坐果剂对甜瓜果实糖分和蔗糖代谢酶的影响

【目的】探讨坐果剂与人工授粉处理对甜瓜果实发育过程中糖分积累及蔗糖代谢关键酶活性影响的差异性，为甜瓜的优质栽培提供理论依据。【方法】以“早蜜”厚皮甜瓜为试验材料，以人工授粉为对照，喷施“福美特”和“帝豪”2种坐果剂，于处理后每5 d取样1次，测定甜瓜果实可溶性总糖、果糖和蔗糖含量以及4种蔗糖代谢关键酶活性的动态变化。【结果】厚皮甜瓜果实的可溶性总糖、蔗糖和果糖含量变化均表现为前期积累缓慢，后期积累迅速,并且在花后20 d有1个明显的“拐点”；前期以积累果糖为主,成熟期则以积累蔗糖为主。在果实发育的早期，以蔗糖分解转化酶活性较高，进入成熟期则以合成酶活性较高。喷施“福美特”显著增加了甜瓜果实的可溶性糖和蔗糖含量，喷施“帝豪”处理与对照差异不显著。喷施“福美特”可显著增强果实发育后期的蔗糖合成酶活性，但转化酶活性有所降低。【结论】喷施坐果剂能够改变果实糖分的积累，且会对果实蔗糖代谢相关酶活性产生影响，适量的坐果剂能够提高甜瓜果实的品质。

Effects of fruit-bearing agents on the changes of the sugar accumulation and sucrose-metabolizing enzymes in muskmelon (Cucumis melon)

【Objective】 This experiment was carried out to elucidate the different effects of the fruit-bearing agents and artificial pollination on sugar accumulation and sucrose-metabolizing enzymes during the developing period of muskmelon fruit,in order to provide a theoretical basis on the quality cultivation of melon.【Method】 With "Zaomi" as the experimental material,the changes of sugar accumulation and activities of enzymes related to sucrose metabolism were compared in the development of muskmelon under three conditions,artificial pollination,spraying "Fumeite" fruit-bearing agent and "Dihao" fruit-bearing agent.The physiological indexes were exploited every 5 days.【Result】 The results showed that "Zaomi" had high content of sugar and fructose,but sugar mainly accumulated in maturing stage.And there was an obvious "knee point" 20 days after blooming.There was a higher activity of sucrose invertase enzyme in the early fruit development and higher synthase activity in the mature.Muskmelon fruit that used the fruit-bearing agent of "Fumeite" had a significant increase in soluble sugar content and sugar content,while the difference was not obvious between "Dihao" and artificial pollination.The sucrose synthase activites increased significantly and the inverts activities reduced under the condition of using "Fumeite" in the later developing period.【Conclusion】 Using the fruit-bearing agents can change the sugar accumulation and has an impact on sucrose metabolism-related enzyme activities.Proper fruit-bearing agents can improve the quality of melon.