小麦叶片水分利用效率及相关生理性状的关系研究

The Relationship between Water Use Efficiency and Related Physiological Traits in Wheat Leaves

利用19个抗旱性不同的小麦品种,对干旱状态下叶片水分利用效率和光合速率、蒸腾速率等12个指标之间的关系进行了研究。结果表明,叶片水分利用效率与叶片光合速率、蒸腾速率、气孔导度、胞间二氧化碳浓度、水势和叶片离体失水速率之间的关系密切,说明这些生理性状是瞬间和短时期叶片水分利用效率的直接影响因素;而与叶片抗氧化酶活性、蜡质含量、叶片温度和相对含水量相关性不大。因此认为,应该有针对性地研究与水分利用效率关系密切的生理性状,为小麦抗旱节水遗传育种研究提供理论依据。

Water shortage is a main limited factor to agriculture and crop production, so it is important to improve the crop water use efficiency （WUE） in limited water resource. The leaf WUE is the physiological foundation for improving field water use efficiency. In early researches only one or a few wheat cuhivars were employed to analyze the relationship between WUE and single or a few physiological traits, or only the daily variation regularity of leaf WUE and relevant physiological traits studied. 19 wheat cuhivars, possessing different drought-resistance, from different winter wheat growth regions in China,were employed in this drought-resistance trial, with no irrigation during whole growth period, for analyzing the correlation between leaf WUE and other 11 traits of wheat flag leaf, including photosynthetic rate （Pn）, transpiration rate （ Tr）, stomata conductance （ Cond）, intercellular CO2 concentration （ Ci ）, water potential （ kttW ）, water loss rate of cutting leaves （RWL）, anti-oxidative enzyme activities. The results showed that there were significant linear correlations between leaf WUE and six physiological traits including P,,, Tr, Cond, Ci, ψw and RWL, so that the six traits were considered to be the direct influence factors to instantaneous leaf WUE to which more attention should be paid in wheat breeding. There were insignificant correlations between leaf WUE and other four traits including anti-oxidative enzyme activities wax content T （leaf surface temp） and RWC （relative water content） were considered to be indirect influence factor for short-term leaf WUE. Otherwise, there were significant positive correlations between leaf Tr and Cond,ψW and RWL, RWL and Tr Cond, RWC and ψw, POD activity and SOD activity;and there were significant negative correlations between Tleaf and Cond, Tleaf and RWL. It is suggested that more attention should be paid to the research on the relationship of WUE and water channel protein, the functional genome of wheat drought-resistance and WUE, which must be helpful to improving drought resistance and water use efficiency in wheat.