花生硝酸还原酶与根瘤中固氮酶活性的研究

Studies on the Nitrate Reductase Activity (NRA) and the Nitrogenase Activity (NA) in the Nodules of Groundnut (A.hypogaea L.)

花生品种间根瘤量的变化有显著差异,但每克根瘤中固氮酶活性则差异不显著。固氮酶活性在全生育期出现两次高峰,分别在下针期和结荚期,而单株根瘤中固氮酶活性和单株根瘤量均在结荚期出现一次高峰。花生主茎复叶硝酸还原酶活性(NRA)在生育前期出现一次高峰,其活性的高低与品种耐肥性呈负相关。NRA 和根瘤中固氮酶活性有正相关关系,但不显著。NRA 与叶片NO_3^--N含量呈正相关。氮素种肥既抑制 NRA,也抑制根瘤的形成和根瘤中固氮酶的活性。NRA、根瘤中固氮酶活性都与籽粒粗蛋白含量呈正相关。

Studies on the nitrogenase activity(NA)and the nitrate reductase activity(NRA)in the nodules of groundnut revealed that although the number of nodules and noduleweight of different groundnut varieties were significantly different from each other,thedifferences among the NA of each gram of nodules of them were not significant.TheNA of the groundnut had two peaks during the entire growth period.one at thepegging stage and one at the pod-filling stage.But the NA of the nodules and thenodule weight of the individual plant had only one peak each at the pod-filling stage.The NRA of the compound leaves of the main stem had one peak in the earliergrowth period,and it was negatively correlated with the sensitiveness to fertilizers ofthe different varieties.It was also found that the NRA and NA of the nodules werepositively,but insignificantly correlated to each other.NRA was positively correlatedto the NO_3^--N content in the leaves.The application of N fertilizers as seed manurecould inhibite the NRA,the formation of nodules and the NA of the nodules.TheNRA and the NA of the nodules are positively correlated to the crude protein con-tent of the seed.