Abstract: The hybrid rice Le/Qi from crossing US rice Lemont with South China rice Qiguizao possesses improved integrated photosynthetic capacity both in light interception and light conversion efficiency, comparing with its parents, Therefore, give remarkably higher solar energy use efficiency of 53%～62% and 8%-15% than Lemont and Qiguizao, respectively, both in Arkansas of USA and in Guangzhou of China. Extended experiments with 12 hybrid combinations from US rice and South China rice demonstrated that nearly all the hybrids possessed remakably improved integrated photosynthetic capacity, quicker development of leaf area, as indicated by higher biomass production over US parents, and stronger capacity to scavenge toxic free radicals, therefore, giving higher efficiency of photosynthetic energy conversion under high light intensity over South China parents.

Key words: chemical hybridizing agents, hybrid rice, integrated photosynthetic capacity, light intensity ecotype, photoprotection

摘要： 由美国水稻Lemont和中国华南水稻七桂早所组配成的杂种稻Le/Qi，既具有较高的光能截获能力，又具有较高的光能转化效率，其整体光合能力和亲本相比，得到了明显的改进。不论是在美国阿肯色州，还是在中国广州，Le/Qi较之Lemont及七桂早，光能利用率分别提高了53%～62%及8%～15%，比美国亲本具有明显为高的产量，比中国亲本明显提高了品质，增加了经济产值。利用由美国水稻和中国华南水稻所组配成的12对杂种组合进行扩大试验的结果表明，几乎所有杂种都显示了整体光合能力的明显改进，比美国亲本具有明显为快的叶面积发展能力，表现在明显为高的生物学产量上；比中国华南亲本具有明显增强了清除有害自由基的能力，从而提高了在高光强下的光合作用光能转化效率。

关键词: 光强生态型, 杂种稻, 化学杂交剂, 整体光合能力, 光保护