水分胁迫及复水对达乌里胡枝子光合特性的影响

以来自山西的6个生态型达乌里胡枝子(Lespedeza davurica(Laxm.)Schindl)为材料,通过测定干旱胁迫和复水后植物叶片净光合速率(P_n)、蒸腾速率(T_r)、气孔导度(G_s)、水分利用效率(WUE)、胞间CO₂浓度(C_i)和叶绿素含量等指标,研究了不同生态型达乌里胡枝子在水分胁迫下和复水后光合特性与抗旱性的关系。结果表明:随干旱胁迫程度加剧,6个生态型达乌里胡枝子P_n,T_r和G_s值均有较大幅度的降低,水分利用效率呈下降趋势,光合作用减弱。其中沁水和沁源生态型的P_n下降速度快、幅度大、抗旱性差,阳泉和交口生态型的P_n下降速度慢、幅度小、抗旱性强;复水后抗旱性强的生态型恢复至正常状态的能力强,其WUE比抗旱性差的生态型高。抗旱性由强到弱的顺序是:阳泉>交口>太谷>静乐>沁源>沁水。

Effects of Water Stress and Rehydration on Photosynthetic Characteristics of Lespedeza davurica (Laxm.) Schindl

Lespedeza davurica (Laxm.) Schindl is a perennial leguminous semi-shrub legume acting as a community dominant species of the Loess Plateau with drought,cold and barren resistance.The net photosynthetic rate of leaves (P_n),transpiration rate (T_r),stomata conductance (G_s),chlorophyll content,water using efficiency and inter cellular CO₂ concentration were studied to explore the relationships of photosynthetic characteristics and drought resistance under six different ecotypes of Shanxi Province.Results showed that P_n,T_r and G_s values of six Lespedeza davurica ecotypes decreased quickly,and water use efficiency declined with stress increasing.P_n of Qinshui and Qinyuan ecotypes decreased rapidly with weak drought resistance.P_n of Yangquan and Jiaokou ecotypes decreased slowly with strong drought resistance.Lespedeza davurica population with strong drought resistance had stronger ability to recover with rehydration.Under drought stress,the water using efficiency of ecotypes with strong drought resistance was higher than that of ecotypes with weak drought resistance.The drought resistance ability of Lespedeza davurica ecotype were ranked as by comprehensive appraisal index:Yangquan>Jiaokoue>Taigu>Jingl>Qinshui>Qinyuan.