‘石硖’龙眼果皮发育过程中糖代谢及相关酶活性变化

Changes of Sugar Metabolism and Related Enzyme Activities in the Development of Pericarp of 'Shixia' Longan

为探索龙眼果皮发育过程中糖分积累以及相关酶活性的变化规律,以‘石硖’龙眼(Dimocarpus longan Lour.cv‘shixia’)为试材,对花后45 d到果实成熟期间果皮质量、厚度,果糖、葡萄糖、蔗糖含量,以及蔗糖代谢相关酶活性水平进行测定。结果表明,果实发育后期,果皮质量增加的速度变缓,果皮厚度则表现为由厚到薄的变化模型。糖分水平显示,果实发育过程中果皮可溶性糖主要包括果糖、葡萄糖和蔗糖,同期果糖含量远远高于葡萄糖,蔗糖含量较低。蔗糖代谢酶活性表明,龙眼果皮中NI和SS(分解方向)活性较高,为调控‘石硖’龙眼果皮糖代谢的主要酶类,SPS、SS(合成方向)活性则较低,为果糖和葡萄糖生成发挥非常重要的作用。

In order to clear the variations both sugar accumulate and sugar metabolizing enzymes activities in longan pericarp in the process of fruit development stage, the weight and thickness of the pericarp, the concentration of fructose, glucose and sucrose, and the activities of the sucrose metabolizing enzymes were all measured in the pericarp of ＇shixia＇ longan during the stage that 45 d after flowering to fruit maturity. The results showed the growth rate of pericarp weight was from quickly to slowly and the thickness development model was thin^thick^thin. The sugar mainly included fructose, glucose and sucrose. The content of fructose was significant higher than glucose, however the content of sucrose was at low level during the whole growing period. The activities of NI and SS （the decomposition direction） maintained higher level which were the main enzyme mediating the sugar accumulated in the periearp, SPS and SS （the composition direction） with lower activity played very important role in accumulation of fructose and glucose that activities were lower.