水分胁迫对小麦旗叶叶绿素a荧光参数和光合速率的影响

Effect of water stress on the photosynthesis of flag leaf of winter wheat

利用 OS- 30型叶绿素荧光分析仪研究水分胁迫对小麦旗叶叶绿素 a荧光动力学参数的影响。结果表明 ,水分胁迫下旗叶的 T1 /2 值减少 ,旗叶光系统 (PS )原初光能转化效率 (Fv/ Fm)和潜在活性 (Fv/ F0 )降低。光合作用的潜在活力降低 ,影响了光合电子的传递和 CO2 同化的正常进行 ,表现在可变荧光淬灭速率 (Δ Fv/ F0 )减慢 ,可变荧光下降比值 (Rfd=Δ Fv/ Ft)减小 ,进而影响冬小麦旗叶的光合速率。

Effect of water stress on the chlorophyll a fluorescence parameters of flag leaf of the wheat was studied by using OS 30 chlorophyll fluorometer. The result indicated that the chlorophyll a fluorescence parameters of flag leaf were changed obviously under water stress. The decrease of the time in ms from the opint F 0 to the point of 1/2 F v (T 1/2 ), the ratio of the variable to maximal fluorescence (F v/F m), the ratio of the variable to minimal fluorescence (F v/F 0), variable fluorescence quenching rate (ΔF v/F 0) and Rfd (ΔF v/F t) values under water stress suggested the primary light energy conversion of PSⅡ, the potential activities of PSⅡ, the potential photosynthetic activities and photosynthetic electron transport had been inhibited. Meanwhile effect of water stress on leaf water potential was discussed.