以水稻品种献改优为材料分析了大田及人工光抑制条件下水稻叶片光抑制表现及谷胱甘肽-抗坏血酸循环系统(以下称谷-抗系统)运转状况。结果显示,在夏季典型晴天,午间水稻叶片光合作用表现出较明显的“午休”现象,阴天“午休”现象消失。表观量子效率分析表明“午休”现象与叶片光抑制有关。晴天水稻叶片谷-抗系统运转速率随日照强度增加而迅速加快,主要表现为谷胱甘肽总量以及谷胱甘肽还原酶活性的明显增加。而GSH/GSSG、抗坏血酸总量以及脱氢抗 In this study, the photosynthesis inhibition and glutathione-ascorbic acid (G-AS) circulatory system under the conditions of field and artificial photoperiod suppression were analyzed using rice varieties as the material for improvement. The results showed that during the typical sunny days in summer, photosynthesis in the leaves of rice showed a more obvious “lunch break” phenomenon and the phenomenon of “midday break” disappeared on cloudy days. Apparent quantum efficiency analysis showed that the phenomenon of “lunch break” was related to the inhibition of leaf photosynthesis. Sunny rice leaf valley-anti-system operating rate with the sun exposure intensity rapidly accelerated, mainly for the total glutathione and glutathione reductase activity increased significantly. While GSH / GSSG, total ascorbate, and dehydrogenation resistance