不同黑皮病发病程度的‘五九香’梨生理生化差异

摘要

The superficial scald of peel often appears in 'Wujiuxiang' pear after cold storage. In order to explain the incidence cause, 'Wujiuxiang' pear was used as material and the changes of the pear firmness, soluble solids content, crfarnesene, conjugated triene, hydrogen peroxide (H2O2) and total phenolic, and polyphenol oxidase (PPO) activity were investigated in various grade of superficial scald after cold storage and shelf life. The results indicated that the content of crfarnesene and PPO activity were significantly decreased, while content of conjugated triene, H2Q2 and total phenolic, and relative conductivity in peel were gradually increased with the increase of scald grade. After storage at (20±2) ℃ for 3 d, the superficial scald fruit firmness and content of soluble solids, crfarnesene, conjugated triene and total phenolic were decreased. However, the relative conductivity and H2O2 content were significantly increased. In conclusion, the grades of superficial scald were related to crfarnesene, conjugated triene, mem-brane permeability and content of H2O2 in peel.%‘五九香’梨冷藏后极易发生黑皮现象.为解释其发病机制,以不同程度患黑皮病的‘五九香’梨( Pyrus communis L.‘Wujiuxiang')为材料,分析了果实硬度、可溶性固形物含量(SSC),以及果皮中α-法尼烯、共轭三烯、H2O2、多酚氧化酶(PPO)以及总酚等指标的差异.结果表明:随着黑皮病发病程度加重,果皮α-法尼烯逐渐减少,而共轭三烯、H2O2和总酚含量逐渐增加,细胞膜透性上升,PPO活性下降.在(20±2)℃下贮藏3d后,发病果实的硬度、可溶性固形物含量、果皮α-法尼烯、共轭三烯以及总酚含量显著降低,而相对电导率、H2O2含量和PPO活性显著增加.说明‘五九香’梨黑皮病发生与果皮中共轭三烯、膜透性和H2O2含量增加密切相关.