【摘要】 研究表明，在广东的自然条件下，优良稻种桂朝２号、七桂早等会发生过剩强光所造成的光抑制及光氧化伤害，但由于叶面积发展快，群体的光能截获能力较强，笔者确定这类品种属于适应低光强的生态型。而美国优良品种Ｌｅｍｏｎｔ、Ｂｅｌｅｍｏｎｔ等则光抑制及光氧化的伤害不明显，它们的叶片较厚，在强光下光合作用光能转化效率较高，但其叶面积发展速度较慢，笔者确定这类品种属于适应高光强的生态型。将这两种光强生态型的水稻组配成化杀杂种稻Ｌｅｍｏｎｔ／七桂早后，Ｆ１代杂种在反映群体光能截获能力及单叶光能转化效率的“整体光合能力”方面，较之父母本均有明显改进。其谷物产量的光能利用率在中国广州及美国阿肯色州均比父母本高８％～６２％。扩大的试验进一步证明：利用两种光强生态型的水稻组配成杂种稻后，Ｆ１代杂种均可比原亲本明显改进“整体光合能力”更多还原

【Abstract】 Photoinhibition(PI) and photooxidation(PO) damage caused by excessive strong light may be found in Guangdong elite rice varieties, such as Guichao 2, Qiguizao, etc. , under natural conditions in Guangdong province, China. These varieties are ecotypes adapted to low light intensity and characterized by quick development of leaf area and, therefore, stronger capacity of canopy light interception. On the contrary, the PI and PO damage to US elite rice varieties, such as Lemont, Bellemont, etc., is not significant. These varieties are ecotypes adapted to high light intensity and characterized by thicker leaf and higher photosynthetic efficiency of energy conversion under strong light, but the leaf area development of them is slow. By means of chemical hybridizing agent to make a hybrid rice "Lemont/Qiguizao", the integrated photosynthetic capacity of F 1 hybrid, in terms of both the light interception capacity in a canopy and the photosynthetic efficiency of energy conversion in individual leaves,was remarkably improved, compared with its parents. The solar energy use efficiency of Lemont/Qiguizao expressed in seed yield was about 8% ￣ 62% higher than its parents both in Guangzhou of China and in Arkansas of U.S.A. Expanded experiments further demonstrated that it is feasible to improve the integrated photosynthetic capacity of rice by making a hybrid rice from the two different light intensity ecotypes of rice.更多还原