低温预贮对冷藏桃果实冷害及能量水平的影响

研究了低温预贮对桃果冷害和能量水平的影响。桃果实先在12℃预贮6d，随后于0℃贮藏30d， 每隔5d测定果实褐变指数、硬度和出汁率等冷害指标、H+-ATPase、Ca2+-ATPase、琥珀酸脱氢酶、细胞色素氧化酶等线粒体呼吸代谢相关酶活性及能量相关物质ATP、ADP、AMP含量和能荷变化。结果表明：低温预贮处理可有效抑制果实H+-ATPase、和Ca2+-ATPase活性的下降，保持较高的琥珀酸脱氢酶和细胞色素氧化酶活性，使得ATP、ADP的含量及能荷保持较高水平，减少膜脂过氧化产物丙二醛(MDA)的积累和细胞膜透性增加，延缓果实出汁率下降，抑制果实褐变指数的升高。结果表明：低温预贮处理通过调节线粒体呼吸代谢酶活性，维持果实较高的能量水平，从而延缓膜脂过氧化进程，减轻果实冷害的发生。

Effect of Low Temperature Conditioning on Chilling Injury and Energy Status in Cold-Stored Peach Fruit

The effects of low temperature conditioning(LTC) on chilling injury and energy status in peach fruit were investigated.Peach fruit were pre-conditioned at 12 ℃ for 6 d and then stored at 0 ℃ for 30 d.Fruit browning index,firmness,extractable juice rate,the activities of mitochondria respiratory metabolism-related enzymes H+-ATPase,Ca2+-ATPase,succinic dehydrogenase(SDH) and cytochrome C oxidase(CCO),ATP,ADP and AMP contents,and energy charge were determined during storage at five-day intervals.The results indicated that LTC treatment effectively inhibited the decrease of H+-ATPase and Ca2+-ATPase activities,maintained higher activities of SDH and CCO and higher contents of ATP and ADP and energy charge,retarded the accumulation of malonaldehyde(MDA) and the increase in membrane permeability,delayed the decrease of extractable juice rate,and inhibited the increase of browning index.These results suggest that LTC treatment may maintain high energy status by regulating the activities of mitochondria respiratory metabolism-related enzymes,thereby delaying membrane lipid peroxidation and preventing the development of chilling injury of cold-stored peach fruit.