‘新新2号’核桃果实发育进程中碳水化合物积累与变化

Carbohydrate Accumulation and Change During the Development of Juglans. regia ‘Xinxin2’ Fruit

以新疆南疆盆地核桃主栽品种‘新新2号’(Juglans regia ‘Xinxin2’)为研究对象,研究果实不同生长发育时节其青皮和种仁中葡萄糖、蔗糖、果糖、淀粉含量和中性转化酶(NI)、酸性转化酶(AI)、蔗糖合成酶(SS)、蔗糖磷酸合成酶(SPS)的活性变化。结果表明:花后45~70 d,果实处于速生生长期,青皮中果糖和葡萄糖含量高于蔗糖和淀粉,AI活性保持较高水平,种仁中果糖含量高于蔗糖、葡萄糖和淀粉含量;花后90~110 d,果实处于油脂转化期,青皮蔗糖含量和SS、SPS活性迅速升高,种仁蔗糖和葡萄糖含量高于果糖含量,SS和SPS活性急剧升高,NI和AI活性保持较低水平。相关分析结果显示,青皮蔗糖含量与SS活性、SPS活性呈显著正相关(P<0.05),果糖含量与AI活性呈显著正相关(P<0.05);种仁淀粉含量与青皮淀粉含量呈显著正相关(P<0.05),与青皮AI活性呈显著负相关(P<0.05)。在速生生长期,核桃果实青皮中的蔗糖在高活性的AI作用下被分解成葡萄糖和果糖,为果实细胞分裂和形态构建提供物质和能量基础;在油脂转化期,核桃果实青皮和种仁中蔗糖的积累是高活性的SS、SPS和低活性的AI、NI共同作用的结果。

The main walnut cultivar ‘Xinxin2’(Juglans.regia) in Southern Xinjiang Basin was used as the research object to study the the changes in contents of glucose,sucrose,fructose,starch and the activities of neutral invertase(NI),acid invertase(AI),sucrose synthase(SS) and sucrose phosphate synthase(SPS) in green peel and kernels sampled at different growth stages.The results showed that 45-70 days after flowering(DAF),the fruit was in the fast-growing period;in green peel,the contents of fructose and glucose were higher than those of sucrose and starch,and AI activity remained high;in kernels,the fructose content was higher than those of sucrose,glucose and starch.90-110 DAF,the fruit was in the stage of oil transformation;in green peel,the sucrose content and the activities of SS and SPS increased rapidly;in kernels,the contents of sucrose and glucose were higher than that of fructose,and the activities of SS and SPS increased sharply,while the activities of NI and AI remained low.The results of correlation analysis showed that sucrose content in green peel was positively correlated with the activities of SS and SPS(P<0.05),fructose content was positively correlated with AI activity(P<0.05),starch content in seed kernel was positively correlated with starch content in green peel(P<0.05),and negatively correlated with AI activity in green peel(P<0.05).During fast-growing period,sucrose in walnut green peel was decomposed into glucose and fructose under the action of high-activity AI,which provided material and energy basis for cell division and morphological construction of walnut.During oil transformation period,sucrose accumulation in walnut green peel and kernel was the result of high-activity SS,SPS and low-activity AI and NI.