Enhanced resistance of jujube (Zizyphus jujuba Mill. cv. Dongzao) fruit against postharvest Alternaria rot by β-aminobutyric acid dipping

Abstract Considerable losses of jujube ( Zizyphus jujuba Mill. cv. Dongzao) fruit caused by Alternaria rot often occurred during storage. In order to evaluate effects of β-aminobutyric acid (BABA) on the infection on jujubes by Alternaria alternata , the fruit were dipped in BABA solutions and then inoculated with the pathogen. Results showed that BABA dipping at concentrations of 0.5, 1.0 and 2.0 g L −1 significantly ( P A. alternata , whereas BABA did not affect conidial germination and mycelial growth of the pathogen in vitro . In addition, BABA reduced natural infection and postharvest softening of jujubes during the storage at 0 °C and 85–95% relative humidity. Biochemical evaluations revealed that BABA enhanced activities of defence-related enzymes including peroxidase, phenylalanine ammonia-lyase and chitinase of the fruit. BABA altered antioxidant metabolism to trigger disease resistance by significantly ( P