摘要
[Objective] This study was conducted to evaluate the effect of 1-methylcy- clopropene （1-MCP） on fruit firmness, and the activity of the enzymes involved in ethylene metabolism and membrane lipid peroxidation. [Method] The nearly ripe fruits of the papaya cultivar Risheng were randomly assigned to one of four groups. Two groups were treated under hypobaric and hypoxic （HH） atmosphere condition for six hours, and immediately soaked in deionized water （HH alone）, or fumigated with 2.0 mg/L 1-MCP （HH＋I-MCP） for 24 h. The other two groups untreated under HH condition were also soaked in deionized water （negative control）, or fumigated with 2.0 mg/L 1-MCP （1-MCP alone） for 24 h. After that, the fruits of all the four treatments were stored at room temperature （23＋1） ℃. Cell membrane permeability, fruit firmness, respiration rate, ethylene release rate, SOD activity, POD activity, CAT activity, MAD content and LOX activity were measured once every three days during storage. [Result] Treatment with 1-MCP delayed the occurrence of the peaks of respiration rate and ethylene release rate, significantly reduced the accumulation of malondialdehyde （MDA）, and inhibited the decrease in papaya fruit firmness. Compared with the control, 1-MCP treatment significantly increased the SOD （su- peroxide dismutase）, POD （peroxidase） and CAT （catalase） activity, reduced the ac- tivity of lipoxygenase （LOX）, a product of lipid peroxidatlon in membranes, and in- hibited ethylene biosynthesis, thus delaying the aging process and prolonging the storage life of papaya fruits. [Conclusion] The results will provide a theoretical basis for analvzina the key factors controllinq postharvest maturity and aging of papaya fruits.
[目的]研究1-MCP处理对果实硬度及乙烯代谢和膜脂过氧化相关酶的的影响。[方法]以"日升"番木瓜为试材,用低压低氧(HH)处理并进行1-MCP熏蒸后室温下贮藏。[结果]1-MCP处理推迟呼吸和乙烯峰的出现,有效地减少了脂膜过氧化物产物丙二醛(MDA)的积累,抑制番木瓜果实硬度的下降。与对照比较,1-MCP处理显著提高了SOD(超氧化物歧化酶)、POD(过氧化物酶)和CAT(过氧化氢酶)的活性,降低了脂膜过氧化过程中脂肪氧合酶(LOX)活性,延缓番木瓜果实衰老进程,并抑制了乙烯的生物合成过程,延长了贮藏时间。[结论]该研究为番木瓜果实采后衰老的关键控制因子研究提供了理论依据。
基金
国家热带作物种质资源平台建设项目(2014-073)~~
