施氮水平对不同花生品种氮代谢及相关酶活性的影响

Effects of Nitrogen Application Rates on Nitrogen Metabolism and Related Enzyme Activities of Two Different Peanut Cultivars

【目的】花生籽仁蛋白质含量较高,研究花生不同器官中氮代谢酶活性在施氮水平和品种间的差异及其与籽仁蛋白质含量间的关系,阐述花生氮素代谢的生理特性。【方法】选用生产中普栽品种花育22号和白沙1016,设置4个氮素水平,测定两品种不同生育期各器官中主要含氮物质(可溶性蛋白质(Pro)、游离氨基酸(AA))含量及主要氮代谢酶(硝酸还原酶(NRase)、谷氨酰胺合成酶(GS)和谷氨酸脱氢酶(GDH))活性。【结果】两品种各器官Pro、AA、NRase、GS、GDH活性的变化态势大致相同,但其含量的高低因品种和施氮量不同而变化,各器官中各指标含量均以白沙1016较高;适当提高氮素水平可增加各器官中可溶性蛋白质和游离氨基酸的含量和主要氮代谢酶活性;氮素水平过高虽能提高硝酸还原酶和籽仁蛋白质含量,但谷氨酰胺合成酶(GS)和谷氨酸脱氢酶(GDH)的活性下降;各营养器官中可溶性蛋白质含量与GS和GDH活性间的相关关系不明显,但与其相应器官中的NRase活性表现显著或极显著相关,荚果中Pro与AA和NRase间、GS和GDH、NRase与游离氨基酸间均呈极显著的相关关系。【结论】施氮量和品种差异对花生各器官中游离氨基酸和可溶性蛋白质含量及氮代谢酶活性有影响,白沙1016对高量氮肥较敏感,花育22号则较适应高氮;增施氮肥通过改变氮素代谢的生理特性改善花生品质。

【Objective】This experiment was conducted to study the characters of nitrogen metabolism and provide a basis for high yield and quality of peanut,by determining the effects of nitrogen level and cultivars on nitrogen metabolism related enzymes,and analyzing their relationship with protein content in peanut kernel.【Method】 The effects of four nitrogen levels and two cultivars,Huayu 22（High yield big peanut） and Baisha 1016（Small peanut）,on soluble protein content（Pro）,free amino acid content（AA）,nitrate reductase（NR）,glutamine synthetase（GS） and glutamate dehydrogenase（GDH） in different organs of peanut at different growth stages were determined.【Result】The results showed that the change trends of Pro,AA,NR,GS,GDH in different organs of the two types of peanut cultivars were similar.But the values of Baisha 1016 were higher than those of Huayu 22 in different organs.With the increase of nitrogen,Pro and AA were increased,and the activities of NR,GS and GDH were also increased.When excessive nitrogen was used,NR and Pro were increased,while the activities of GS and GDH were decreased.In each organ,Pro had no obvious relationship with GS and GDH activities,but was significantly related to NR activity.And the correlations between Pro and AA,Pro and NR,GS and GDH,and NR and AA,were all significant.【Conclusion】 There are significant effects of nitrogen level and cultivars on AA,Pro and the nitrogen metabolism related enzymes in different organs.Baisha 1016 is more sensitivity to high nitrogen level than Huayu22.Application of more nitrogen could improve the quality of peanut by the changes of nitrogen metabolism.