关键词: 南岭黄檀, 固氮酶, 吸氢酶

Abstract: Nitrogenase and hydrogenase activities were determined and the relation-ship between them was investigated in the nodules of Dalbergia balansae under different environmental conditions,Hydrogen uptake activity was found in the nodules of D. balansae. In the presence of exogenous hydrogen,nitrogenase activity in nodules increased markedly,suggesting that hydrogenase played an important role in increasing the efficiency of nitrogen-fixation in symbiotic system. Low level of nitrate did not influence the nitrogenase and hydrogenase activities in the nodules,however,ammonium showed a negative effect on the expression of both enzyme activities. The optimum temperature for both nitrogenase and hydrogenase activities was about 25℃. Minor soil water deficit did not affect the acetylene-reducing activity,but serious soil drought markedly reduced the activities of nitrogen-fixation and hydrogen uptake. Shading reduced both nitrogenase and hydrogenase activities of nodules.

Key words: Dalbergia balansae, Nitrogenase, Hydrogenase