Evaluation Of Grape Genotypes Against Botrytis Cinerea And Responses Of Antioxidant Enzymes,reactive Oxygen Species And Jasmonic Acid In Host Plants

1.Botrytis cinerea is a necrotrophic fungal phytopathogen with devastating effects on many Vitis genotypes.Here,a screening of 81 Vitis genotypes for leaf resistance to B.cinerea 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'(Vitis davidii),and the HS genotype ‘Riesling'(V.vinifera L.),to elucidate mechanisms of host resistance and susceptibility against B.cinerea,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 B.cinerea.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 B.cinerea infection in grape,which can be valuable for breeders by providing information for selecting suitable germplasm with enhanced disease resistance.2.In this study,berries of 41 Vitis genotypes were evaluated for resistance to B.cinerea.Evaluation revealed that four genotypes were highly resistant(HR),eight resistant(R),eighteen susceptible(S)and eleven highly susceptible(HS)genotypes.We Further,studied that highly resistant(HR)genotype “Dong fang zhi xing” revealed stronger resistance than in highly susceptible(HS)“Gold finger” by comparing the fungal growth,reactive oxygen species(ROS)responses,jasmonic acid(JA)levels,anti-oxidants,e.g.,Peroxidase(POD),Superoxide dismutase(SOD)and Malondialhydrate(MDA)content changes after infection with B.cinerea.Our results confirmed that the elevated resistance of ‘Dong fang zhi xing' was due to weak fungal development,low ROS production,timely elevation of antioxidative functions,and high JA levels.Moreover,HS Gold finger severed infection and sustained ROS production may be due to its relatively unchanged anti-oxidative activities and low JA level.Our results could help grape breeders to select suitable germplasm for future research work.3.Botrytis cinerea is a devastating necrotrophic fungal phytopathogen.Two grape cultivars were evaluated for leaf resistance to B.cinerea.Detached leaf assays revealed stronger resistance in Marselan(Vitis vinifera)than in Blue French(V.vinifera).Explanations behind B.cinerea resistance in Marselan and susceptibility in Blue French were further investigated by comparing the fungal growth,reactive oxygen species(ROS)responses and anti-oxidative system changes between the two cultivars after infection with B.cinerea.Our results confirmed that the high-level resistance of ‘Marselan' can be attributed to insignificant fungal development,low ROS production and timely elevation of antoxidative functions.Moreover,‘Blue French' suff ered massive infection and sustained ROS production because of it's relatively,inactive anti-oxidant.However,this finding needs to be resolved by further elucidating the molecular mechanisms.This study provides understanding of B.cinerea infection of grapes and thus could help breeder's select suitable germplasm for future research.