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期 刊 ：核农学报 2009年 23卷 6期 页码：1050-1053

关键词：镉；结缕草；胁迫；光合作用；叶绿素荧光；

Keywords:Cd, Zoysia japonica, stress, photosynthesis, chlorophyll fluorescence,

摘 要 ：用水培法研究了重金属Cd²⁺胁迫对结缕草叶片光合气体交换、叶绿素荧光参数、光能分配及叶绿素含量的影响。结果表明，Cd²⁺胁迫下，除胞间CO₂浓度（Ci）外，结缕草叶片净光合速率（Pn）、蒸腾速率(Tr)、气孔导度(Gs)均较对照降低，差异显著；最小初始荧光(F0)、最大荧光(Fm)、光下最大荧光(Fm′)、光下最小荧光(F0′)、稳态荧光(Fs)、最大量子产量(Fv/Fm)、实际量子产量(Fv′/Fm′)、实际光化学效率(ΦPSⅡ)、相对电子传递速率(rETR)、光化学猝灭系数(qp)等均较对照显著降低，而20d时处理叶片的非光化学猝灭系数(NPQ)较对照显著升高；在光能分配方面，除PSⅡ反应中心的过剩激发能C值无显著性变化，Cd²⁺胁迫显著降低了结缕草叶片PSⅡ光化学反应消耗的光能A值，显著提高了通过天线热耗散消耗的光能B值；尽管叶绿素与类胡萝卜素含量无显著变化，但30 d的Cd²⁺胁迫仍使二者含量降低。

Abstract:Effects of Cd2+ stress on photosynthetic, gas exchange parameters, chlorophyll fluorescence characteristics, excitation energy distribution and the content of photosynthetic pigment in the leaves of Zoysia japonica were studied. After the stress of Cd2+, net photosynthetic rate(Pn), transpiration rate(Tr) and stomata conductance(Gs) decreased significantly except of intercellular CO2 concentration(Ci). Minimum fluorescence(F0), maximum fluorescence(Fm), maximum fluorescence under light (Fm′), minimum fluorescence under light(F0′), steady-state fluorescence(Fs), maximal photochemical efficiency of PSⅡ(Fv/Fm), photochemical efficiency of PSⅡ in the light(Fv′/Fm′), the effective PSⅡ quantum yield(ΦPSⅡ), the relative electron transport rate(rETR) and photochemical quenching coefficient(qp) all decreased significantly compared with control, whereas nonphotochemical quenching coefficient (NPQ) increased significantly on 20th day after Cd2+ treatment. In the aspect of excitation energy distribution, A had decreased significantly, B had increased significantly, but the variety of C was not changed significant after Cd2+ treatment. Although under the Cd2+ stress the contents of chlorophyll and carotenoid did not vary significantly, but decreased compared with the control.

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