氮素营养水平对春小麦叶片光合、光呼吸及硝酸还原的影响

春小麦叶片的光呼吸强度、乙醇酸氧化酶及硝酸还原酶的活力和叶绿素含量均随硝态氮供应量的增加而增高。光合强度在低氮至正常氮范围内(1/4氮—1氮)随氮量的增加而增高,但在高氮范围内(2氮—4氮)则随氮量增加略有所下降。上述各项生理指标也随氨态氮的增加有所提高,但变化的幅度不如硝态氮处理的明显。在供氮的植株中,测不出硝酸还原酶的活力。用光呼吸抑制剂亚硫酸氢钠等真空渗入叶片而使光呼吸受到抑制时,发现硝酸还原也受到抑制。这说明光呼吸与硝酸还原有着密切的关系。

Effect of Nitrogen Nutrition Level on Photosynthesis, Light Respiration and Nitrate Reduction of Spring Wheat Leaves

Light respiration, activities of ethanol acid oxidase and nitrate reductase, andnitrate reductase, and chlorophyll content of spring wheat leaves increases assupply amount of nitrate nitrogen increases. Photosynthesis intensity increases asnitrogen amount increases in low and normal nitrogen extent (1/4 nitrogen--1nitrogen), but the intensity decreases slightly as nitrogen amount increases inhigh nitrogen extent (2 nitrogen--4 nitrogen). The above physiological criteriaincreases as amino nitrogen increases, but the change is less obvious than thechange caused by nitrate nitrogen. When light respiration inhibitors, such as sulphurous acid hydrogen sodium,permeat the leaves of spring wheat under vacuum condition, the light respirationls inhibited, and the nitrate reduction is also inhibited at the same time, Theresult shows that a close relation exists between light respiration and nitrate re-duction.