Abstract: Rice sterile lines Gang 46A,776A and 2480A as the female parents were crossed with the improved restorer line Shuhui 881 containing maize phosphoenolpyruvate carboxylase gene(pepc) and the restorer line Shuhui 881(control). The dynamic changes of photosynthetic characteristics in leaves of the F₁ with pepc gene and controls were determined at the initial tillering, maximum tillering, booting, initial heading, heading, maturity stages and other six different periods after flag leaves completely expanded. The leaf PEPCase activities and net photosynthesis rate (Pn) of the three F₁s with pepc gene increased significantly as compared with the controls during the whole developmental stages, and the correlation coefficient (0.6081 ** ) between PEPCase activities and Pn in the three F₁s with pepc gene was significant. The leaf photosynthetic indexes of the three F₁s with pepc gene were obviously superior to the controls, being increased by 30.6%-59.7%, 29.8%-36.9% and 34.3%-40.0% in apparent quantum yield, light compensation point, carboxylation efficiency, respectively, and decreased by 23.5%-33.3% in CO₂ compensation point. The Pn of the three F₁ s with pepc gene at light saturated point and CO₂ saturated point was also higher than that of the controls. Furthermore, there was average 37.10% competitive advantage compared with the controls for the three F₁s with pepc gene on grain yield per plant. It indicated that the photosynthetic characteristics of the three F 1 s containing pepc gene have been improved to some extent as compared with their controls, which established physiological foundation for rice high production.

Key words: hybrid rice, phosphoenolpyruvate carboxylase gene, photosynthetic characteristic, high-photosynthetic efficiency breeding, heterosis

摘要： 用含pepc基因的改良蜀恢881与3个不育系冈46A、776A、2480A配组，同时以野生型亲本蜀恢881与上述3个不育系杂交得到的F1为对照，比较了3个含有pepc基因F1及其相应对照在分蘖初期、分蘖盛期、拔节期、始穗期、齐穗期、成熟期以及剑叶完全展开后不同时期的光合指标的动态变化。含有pepc基因的3个F1在不同生育期和剑叶展开后的磷酸烯醇式丙酮酸羧化酶（PEPCase）活力均显著高于各自对照，净光合速率也有所提高，分析表明PEPCase活力与净光合速率有极显著的相关性（0.6081**）。3个含有pepc基因F1的表观量子效率、光补偿点、羧化效率均高于对照，CO2补偿点较对照低，在光饱和点和CO2饱和点时的净光合速率也高于相应对照。在单株产量表现中，含pepc基因的F1较对照的平均增幅达37.10%。试验表明，杂交稻由于pepc基因的导入，光合特性得到了一定改善，奠定了水稻高产的生理基础。

关键词: 杂交稻, 磷酸烯醇式丙酮酸羧化酶基因, 光合特性, 高光效育种