四个种源粉防己夏季光合特性比较

Comparison of Photosynthetic Characteristics of Four Geographical Provenances of Stephania tetrandra in Summer

以2年生粉防己为试材,对江西永丰、遂川、高安和乐平4个种源粉防己的光合生理特性及其与环境因子的相关性进行了研究。结果表明:4个种源粉防己的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)日变化均呈双峰曲线;胞间CO2浓度(Ci)日变化呈不规则的"W"型;4个种源之间光合特性存在差异;Pn日均值依次为:永丰种源>遂川种源>乐平种源>高安种源;除了Ci午后平均值比午前平均值略有增加之外,其它光合参数午后平均值均有较大幅度下降;影响粉防己Pn的主要指标有Tr、Gs、Ci;影响Tr的主要指标有Gs、Ci、光合有效辐射(PAR)。

Taking 2-year-old Stephania tetrandra as material, the photosynthetic characteristics of four provenances of Stephania tetrandra, which were from Yongfeng（YF）, Suichuan（SC）, Leping（LP）and Gaoan（GA）were studied. Li-6400 portable photosynthesis analyzer were used to measure the photosynthetic characteristics of the provenances in summer. The results showed that the net photosynthetic rate（Pn）, stomatal conductance（Gs）, and transpiration rate（Tr ）of the four provenances changed as bimodal peak curve;the intercellular C（）z （Ci）appeared to vary in a W-shaped curve. The photosynthetic characteristics between the four provenances were different;the order of average Pn of them taken as YF^SC~ LP^GA. The average values of Pn, LUE, Gs, Tr and WUE had decreased substantially in the afternoon while the average values of Ci increased slightly. The results of correlation analysis showed that Tr, Gs, Ci were the main influencing factors on Pn; and that Tr closely related with Gs,Ci, PAR.