Abstract: Two newly bred hybrid rice combinations, super high-yielding rice Liangyoupeijiu (Pei′ai 64S×9311) and Pei′ai 64S/E32 were used to investigate the photosynthetic characteristics at high temperature in comparison with hybrid rice (Shanyou) 63. High temperature caused a decreasing photosynthetic efficiency and aggravated photoinhibition. The optimum temperatures of photosynthetic electron transportation and photosynthetic CO₂ fixation were about 28℃ and 35-40℃, respectively. Linear electron transportation was more sensitive to high temperature than the photochemical process. The mechanism of high temperature adaptation in super high yielding rice might involve that carotenoid increase more quickly in super high-yielding rice and act as a better antioxidant system to reduce the active oxygen production and avoid the photosynthesis machinery hurting, and super hybrid rice has a higher efficiency of xanthophylls cycle to dissipate excess excitation energy, and has a more stable photosynthetic function, higher photosynthetic efficiency and more heat stable protein content.

Key words: super high yielding hybrid rice, high temperature, stress, photosynthesis

摘要： 以汕优63为对照，研究了新育成的两个超级杂交水稻组合培矮64S/E32和两优培九的高温耐受特性。结果表明高温引起了光合效率降低，加重了光合光抑制。光化学、光合电子传递最适温度在28℃左右，光合碳同化的最适温度在35～40℃。高温下通过PSⅡ线性电子传递的能力几乎丧失（下降96.7%～100%），而PSⅡ光化学效率下降较少（8.8%～210%）,暗示PSⅡ光合线性电子传递过程比光化学能转化对高温更敏感。超级杂交稻比对照汕优63更耐高温，其机理可能如下：一是因为超级稻在高温时有更迅速的类胡萝卜素积累，增加其抗氧化能力，减少了因过剩激发能积累引起活性氧产生、积累并伤害光合细胞；二是因为超级稻高温下有高效的叶黄素循环热耗散途径可以耗散过量的激发能； 三是因为超级稻在高温下有稳定的光合功能和较强的光合效率，较高的热稳定蛋白含量。

关键词: 超级杂交水稻, 高温, 逆境, 光合作用