‘鸭梨’ב京白梨’杂交后代果实可溶性糖积累差异以及相关酶活性研究

The Difference of Soluble Sugar Accumulation and Related Enzymes Activities in Pear Fruit from Hybrid Offspring

以‘鸭梨’ב京白梨’杂交后代果实中分别表现高糖和低糖的个体GT-Y10和DT-Y168为试材,研究其果实发育过程中总糖、蔗糖、果糖、葡萄糖和山梨醇含量以及糖代谢相关酶活性的变化。结果表明:GT-Y10和DT-Y168中果糖含量最高,分别占总糖含量的45.77%和50.98%,山梨醇含量次之,蔗糖含量相对较低。成熟时,GT-Y10的果糖含量显著低于DT-Y168,而蔗糖、葡萄糖、山梨醇乃至总糖含量均显著高于DT-Y168。GT-Y10和DT-Y168蔗糖含量差异主要由SS(合成方向)引起;葡萄糖和果糖的差异主要由于NAD+-SDH和NADP+-SDH活性的差异引起,同时受AI、NI和SS(分解方向)的影响;NAD+-SDH和NADP+-SDH还造成山梨醇含量的差异。

Two individuals （ GT-Y10, DT-Y168 ）, showing comparative higher or lower sugar content with fruit respectively, from the population of ＇Yali＇×＇ Jingbaili＇ were taken as materials. The contents of total sugar, sucrose, fructose, glucose, sorbitol and the activities of sugar related metabolizing enzymes were analyzed and compared. Results showed that the content of fructose in GT-Y 10 and DT-Y 168 was the highest, and accounted for 45.77% and 50.98% of total sugar content; The content of sorbitol following as the second, and the content of sucrose was comparative lower. At the stage of fruit ripening, the content of fructose in GT-Y 10 was lower than that of DT-Y168, while the content of sucrose, glucose, sorbitol were higher in contrary, and resulted in total sugar difference between GT-Y10 and DT-Y168. The key enzyme that resulted in the difference of sucrose content between GT-Y10 and DT-Y168 was the sucrose synthase （synthetic activity）, the difference of glucose and fructose content between GT-＋ 10 and DT-Y 168 weremainly resulted by NAD＋-dependent sorbitol dehydrogenase and NADP＋-dependent sorbitol dehydro- genase, meanwhile it also affected by acid invertase, neutral invertase and sucrose synthase （cleavage activity） . The activity ofNAD＋-dependent sorbitol dehydrogenase and NADP＋-dependent sorbitol dehydro- genase also made contribution to the difference of sorbitol content between GT-Y 10 and DT-Y 168.