根域限制对‘巨玫瑰’葡萄果实可溶性糖含量及相关代谢酶活性的影响

 以‘巨玫瑰’葡萄（Vitis vinifera L. × V. labrusca L.）为试材，从始熟期开始研究了根域限制栽培对果实可溶性糖积累及相关代谢酶活性的影响。结果表明：‘巨玫瑰’葡萄果实中主要以葡萄糖和果糖积累为主。从始熟期开始果实中的葡萄糖和果糖含量持续增加，与此同时，酸性转化酶（AI）的活性也随果实发育进程而逐步增强。AI活性与果实中含量最多的葡萄糖和果糖含量显著相关。中性转化酶（NI）和蔗糖合成酶（SS）的分解方向的活性只是在始熟期3周后开始增加，且活性低于AI。蔗糖合成酶（SS）的合成方向和蔗糖磷酸合成酶（SPS）的活性在始熟期开始后稍有增加，此后保持平稳，且活性远远低于蔗糖分解相关酶AI、NI和SS的分解方向活性。根域限制栽培可以显著提高‘巨玫瑰’果实中可溶性糖的含量、糖积累期间的AI活性和成熟时的NI活性，但对其他酶活性影响不显著。由此推断AI是葡萄果实糖积累的最重要的调节因子，也是根域限制提高果实糖含量的关键代谢酶。

Effects of Root Restriction on Soluble Sugar Contents and Related Enzyme Activities in 'Jumeigui'Grape Berries

Jumeigui’grape（Vitis vinifera L. × V. labrusca L.）was subjected to root restriction to study the metabolic mechanism of soluble sugar accumulation in grape berries during the berry development from veraison to maturation. The results showed that the main sugars accumulated in ‘Jumeigui’grape were glucose and fructose. From the beginning of veraison，contents of glucose and fructose in berries increased continuously，and meanwhile acid invertase（AI）activity increased gradually with berry development. What’ more，AI activity was significantly correlated with the contents of glucose and fructose which are the most important soluble sugars in the grape berry. The activity of neutral invertase（NI）and sucrose synthase（SS）activity in the sucrose cleavage direction increased 3 weeks after veraison and lower than that of AI. The activity of enzymes for sucrose synthesis including sucrose synthase（SS）in the sucrose synthetic direction and sucrose phosphate synthase（SPS）increased slightly just at the early veraison and then kept constant，and was lower than that of SS in the sucrose cleavage direction，AI and NI related to sucrose cleavage. The root restriction could increase the content of soluble sugars in grape berries and enhance AI activity during the period of sugar accumulation and NI activity at harvest. Therefore，we speculate that AI is the most important regulator for sugar accumulation and also the key enzyme accounting for increased sugar content by root restriction cultivation.