1-甲基环丙烯采后处理对樱桃番茄果实成熟过程的影响

摘要

研究了不同浓度(0、0.035、0.07和0.11μL/L)的乙烯受体竞争性抑制剂1-甲基环丙烯(1-MCP)采后处理对绿熟期樱桃番茄的乙烯合成、果实软化、果实色素(叶绿素、茄红素、β-胡萝卜素)含量消长的影响.0.07 μL/L及其以上浓度的1-MCP降低了前期乙烯合成,同时推迟了乙烯释放高峰,但0.035 μL/L浓度的1-MCP处理并不能抑制内源乙烯合成.1-MCP显著延迟了果实软化和叶绿素降解,但并不影响这两个过程的启动.茄红素合成的启动和积累均受到了1-MCP抑制,而1-MCP并不推迟β-胡萝卜素合成的启动,只抑制其积累.这些结果提示了乙烯调节成熟生理过程的不同机制.对于绿熟期的樱桃番茄,0.07～0.11μL/L的1-MCP是实用的有效处理浓度.1-MCP有效浓度可能用于了解果实的乙烯受体水平和乙烯敏感性.%The responses of cherry tomato(Lycopersicon esculentum var. cerasiforme) fruits to post-harvest treatment with 1-MCP were investigated.The maturity stage at which 1-MCP application is most effective in delaying the ripening process was determined, and then the effects of different concentrations (0, 0.035, 0.07 and 0.11 μL/L) of 1-MCP on ethylene production, fruit softening, chlorophyll, lycopene and carotenoids contents of mature green (MG)cherry tomato fruits were assessed. 1-MCP at 0.07 and 0.11 μL/L reduced fruit C2H4 production, delayed the C2H4 peak at ambient temperature. Although 1-MCP at 0.035 μL/L was effective in retarding fruit ripening,it did not suppress endogenous ethylene production.Fruit softening was suppressed by 1-MCP, but its initiation was not affected by 1-MCP. The rate of chlorophyll degradation and its pattern of change with time,and the initiation of lycopene biosynthesis as well as its accumulation were all affected by 1-MCP, but only the accumulation of carotenoids was suppressed. Accumulation of lycopene and carotenoids was almost permanently hampered by 1-MCP at 0.07 μL/L or higher concentrations, and fruit color could not reach the control level even 2 weeks after 1-MCP treatment,indicating the close association of the metabolism of these pigments with ethylene perception. Since the concentration of 0.11 μL/L of 1-MCP was so high that it did not elicit additional response very much than 0.07μL/L, these concentrations were considered to be practically effective concentrations for cherry tomato at MG stage. The effective 1-MCP concentrations might provide a useful reference to the levels of ethylene receptors as well as ethylene sensitivity in a specific fruit at given development stage.