Abstract: With nearisogenic line fgl (faded green leaf) and Zhefu 802(recurrent parent, green leaf) as materials, the leaf senescence course of different leaf color rice was compared, and the effect of light intensity on leaf senescence was studied. Under natural light intensity, fgl rice lines senesced more slowly than normal green leaf rice Zhefu 802. The chlorophyll content, leaf area index and photosynthetic rate of fgl lines decreased more slowly than those of Zhefu 802, especially at the initial grainfilling stage and late grainfilling stage. Moreover, superoxide dismutase (SOD) activity of flag leaves in fgl lines decreased more slowly, while malonaldehyde (MDA) content increased faster compared to Zhefu 802 after flowering. Low irradiance delayed rice leaf senescence. The chlorophyll content, photosynthetic rate, intercellular CO2 concentration, stomatal conductance of Zhefu 802 increased significantly at 85% of natural light intensity compared to natural light intensity, while the photosynthetic rate of fgl was stable and insensitive to light intensity changes.

Key words: rice, leaf color, senescence, light intensity, superoxide dismutase activity, malonaldehyde content

摘要： 以淡绿叶水稻近等基因系fgl及其正常叶色的轮回亲本浙辐 802为材料，比较了不同叶色水稻抽穗后叶片的衰老进程，并在水稻抽穗后施以不同强度的光照，研究水稻生育后期光照强度对不同叶色水稻叶片衰老的影响。在自然光强下，淡绿叶水稻fgl的衰老慢于轮回亲本浙辐 802，fgl的叶绿素、叶面积指数和净光合速率的下降速率均慢于浙辐 802，特别是在灌浆前期和后期；开花后浙辐 802的SOD活性下降和MDA含量的上升均快于fgl。15%的遮光处理有利于提高浙辐 802的气体交换特性和光合性能，提高SOD活性，降低MDA含量；而浅叶色的fgl的光合速率较稳定，受光强的影响较小。

关键词: 水稻, 叶色, 衰老, 光强, 超氧化物歧化酶活性, 丙二醛含量