水分胁迫对不同甘蔗品种叶绿素a荧光动力学的影响

利用 OS5- FL调制式叶绿素荧光分析仪研究水分胁迫对不同甘蔗品种叶片叶绿素 a荧光动力学的影响 .结果表明 :水分胁迫下蔗叶可变荧光产量 (Fv值 )下降 ,T1/ 2 减少 ,蔗叶光系统 (PS )原初光能转换效率(Fv/ Fm)和 PS 潜在活性 (Fv/ Fo)降低 ;蔗叶可变荧光衰减能力 (Δ Fv)下降 ,光合作用潜在活力降低 ,影响光合电子传递和 CO2 同化的正常进行 ,表现为可变荧光淬灭速率 (Δ Fv/ Fo)减慢 ,荧光下降比值 (Δ Fv/ Ft值 )变小 ,光合量子产额 (Yield)减少 .同时还讨论了水分胁迫对蔗叶光合作用影响的机制

Effects of water stress on the chlorophyll a fluorescence induction kinetics of sugarcane genotypes

The effects of water stress on the chlorophyll a fluorescence induction kinetics of sugarcane genotypes were studied by using OS5 FL modulated chlorophyll fluorometer. The results indicated that chlorophyll a fluorescence induction kinetic curves of sugarcane were changed obviously during water stress. The decrease of variable fluorescence yield (Fv values), the time in ms from the point Fo to the point on the rising curve corresponding to 1/2 Fv (T 1/2 ), the ratio of the variable to maximal fluorescence (Fv/Fm), the ratio of the variable to minimal fluorescence (Fv/Fo), ΔFv values, variable fluorescence quenching rate (ΔFv/Fo), Rfd values and photochemical quantum yield (Yield =Fds/Fms) under water stress suggested that the primary light energy conversion of PSⅡ, the potential activities of PSⅡ, the potential photosynthetic activities, photosynthetic electron transport and the carbon assimilation had been inhibited. Meanwhile, the responsive mechanism of photosynthesis in sugarcane leaves to water stress were discussed.