外源钙对干旱胁迫下甘草生理特性的影响

Effects of Exogenous Calcium on Physiological Characteristic of Glycyrrhiza uralensis under Drought Stress

目的:探讨外源钙对干旱胁迫下甘草生理特性的影响。方法:采用称重控水法模拟干旱胁迫,研究施用外源钙对干旱胁迫下甘草叶片叶绿素含量、光合特性、抗氧化酶活性和丙二醛含量的影响。结果:随着干旱胁迫程度的加重,甘草叶片净光合速率、气孔导度和胞间CO2浓度均呈先上升后下降趋势,叶绿素含量、蒸腾速率呈下降趋势;施用外源钙后,甘草叶片叶绿素含量、净光合速率、气孔导度、胞间CO2浓度、蒸腾速率在各干旱胁迫下均有不同程度提高。随着干旱胁迫程度的增加,甘草叶片丙二醛(MDA)含量、过氧化氢酶(CAT)活性持续升高,超氧化物歧化酶(SOD)、过氧化物酶(POD)活性呈先增加后下降的趋势;施用外源钙后,降低了MDA含量,提高了SOD、POD、CAT的活性。结论:施用外源钙可以有效缓解干旱胁迫对甘草造成的伤害,从而增强甘草对干旱的适应能力。

Objective:In order to reveal the effects of exogenous calcium on the physiological characteristic of Glycyrrhiza uralensis under drought stress.Methods:The paper studied the variation of exogenous calcium on the chlorophyll content,photosynthetic characteristics,antioxidant enzyme activity and MDA content at different drought stress with weighing control water.Results:The results showed that with the increase of drought stress,the photosynthetic rate,stomatal conductance and intercellular CO2 concentrations decreased after an initial increased,chlorophyll content and transpiration rate decreased.The application of exogenous calcium could effectively increase chlorophyll content,photosynthetic rate,stomatal conductance,intercellular CO2 concentrations and transpiration rate at different drought stress.The MDA and CAT of licorice leaves increased with the increase of drought stress,SOD and POD decreased after an initial increased.Exogenous calcium could reduce MDA content,improve SOD,POD and CAT activities.Conclusion:The application of exogenous calcium could effectively alleviate the injury on licorice caused by drought stress,and thereby enhanced the drought resistance of licorice.