干旱及复水对不同抗旱性玉米光合特性的影响

Response of Drought and Rewatering to Leaf Photosynthetic Characteristics in Different Maize Varieties

采用盆栽试验,以抗旱性不同的玉米品种郑单958和陕单902为试材,在水分胁迫0、3、6、9天和复水3、6、9天条件下,通过气体交换和叶绿素荧光技术,研究水分胁迫和复水后叶片的气体交换、叶绿素荧光参数、叶绿素的变化特征。结果表明,随着水分胁迫天数的增加,陕单902的Pn、Ci、Gs、Fv/Fm、Yield、qP、Chl等指标的下降幅度均大于郑单958;NPQ上升的幅度大于郑单958。郑单958的光系统在水分胁迫时受到的伤害程度要小于陕单902。复水后郑单958的光合参数、叶绿素荧光参数、叶绿素等迅速恢复,陕单902光合参数及其他参数恢复缓慢。在水分胁迫条件下,耐旱玉米品种郑单958能保持良好的光合特性,在复水后,具有良好的生理补偿效应,是适应干旱环境的重要生理因素。

With two maize varieties Zhengdan958 and Shaandan902 as experimental materials,under the conditions of water stress for 0,3,6,9 d and rehydration for 3,6,9 d,the leaf gas exchange and chlorophyll fluorescence and chlorophyll content were studied in pot experiment.The results showed that with elongation of water stress days,the tested indexes of shaandan902 was greater than that of Zhengdan958,such as Pn（the net photosynthetic rate）,Ci（intercellular CO2 concentration）,Gs（stomatal conductance）,Fv/Fm（maximal efficiency of PSⅡ photochemistry）,yield（the effective quantum yield of photosystem Ⅱ）,qP（photochemical quenching）and chlorophyll;the ascending extent of NPQ（regulated energy dissipation of the quantum yield） was larger than Zhengdan958.The vulnerability of Zhengdan958＇s photoreaction system was less than Shaandan902 under water stress,so the photosynthetic parameters,chlorophyll fluorescence parameters and chlorophyll recovered rapidly after rewatering,whereas photosynthetic parameters and other parameters of Shaandan 902 recovered slowly.Under water stress conditions,drought-tolerant maize varieties Zhengdan 958 can maintain good photosynthetic characteristics,and has a good physiological compensation effects after rewatering,which are important physiological factors for adaptation to arid environments.