越瓜果实发育过程中糖的变化与相关酶活性的关系

Relationship between Sugar Content Change and Interrelated Enzyme Activity in Crisp Melon Fruit Development Process

以从各地搜集的6个越瓜品种为试材,对越瓜果实糖含量及蔗糖代谢相关酶进行了研究。结果表明:不同越瓜品种之间糖含量差异较大,凤台越瓜、田集越瓜、刘集越瓜3个品种可溶性固形物含量及糖含量较高;随着果实的发育蔗糖磷酸合成酶活性呈递增趋势,且在果实各个发育期田集越瓜的蔗糖磷酸合成酶活性均最高;而转化酶活性则随着果实发育呈下降趋势,凤台越瓜和田集越瓜的酸性转化酶及中性转化酶活性在各个发育期均最低;中性转化酶在毛集越瓜、潘集越瓜、青皮越瓜、刘集越瓜中相对较高,且随着果实发育活性下降,至果实成熟时活性达到最小值;除刘集越瓜外,其他品种的蔗糖代谢酶活性在果实不同发育期均没有明显变化。以上结果表明,不同越瓜品种蔗糖含量差异是由蔗糖磷酸合成酶、酸性转化酶和中性转化酶活性共同决定的,其中酸性转化酶在越瓜蔗糖积累中占主导地位。

We collected 6 crisp melon(Cucumis melo L.var.conomon Makino)varieties as experiment materials and studied the sucrose content of crisp melon fruit and sucrose metabolism enzymes.The results showed that there were big differences in sugar contents of different crisp melon varieties.The soluble solid contents and sugar contents of 3 varieties'Fengtaiyuegua','Tianjiyuegua','Liujiyuegua'were higher.The sucrose phosphate synthase activity became higher and higher as the fruit grew and matured,and the enzyme activity was the highest in'Tianjiyuegua'.While the invertase activity became lower and lower along with the fruit development.The activities of acid invertase and neutral invertase were the lowest in'Fengtaiyuegua'and'Tianjiyuegua'during various development stages.The activities of neutral invertase were high in'Maojiyuegua','Panjiyuegua','Qingpiyuegua','Liujiyuegua',and decreased with the fruit development.There were no obvious changes in other varieties sucrose metabolism enzymes activities in crisp melon fruit expect'Liujiyuegua'.These results indicated that the differences in sugar contents of different crisp melon varieties was determined by the activities of sucrose phosphate synthase,acid invertase and neutral invertase,and the acid invertase took the leading place.