土壤含水量对阿月浑子叶片净光合速率及叶绿素荧光参数的影响

 研究了土壤相对含水量对阿月浑子叶片叶绿素含量、净光合速率(Pn) 和荧光参数的影响。结果表明: 干旱胁迫降低了阿月浑子叶片Chl1a、Chl1b 含量和Pn , 增加了类胡萝卜素含量; 20 %供水处理降低了阿月浑子叶片的PS Ⅱ活性, 原初光能转化效率(Fv/ Fm) , 光化学猝灭系数(qP) , 非光化学猝灭系数(qN) 和PS Ⅱ电子传递量子产量(ΦPS Ⅱ) 。轻度干旱胁迫下, 气孔限制是Pn 降低的主要原因; 严重干旱胁迫下, 非气孔限制是Pn 降低的主要原因。干旱胁迫下阿月浑子叶片Pn 的下降是水分胁迫和强光胁迫双重作用的结果, PS Ⅱ电子传递量子产量(ΦPS Ⅱ) 降低是阿月浑子叶片Pn 下降的内在原因。

Effects of Soil Water Content Level on Net Photosynthetic Rate and Chlorophyll Fluorescence Parameters in Pistachio Leaves

Effects of relative soil water content on the changes of chlorophyll content , photosynthesis and the parameters of chlorophyll fluorescence in pistachio ( Pistacia vera L. ) leaves were investigated. The results were as follows : the content of Chl1a and Chl1b and the net photosynthetic rate in pistachio leaves were decreased while the content of carotenoid were enhanced by drought stress. The activity of PS Ⅱand the parameter of chlorophyll fluorescence in pistachio leaves such as conversion efficiency of primary light energy ( Fv/ Fm) of PS Ⅱ, the photochemical quenching coefficient (qP) , the Non2photochemical quenching coefficient (qN) and the quantum yield of PS Ⅱelectron transport (ΦPS Ⅱ) were decreased respectively when the relative soil water content is 20 %. The reasons of Pn decreased were stomatal and nonstomatal limitation respectively in light and severe drought stress condition. Under drought stress , It is a primary reason of net photosynthetic rate decreasing in pistachio leaves that the the quantum yield of PS Ⅱelectron transport (ΦPS Ⅱ) were reduced by soil drought and high irradiance.