Application of antagonist Bacillus amyloliquefaciens NCPSJ7 against Botrytis cinerea in postharvest Red Globe grapes

We investigated the effects and possible mechanisms of Bacillus amyloliquefaciens NCPSJ7 against the gray mold caused by Botrytis cinerea in the postharvest Red Globe grapes. The disease incidence, lesion diameter, decay index, and some resistance-related enzymes were evaluated. The antioxidant capacity of grape treated with 1 x 10(4) CFU/ml B. cinerea alone and combined with 1 x 10(7) CFU/ml NCPSJ7 was also determined. The results showed that NCPSJ7 + B. cinerea reduced the disease incidence, lesion diameter, and decay index of postharvest grapes and enhanced the activities of polyphenol oxidase, peroxidase, chitinase, and beta-1,3-glucanase during different storage periods. Furthermore, the oxidative resistance, demonstrated by an escalating trend in the total phenolic content, DPPH free radical clearance rate, reducing power, and superoxide anion clearance rate after lesion presence, was improved. However, NCPSJ7 showed an inhibitory effect on gray mold, but resulted in the reduced antioxidant capacity in the grapes.