Screening Genotypes for Responses to and Evaluation of Antioxidant Enzymes, Reactive Oxygen Species and Jasmonic Acid in Resistant and Susceptible Hosts.

is a necrotrophic fungal phytopathogen with devastating effects on many genotypes. Here, a screening of 81 genotypes for leaf resistance to . revealed two highly resistant (HR), twelve resistant (R), twenty-five susceptible (S) and forty-two highly susceptible (HS) genotypes. We focused on the HR genotype, 'Zi Qiu' (), and the HS genotype 'Riesling' (. ), to elucidate mechanisms of host resistance and susceptibility against . , using detached leaf assays. These involved a comparison of fungal growth, reactive oxygen species (ROS) responses, jasmonic acid (JA) levels, and changes in the anti-oxidative system between the two genotypes after inoculation with . . Our results indicated that the high-level resistance of 'Zi Qiu' can be attributed to insignificant fungal development, low ROS production, timely elevation of anti-oxidative functions, and high JA levels. Moreover, severe fungal infection of 'Riesling' and sustained ROS production coincided with relatively unchanged anti-oxidative activity, as well as low JA levels. This study provides insights into . infection in grape, which can be valuable for breeders by providing information for selecting suitable germplasm with enhanced disease resistance.