Abstract: Effect of pH on photosynthetic rate of leaf, electron transfer activity of photosystem, absorption spectrum, fluorescence emission spectrum at room temperature, and polypeptide compositions of rice seedlings thylakiod membrane were observed. Results showed that under pH 4.0 and pH 8.0, the electron transfer activity of PSⅠand PSⅡ were inhibited and the inhibition to PSⅡwas stronger than that to PSⅠ. The fluorescence emission spectrum of thylakiod membrane was reduced, whereas the absorption spectrum was strengthened at room temperature. The polypeptide compositions were not changed. pH 6.0 is the fittest to rice seedlings growth.

Key words: hybrid rice, seedlings, pH, stress, thylakiod membrane, photosynthetic characteristics

摘要： 模拟土壤pH值对杂交稻两优培九幼苗叶片光合速率、类囊体膜的光合电子传递活性、室温吸收光谱、室温荧光发射光谱以及多肽组分影响的研究结果表明,当土壤pH值小于5.0或大于7.0时，叶片光合速率、PSⅠ和PSⅡ的电子传递活性以及类囊体膜室温荧光发射峰值均有不同程度的降低，其中尤以pH 4.0试验组的降低幅度最为显著；pH 4.0与pH 8.0两个试验组使类囊体膜的室温吸收光谱峰值得到增强，但未使多肽组分发生明显改变。研究证明，与酸性环境相比，水稻幼苗对碱性环境的耐受能力更强，其生长的最适土壤pH值为6.0。

关键词: 杂交水稻, 幼苗, pH值, 胁迫, 类囊体膜, 光合特性