李果实成熟软化过程中生理特性及乙烯合成变化的研究

以乙烯合成途径为线索,研究李(Prunus domestica L.)果实成熟软化过程中硬度、可溶性固形物、可滴定酸、乙烯释放量、氨基环丙烷羧酸(ACC)和丙二酰氨基环丙烷羧酸(MACC)含量以及ACC合成酶(ACS)和ACC氧化酶(ACO)活性等指标的变化,探讨乙烯在李果实成熟软化中的作用。结果表明:李果实成熟软化过程中,硬度和可滴定酸的含量逐渐降低,可溶性固形物含量增加。李果实成熟期的软化启动阶段,乙烯释放量、ACC含量、ACS和ACO活性增强缓慢,此时乙烯释放量也比较低,ACS和ACO的活性都受到一定程度的抑制,在成熟过程中三者高峰值同时出现在软化后期。证明李果实成熟期的软化启动阶段,乙烯并非是软化启动因子,可能还存在其他的启动相关因子。

Study on the physiological characteristics and ethylene production during plum fruit ripening and softening

Taking ethylene biosynthesis as a clue,changes of firmness,TSS and TA content,ethylene production,ACC and MACC content,the activity of ACC oxidase and ACC synthase were determined and the effect of ethylene on plum fruit ripening and softening were discussed.The results showed that firmness and TA content decreased and TSS increased during plum fruit ripening and softening.In the start-up stage of softening,ethylene production as well as ACC oxidase and ACC synthase activity increased slowly and linear correlations can be seen among them.The peak of ethylene appeared in the later stage of softening.The study proved that ethylene was not the promoter for plum softening,and other factors for promoting plum softening still existed.