核桃果肉发育过程中糖含量及相关酶活性的变化

 以普通核桃为试材，研究了核桃果肉发育过程中糖含量及其相关酶活性的变化。结果表明:总糖含量呈现逐渐增长趋势，在果实油脂转化期(约花后90 d)达到极大值；淀粉含量呈波动状态。各种可溶性糖含量变化各异，果糖在果实发育前期含量最高，后期有所降低；葡萄糖含量变化不大; 蔗糖含量前期极低，后期逐渐增加。酸性转化酶和淀粉酶前期活性很强，后期降低；蔗糖合成酶(合成方向)和蔗糖磷酸合成酶的活性变化趋势相似，前期弱后期强。

Changes of Sugar Content and Sugar Metabolizing Enzyme Activities in the Flesh of Developing Walnut Fruit

The contents of total sugar, sucrose, glucose, fructose and the activities of sucrose-metabolizing enzymes containing acid invertase, sucrose synthase, sucrose phosphate synthase and amylase in the fruit flesh of Juglans regia L. were analyzed. The results showed that the highest content of total sugar was found in the late developmental stage, with the starch content being varied during fruit development and contents of soluble sugars changing according to the kinds of sugars. The fructose content gradually decreased in the late developmental stage, but the contents of sucrose and the glucose increased. The activities of acid invertase and amylase were higher at the early developmental stage than at the late developmental stage; and the activities of sucrose synthase and sucrose phosphate synthase showed a similar change pattern with lower activities at the early developmental stage and higher activities at the late developmental stage.