Abstract: It was demonstrated that photoinhibition occnred in rice under natural high light intensity, showing decrease of photosynthesis, chlorophyll content and quantum yield. The damage of photoinhibition was remarkably light in US rice Bellemont and Lemont, but severe in Chinese rice Gui-Chao 9. Morphologically, the leaf thickness of US rice could increase as the light intensity increased, but couldn't for Gui-Chao 2. Gui-Chao 2 could delay leaf senescence under long term shading condition, therefore, it could keep relative higher photosynthesis than that of US rice. Experiment also showed nitrogen fertilizer could reduce the damage of photoinhibition and improve the adaptability of rice to high light intensity. It was tentatively proposed that there would be two light intensity ecotypes in rice and discussed the possibility of reducing photomhibition and increasing solar energy utilization through rational breeding and cultivation.

Key words: Photoinhibition, Rice, Light intensity ecotype

摘要： 试验证实了水稻在自然强光条件下存在光抑制现象,表现在强光下净光合速率、叶绿素含量及量子产量的下降。但美国品种Bellemont和Lemont在强光下的光抑制程度明显比中国品种桂朝2号轻。在形态学上,美国品种能随光强度的增强而增加叶片厚度,而桂朝2号则不能。桂朝2号在长期遮阴条件下,叶片衰老延迟,从而能比美国品种保持相对较高的光合能力。试验还表明施用氮肥可减轻光抑制的伤害程度及增强对强光的适应性。文中提出了水稻中存在两种光强生态型的初步看法,並讨论了通过育种栽培途径减轻水稻光抑制提高光能利用率的可能性。

关键词: 光抑制现象, 水稻, 光强生态型