中文摘要：

为了探明根域限制提高葡萄果实糖度的机制,用5年生‘峰后’葡萄为材料,在果实成熟期用＂浆果杯＂技术比较了根域限制处理与对照的果实韧皮部糖卸载的日变化。结果表明,葡萄果实韧皮部糖卸载在一天中有3次高峰,分别出现在上午、下午和晚上（9：00、17：00和21：00左右）。上午卸载量大,其峰值分别为下午和晚上的2.1和1.4倍左右;根域限制处理果实的糖卸载量始终高于对照,约为对照的1.5倍,并且上午糖的快速卸载提前了3h,峰值为对照的2.0倍。给＂浆果杯＂中的糖卸载缓冲液添加ABA、EGTA,促进了糖卸载,但添加EB却抑制糖卸载。表明葡萄果实韧皮部糖卸载需要消耗能量,根域限制促进了葡萄果实韧皮部的糖卸载,并可能与其诱导ABA含量的升高有关。

英文摘要：

Sugar content in grape berry could be significantly improved under root restriction. To unravel the mechanism of improved sugar content, we studied the effects of root restriction on diurnal changes of sugar phloem unloading in grape berry by using with ＂berry-cup＂ technique in 5-year-old ＇Fenghou＇ grapevine during ripening period. The results showed that sugar phloem unloading in berry exhibited three peaks in both the control and root restriction treatment, which appeared at about 9- 00, 17- 00 and 21： 00. In the root restriction, the peak value at 9. 00 was about 2.1 and 1.4 fold of those at 17. 00 and 21 ：00, respectively. Compared with the control, the amount of sugar phloem unloading in berries under root restriction were about 1.5 fold higher through the experiment. In addition, the abundant sugar unloading in the morning was 3 hours earlier and the peak was 2.0-fold of the control. Furthermore, the addition of ABA and EGTA to buffer solution in ＂berry-cup＂ promoted sugar phloem unloading, whileEB had adverse effects. The above evidences demonstrated that the process of sugar unloading in berry consumed energy and it might be related to the enhanced ABA content in grape berry under root restriction.