Controlling Of Skin Browning Of Pear (cv. Pingguoli) During Storage With Preharvest Gibberellin Spray, Postharvest Hot Water Dipping And Individual Film Wrapping Single Or Combination

Skin browning of Pear (Pingguoli) is a major post-harvest physiological disease, which significantly reduces the appearance value of fruit by showing many dark brown spots. In this study, preharvest gibberellin(GA₃)sprays at 50mg/L, postharvest hot water dipping (HWD) and individual film wrapping (IFW) were employed with single and combined treatments for evaluating the effect of treatments on index of skin browning, antioxidant properties, epidermal ultrastructure and quality of fruit during ambient temperature (15±5℃) and low temperature (0±1℃) storage. The results showed as below:1. The single ( GA₃, HWD, IFW ) and combination treatments (GA₃ +HWD, GA₃ +HWD+ IFW, HWD+ IFW) significantly decreased the incidence of skin browning of fruit during ambient and low temperature storage. The treatment of GA₃ +HWD showed the best control, incidence of skin browning was 20.9% after 35d during ambient storage and 30.8% after 120d low temperature storage of the control. HWD treatment followed the second.2. Both single and combination treatments reduced the accumulation of malondidehyde (MDA), maintained cell membrane integrity and enhanced POD, CAT, APXå’ŒSOD activities, decreased PPO activity. The treatment of GA₃ +HWD showed the best effect on such parameters.3.The treatmen of GA₃ +HWD reduced fruit epidermal cracks, significantly increased the thickness of skin tissue, had visible boundaries of horny and wax layer, cell wall structural integrity, higher electron density, primary wall on both sides closed to the middle lamella, maintained the integrity of the cell structure.4. Both single and combination treatments enhanced soluble solids content to some extent, maintained higher firmness, notably increased soluble solids content / titratable acid, improved the quality of fruit. The treatment of GA₃ +HWD had the best effect on quality of fruit.It is suggested that the treatmen of GA₃ +HWD effectively decreased the incidence of skin browning of pear during ambient and low temperature storage by enhancing activity of antioxidation enzymes, maintaining membrane permeability and increasing the thickness of epidermis. It could be as an effective measure to control the skin browning of pear.