Effects of Harpin protein on fruit quality and shelf life of winter jujube (Ziziphus jujubaMill. cv. Dongzao)

The effects of HarpinXoo protein on fruit quality and shelf life of jujube (Ziziphus jujuba Mill. cv. Dongzao) were investigated in this study. Compared with water-treated control, spraying the winter jujube trees with HarpinXoo protein at 20 μg ml− 1 effectively improved the good fruit rate by 158.5%, significantly reduced the softening fruit rate by 54.6%, turning red index by 70.2% and rotten index by 89.1%, and depressed respiration rate by 45.5% and ethylene production by 48.7% after fruit had been stored for 80 days, resulting in effective extension of the postharvest life of fruit. Moreover, HarpinXoo protein treatment was beneficial for maintaining the quality of jujube fruit stored at 0°C, promoting the formation and retarding the decline of soluble sugar and vitamin C contents of fruit, which are important parameters of fruit quality during storage. After fruit had been stored for 80 days, the soluble sugar and vitamin C contents of treated fruit were more than twice those of control fruit. HarpinXoo protein has potential value for maintaining quality and extending the postharvest life of winter jujube fruit.