistance of Cucurbita moschata and C. pepo Lines to a Powdery Mildew Causal Organism

Abstract

ABSTRACTThe causal agent of powdery mildew disease inflicts severe damage on cucurbits in production areas throughout the world. Local lines may exhibit different rates of resistance, and this was examined in some local cucurbit lines. Resistance was based on the amount of leaf area affected. Differences among lines occurred: most lines had low affected leaf area (avg. 4.85%), but line G3 had a highly affected leaf area (37.73%) that was higher than most other genotypes. Tolerance in plants could be used in developing improved cultivars. The significance of resistance, and its durability for plant production, in all countries, especially in developing countries, justifies breeding for resistance. It appears that G7 can be used as a source in breeding to develop resistant cultivars because it appears to be superior due to low affected area and high general combining ability in crosses with other elite lines.