Abstract:

Effects of photoinhibition and its recovery on photosynthetic functions of winter wheat ( Triticum aestivum L.) under salt stress were studied. The results showed that several parameters associated with PSⅡ functions, e.g. Fv/Fo 、 Fv/Fm and qP were not influenced by lower salt concentration (200 mmol/L NaCl) while CO2 assimilation rate decreased significantly. When exposed to higher salt concentration (400 mmol/L NaCl), PSⅡ functions were significantly inhibited which led to the decrease of carbon assimilation. These results suggest that different concentrations of salt stress affected photosynthesis by different modes. Salt stress made photosynthesis more sensitive to strong light and led to more serious photoinhibition. Under lower concentration of salt stress, the QB-non-reductive PSⅡ reaction centers formed at the beginning of photoinhibition could be effectively used to compose active PSⅡ reaction center (RC) and repair the reversible inactivated PSⅡ RC. Under higher concentration of salt stress, PSⅡ reaction centers were seriously damaged during photoinhibition, the QB-non-reductive PSⅡ RC could only be partly effective at the early time of photoinhibition, thus led to the accumulation of QB-non-reductive PSⅡ RC in the course of restoration under dim light.

在盐胁迫下光抑制及其恢复进程对冬小麦光合功能的影响
朱新广 王强 张其德* 卢从明 匡廷云
（中国科学院植物研究所光合作用基础研究开放实验室，北京100093）

Key words: winter wheat, salt stress, photoinhibition