Abstract: [Objective] Through the analysis of seasonal dynamics of crude fat content, crude protein content and soluble sugar content and the activities of enzymes related with sugar metabolism in the kernel of walnut varieties with different oil contents, this study aimed at understanding the relationship between oil content and nutrition metabolism and having a deep insight into the metabolism of oil synthesis in walnut kernel.[Method]Walnut varieties with high oil content (Juglans.regia'Xinfeng'and J.regia'Wen185') and walnut varieties with low oil content (J.regia'Xinzaofeng', J.regia'Zha 343'and J.regia'Xinxin2') were used as the experimental materials.In the developmental process of walnut fruit, the walnut kernels with different oil contents were sampled to measure the content of crude fat, crude protein and soluble sugar, and the activities of enzymes related with sugar metabolism.[Result]120-150 days after flowering (DAF), there was a significant difference in crude fat content in kernel among different walnut varieties (P<0.05).60 DAF, the soluble sugar content in walnut varieties with high oil content was significantly higher than that in walnut varieties with low oil content (P<0.05).120-150 DAF, the soluble sugar content in walnut varieties with high oil content was significantly lower than that in walnut varieties with low oil content (P<0.05).There was no regular difference in crude protein content in kernel between walnut varieties with different oil content.30-60 DAF, the activities of AI and NI in the walnut varieties with high oil content were significantly lower than those in the walnut varieties with lower oil content (P<0.05).120-150 DAF, the activity of SPS in walnut varieties with high oil content was significantly higher than that in low oil content varieties (P<0.05).But there was no regular difference in the activity of SS in kernel between walnut varieties with different oil contents.[Conclusion]The oil synthesis in the walnut kernel is neither dependent on the early accumulation of soluble sugar in the kernel nor dependent on protein metabolism, but the low activities of NI and AI in kernel during the early stage of walnut fruit development and the high activities of SPS during later stage are conducive to the oil synthesis.

摘要： [目的]通过分析不同含油率核桃(Juglans regia)品种果实生长发育过程中其种仁粗脂肪、粗蛋白和可溶性总糖含量随时节推移的动态变化,以及与糖代谢相关酶活性的变化,了解其与种仁含油率之间的关系,加深对核桃种仁油脂合成代谢的认识.[方法]以种仁高含油率核桃品种新丰(J.regia 'Xinfeng')、温185(J.regia 'Wen185')和低含油率核桃品种新早丰(J.regia 'Xinzaofeng')、扎343(J.regia 'Zha 343')、新新2号(J.regia 'Xinxin2')为研究对象,采样测定果实不同生长发育时节其种仁粗脂肪、粗蛋白和可溶性总糖含量,以及种仁中中性转化酶(NI)、酸性转化酶(AI)、蔗糖合成酶(SS)和蔗糖磷酸合成酶(SPS)的活性.[结果]花后120~150 d,种仁粗脂肪含量在供试的核桃品种之间存在显著性差异(P<0.05);花后60 d,高含油率品种其种仁可溶性总糖含量显著高于低含油率品种(P<0.05),花后120~150 d,显著低于低含油率品种(P<0.05);种仁粗蛋白含量在高、低含油率品种之间无规律性差异;花后30~60 d,高含油率品种其种仁中AI和NI活性显著低于低含油率品种(P<0.05);花后120~150 d,高含油率品种其种仁中SPS活性显著高于低含油率品种(P<0.05);种仁中SS活性在高、低含油率品种之间无规律性差异.[结论]核桃种仁油脂合成既不依赖于种仁前期积累的糖类物质,也不依赖于种仁中蛋白质的合成代谢,但果实生长发育前期种仁中低活性的AI、NI和后期种仁中高活性的SPS有利于油脂的合成.