夜间亚低温处理及其恢复对番茄叶片光抑制的影响

 为探讨夜间亚低温对番茄叶片光合作用影响的生理机制，研究了9 ℃夜间亚低温处理及恢复条件下番茄叶片净光合速率(Pn)和叶绿素荧光参数的变化。结果表明:夜间9 ℃亚低温处理3 d以上，叶片Pn、PSII最大光化学量子产量(Fv/Fm)、PSII潜在的活性(Fv/Fo)、实际光化学量子效率(фPSII)、PSII的电子传递速率（ETR）、光化学猝灭系数（qP）均下降，初时荧光(Fo)、PSII的还原状态(1-qP)、非光化学猝灭系数(NpQ)均提高；但夜间9 ℃亚低温处理9 d以内，除了NpQ在9 d恢复性处理后仍未恢复到对照水平外，其它叶绿素荧光参数均恢复到对照水平。上述结果说明：9 ℃夜间亚低温处理3 d就明显引起番茄成熟叶片光合作用的光抑制，而9 d以下的夜间9 ℃亚低温处理对PSII的影响是可逆的，即短期9 ℃夜间亚低温所引起的番茄叶片光合作用的光抑制现象是可以恢复的。

Effect of Sub-low Night Temperature Treatment and Recovery on the Photoinhibition of Tomato Leaves

In order to discuss the physiological mechanism of effect of sub-low night temperature on photosynthesis in tomato leaves, the change of net photosynthetic rate（Pn）and chlorophyⅡfluorescence paramerers of tomato leaves under the condition of sub-low night temperature at 9 ℃for 3 to 9 days and then recover for 9 days at optional temperature were studied. Treated with sub-low night temperature at 9 ℃ for more than 3 days, it was shown that the net photosynthetic rate (Pn), the maximum photochemical efficiency(Fv/Fm), potential activities of PSII(Fv/Fo), the actual photochemical efficiency of PSⅡreaction center (ΦPSⅡ), rate of electronic transmission of photosynthesis (ETR), photochemical quenching coefficient (qP) of leaves deceased, while intrisic fluorescenc of (Fo), the relative reduction state of PSⅡ(1-qP) and the non-photochemical quenching coefficient (NpQ) increased. But when tomato leaves were treated with sub-low nigth temperature for less than 9 days and then recovered for 9 days,most chlorophyll fluorescence parameters could come back to CK, except NpQ. These results showed that the phenomenon of photoinhibition of photosynthesis in tomato mature leaves has been induced obviously after treated with sub-low night temperature at 9 ℃ for 3 days, and that it was reversible that the effect of treatment of sub-low night temperature at 9 ℃for less than 9 days on PSⅡ. Namely, the phenomenon of photoinhibition of photosynthesis in tomato leaves induced by short-term 9 ℃ sub-low night temperature could recover.