【摘要】 群体叶片截获光能能力的叶面积指数（ＬＡＩ）的发展和单个叶片光能转化效率的最大光合速率（Ｐｍ ａｘ），是提高水稻光能利用效率的两大关键性的指标．利用适应低光强生态型的、ＬＡＩ发展快的广东优良品种“七桂早”，与适应高光强生态型的、Ｐｍ ａｘ 高的美国优良品种“Ｌｅｍ ｏｎｔ”为亲本，利用化学杂交剂组配成化杀杂种稻Ｌｅ／七，较好地解决了ＬＡＩ与Ｐｍａｘ的矛盾．Ｌｅ／七既保持了父本“七桂早”早期ＬＡＩ发展快的优点，又兼具有母本“Ｌｅｍ ｏｎｔ”Ｐｍａｘ较高、适应高光强的优点．杂种Ｌｅ／七在中午强光下光合作用“午睡”现象不明显，尤其是当广东出现造成水稻光氧化伤害的气象条件时，Ｌｅ／七的光氧化伤害很轻或无，比“七桂早”明显提高了对高光强的光能利用效率．对杂种Ｌｅ／七在人工气候箱不同控光控温条件下进行的生长分析，及在平原、丘陵及山区的试种，均表明其光合生产力和光合适应性比亲本有明显的提高和改进．研究表明∶利用美国适高光强的优良品种，通过组配成化杀杂种稻的途径，是改良广东水稻品种对高光强的光合适应性，提高光合生产力和经济效益的一条快速而有效的育种途径．更多还原

【Abstract】 The leaf area index (LAI) development, which related to the capacity of light interception, and the maximum leaf photosynthetic rate (P max ), which related to the efficiency of light energy conversion, are two key photosynthetic traits to increase the utilization efficiency of solar energy. Using the Guangdong rice “Qiguizao”, which belongs to low light adaptable ecotype and characterized by quick developing LAI, and the US rice “Lemont”, which belongs to high light adaptable ecotype and characterized by higher light saturation point of photosynthesis, as parents to make a hybrid (Le/Qi) by means of chemical hybridizing agent, the authors successfully solved the contradiction between LAI and P max . The hybrid Le/Qi not only showed quick developing LAI, but also higher P max , less or no midday depression of photosynthesis and less or no photooxidation under high light induced conditions. The photosynthetic productivity and adaptability of Le/Qi were increased over 20% and improved a lot according to the growth analysis under different light and temperature conditions in growth chambers and field trials in flatlands, hilly land or mountain area. This study indicated that utilization of high light adaptable US elite rice as parent to make a hybrid with Guangdong low light adaptable local elite rice by means of chemical hybridizing agent is an effective and quick breeding approach to improve the adaptability of Guangdong rice to high light and to increase the photosynthetic productivity in turn the economic income.更多还原