南方3种果树叶片蛋白质和硝态氮动态观察

目的]研究果树叶片贮藏蛋白质的动态变化规律和氮素积累与降解的调控机理,探讨硝态氮与蛋白质代谢的相关性,为果树的合理施肥和科学管理提供依据.方法]以南方常绿果树芒果、龙眼和荔枝的秋梢叶片为材料,采用考马斯亮蓝染色法和水杨酸法分别测定其春季期间的总蛋白质含量和硝态氮含量.结果]芒果、龙眼、荔枝3种南方果树的秋梢叶片中总蛋白质含量均呈前期下降后期上升的“V”字型变化趋势,但平均含量差异较大,龙眼含量最高,为18.03 mg/g,芒果为11.57 mg/g,而荔枝仅有2.53 mg/g;硝态氮含量变化规律不明显,龙眼和荔枝叶片中的硝态氮含量在各阶段都呈现大幅上升的变化趋势,而芒果为先下降后上升.结论]硝态氮与蛋白质代谢的相关性不显著,叶片中的营养贮藏蛋白质可能是果树早春生长的重要氮源,叶片中蛋白质含量的变动变化可作为果树合理施肥的一个重要指标,但不同树种蛋白质含量水平存在差异.

Dynamic variation of protein and nitrate nitrogen in leaves of three types of southern fruit trees

【Objective】Dynamic variation of protein and mechanism of nitrogen accumulation and degradation in southern fruit tress were studied in the experiment，and correlation analysis was conducted between nitrate nitrogen and protein metabolism to provide references for rational fertilization and scientific management of fruit trees. 【Method】Using the leaves of autumn shoots from three evergreen fruit trees: mango， longan and litchi as test material， total protein content and nitrate-N content in leaves during spring and summer were determined by Commassie Brilliant Blue Staining and Salicylic Acid methods， resepctively. 【Result】The results showed that the total protein content in the leaves of mango， longan and litchi all decreased firstly and increased afterwards with“V”type variation， the average protein content in leaves of three fruit trees followed the trend: longan （18.03 mg/g）＞mango（11.57 mg/g）＞litchi （2.53 mg/g）. The nitrate nitrogen content in leaves of litchi and mango showed stable increasing trend， while that of mango decreased firstly and increased afterwards. 【Conclusion】There was no significant correlation between nitrate nitrogen and protein metabolism in leaves of southern fruit trees. The storage protein in leaves may be a key nitrogen source for fruit tree growth in early spring， its content variation could be reckoned as an importatn indicator for reasonable fertilization.