含氮化合物是树木重要的组成物质,而硝酸还原酶(以下称NR)是植物硝酸盐同化过程中的一个关键酶和限速酶,它在作物生长发育过程中具有重要作用,可作为作物育种和营养诊断的生化指标。NR的测定方法有两种,即体外测定法和体内测定法,这两种测定方法几经改进,在作物上亦已广泛应用。体外测定法比较精确、稳定,适合多样品一次采样分批测定,但测定过程需要零下低温,操作较为严 Nitrogen compounds are important components of trees. Nitrate reductase (hereinafter NR) is a key enzyme and rate-limiting enzyme in plant nitrate assimilation. It plays an important role in crop growth and development and can be used as crop breeding And nutrition diagnosis of biochemical indicators. There are two methods for the determination of NR, in vitro and in vivo, which have been improved several times and are also widely used in crops. In vitro assay is more accurate and stable, suitable for multiple sample batch determination of a sample, but the determination of the process requires zero low temperature, the operation is more stringent