黄瓜叶片和韧皮部汁液中碳水化合物及相关酶的日变化  

Diurnal Changes of Non-structural Carbohydrates and Relative Enzymes in Leaves and Phloem Sap of Cucumber

作　　者：蒋亚华[1] 缪旻珉[1] 陈学好[1] 曹碚生[1] 

机构地区：[1]扬州大学农学院园艺系,江苏扬州225009

出　　处：《园艺学报》2006年第3期529-533,共5页Acta Horticulturae Sinica

基　　金：江苏省自然科学基金资助项目(BK2002403);江苏省高校自然科学基金项目(04KJA210158)

摘　　要：以黄瓜叶片和韧皮部汁液为对象,研究1个昼夜周期中各种碳水化合物含量及相关酶活性的变化。结果表明夜间至上午10:00,葡萄糖和果糖是叶片中主要的可溶性糖,而下午13:00至16:00,水苏糖成为成熟叶片中含量最高的可溶性糖,这种变化主要由叶片中水苏糖含量剧烈的昼夜变化引起;当黄瓜同化物从源叶向外运输时,韧皮部汁液中的可溶性糖以水苏糖为主,运输完毕后则以蔗糖为主;黄瓜成熟叶片在夜间以淀粉、葡萄糖、果糖、水苏糖、蔗糖等各种形式贮藏尚未运出的同化物,而此时韧皮部汁液中葡萄糖、果糖、水苏糖的含量极低,可能有特定的源库调节机制阻止叶片中的可溶性糖在夜间进一步向韧皮部中装载。Diurnal patterns of non-structural carbohydrates and relative enzymes in mature leaves and phloem sap in cucumber （Cucumis sativus L. ） were studied. The results showed that glucose and fructose are primary soluble sugars from night to 10：00 a.m. in mature leaves, but during 13：00 - 16：00 p. m. , stachyose becomes the most abundant oligosaccharide, this diurnal change is mostly due to the tempestuous fluctuation of stachyose concentration in mature leaves. During photoassimilate transportation, the primary soluble sugar in phloem sap is stachyose. When transportation is finished, sucrose becomes the main sugar in phloem sap. Cucumber leaves may store photoassimilate in the forms of starch, glucose, fructose, stachyose and sucrose at night. The concentrations of glucose, fructose and stachyose in phloem sap are much lower than in leaves at that time. There may be some unique mechanisms modulating source-sink translocation by which soluble sugars in leaves were prevented from loading into the phloem further during night.

关 键 词：黄瓜 碳水化合物 日变化 

分 类 号：S642.2[农业科学—蔬菜学]