南疆地区棉花叶片水分利用效率的日内动态变化特征

Diurnal Variation Characters of Water Use Efficiency of Cotton Leaves in South Xinjiang

[目的]研究南疆棉花叶片水分利用效率的日动态变化。[方法]在新疆巴州水管处重点灌溉试验站利用LCpro+全自动便携式光合仪对试验田内棉花光合作用进行系统监测,同时将数据转化为棉叶水分利用效率(WUE)并进行动态特征分析。[结果]在日内,棉叶光合速率变化呈双峰型曲线,蒸腾速率的变化因棉叶温度差异呈双峰型或单峰型曲线;光合和蒸腾日内动态都具有不对称性,且二者动态反向;棉叶水分利用效率的日动态呈双峰型曲线,上午棉叶水分利用效率高于下午,且在不同叶位之间差异较大,自主茎第2叶向下依次减小;花铃期主茎不同叶位之间的水分利用效率变幅大于蕾期。[结论]该研究为提高棉花叶片水分利用效率提供了科学依据。

[Objective]The research aimed to study the diurnal variation for the water use efficiency（WUE）of the cotton leaf in southern Xinjiang.[Method] The photosynthesis of the cotton in the tested field was made for the system monitoring by using LCpro＋ portable automatic photosynthetic apparatus in the key irrigation experiment station in Bazhou Water Management Office,Xinjiang,at same time,the monitored data was transformed into the cotton leaf WUE and made for the variation character analysis.[Result] Within a day,the photosynthetic rate of the cotton leaves showed a bimodal curve,and the transpiration rate appeared to be bimodal curve or unimodal one because of the differences on the temperature in the cotton leaves.The diurnal dynamic characteristic of the photosynthesis and transpiration both showed the asymmetric and both dynamic reversed.The diurnal variation of leaf WUE also showed a bimodal curve,and the cotton leaf WUE in the morning was higher than that in the afternoon.There was a large difference among the different leaf position and the leaf WUE decreased from the second leaf to the last leaf of main stem orderly.The variation of the leaf WUE among the different leaf position of main stem in the flower-belling stage was greater than that in the flower-budding period.[Conclusion]The study provided the scientific basis of increasing the cotton leaf WUE.