用低氮 (LN)、中氮 (MN)、高氮 (HN)盆栽土培的杂交水稻汕优 63为材料 ,测定其剑叶的光合速率、 Ru BP羧化酶含量及活性、可溶性蛋白和叶绿素含量的变化。结果表明 :随着氮水平的提高 ,叶面积增大 ,气孔密度减少 ,Ru BP羧化酶活性和光合速率增加。随着叶龄的增加 ,三个不同氮水平的叶片中 Ru BP羧化酶蛋白下降均先于可溶性蛋白的下降 ;HN组的光合速率下降幅度小于 LN组和MN组 ;HN组的 Ru BP羧化酶较高活性的持续期长于 L N组和 MN组。氮素对杂交水稻的光合速率和光合功能期具有调节作用 The hybrid rice Shanyou 63 with low nitrogen (LN), medium nitrogen (MN) and high nitrogen (HN) was used as material to measure the photosynthetic rate, Ru BP carboxylase content and activity, soluble protein and Changes in chlorophyll content. The results showed that with the increase of nitrogen level, the leaf area increased, the stomatal density decreased, and the activity of Ru BP carboxylase and photosynthetic rate increased. With the increase of leaf age, the decrease of Ru BP carboxylase protein in leaves of three different nitrogen levels was earlier than that of soluble protein; the decrease rate of photosynthetic rate in HN group was smaller than LN group and MN group; The duration of higher activity of the enzyme was longer than that of the LN and MN groups. Nitrogen has a regulatory effect on the photosynthetic rate and photosynthetic function of hybrid rice