CO2浓度增高对三裂叶蟛蜞菊光合生理特性的影响

在人工控制CO2浓度梯度条件下,测量了喜阴多年生草本植物三裂叶蟛蜞菊1月和3月的光合速率(Pn)、蒸腾速率(Tr)、胞间CO2浓度(Ci)、气孔导度(Gs)和叶面饱和蒸气压亏缺(Vpdl)。结果表明:CO2浓度升高对三裂叶蟛蜞菊的光合生理特性影响较大,当CO2浓度由0升高到1900μmol·mol1的过程中,Pn增加很快,其值在1.53～11.3μmol·m2·s1之间;水分利用率(WUE:光合与蒸腾之比)随CO2浓度的升高也在增大,当CO2浓度为1900μmol·mol1时,1月份的WUE是18.248μmol·mmol1,3月份的只有8.794μmol·mmol1,高水分利用效率与其对干旱的适应性密切相关。

Effects of CO2 concentrations increasing on photosynthetic physiological characteristics of Wedelia trlobata

In order to study influence of CO2 enhance on photosynthetic physiological characters of Wedelia trlobata L.,photosynthesis rate(Pn),transpiration rate(Tr),intercellular CO2 concentrations(Ci),stomatal conductance(Gs)and vapor deficit at the leaf surface (Vpdl)were measured on individuals of W.trlobata with the effective of CO2concentrations increased from 0 to 1 900 μmol·mol 1 . Results were summarized as followed:Pn,Ci and WUE all increased with the increasing of CO2 concentrations. The Gs,Tr in January at first increased with the increasing of CO2 concentrations,but later decreased as CO2 concentrations exceed 1 000 μmol·mol 1 . The Gs,Tr in March reduced with the increasing of CO2 concentrations. The value of WUE is also increased with the increasing of CO2 concentrations,but there is a difference between January and March at 1 900 μmol·mol 1 . There may be more correlation between WUE and dry ability of W.trlobata .