利用碳同位素分辨率表征沟灌番茄水分利用效率  

Stable carbon isotope discrimination on water use efficiency of field tomato under furrow irrigation

作　　者：魏镇华[1] 杜太生[1] 张娟[1] 徐淑君[1] 

机构地区：[1]中国农业大学中国农业水问题研究中心,北京100083

出　　处：《农业工程学报》2013年第7期58-65,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(51079147;51222905);教育部"新世纪优秀人才支持计划"项目(NCET-11-0479)

摘　　要：为了进一步探索沟灌条件下作物水分利用效率提升机理,利用稳定碳同位素对水分利用效率(WUE)的指示特性,研究了隔沟交替灌溉(AFI)和常规沟灌(CFI)条件下大田番茄不同部位碳同位素分辨率(Δ13C)与叶片和产量水平水分利用效率的关系。研究结果表明:不同沟灌条件下果实成熟期的叶片碳同位素分辨率(ΔL)、果实碳同位素分辨率(ΔF)分别为19.27‰～20.25‰和18.07‰～20.04‰,ΔL与叶片水平瞬时水分利用效率(WUEi)、内在水分利用效率(WUEn)均呈负相关,且ΔL对WUEn的指示性优于WUEi。ΔL、ΔF均与产量水平水分利用效率(WUEET)呈负相关。AFI条件下ΔL与WUEn、WUEET的相关性较CFI更为显著,沟灌条件下果实成熟期的叶片碳同位素分辨率可作为表征作物WUE的量化指标。Carbon isotope discrimination value （Δ13C） was an integrative reflection to the rate of intercellular CO2 concentration（Ci） and air CO2 concentration （Ca） in a period, and Ci/Ca suggested a relative amount of photosynthetic rate （Pn） and stomatal conductance （gs） corresponding to CO2 demand and supply respectively, and then Ci/Ca would change significantly and affect the water use efficiency （WUE） ultimately with the variation of Pn or gs, which had the same impact factor with stable carbon isotope composition in crops.Δ13C and carbon isotope ratio （δ13C） could characterize the WUE during the entire life period of crops. Furthermore, the measurement for δ13C of different parts in crops could reflect cumulative WUE at different time scales, thus overcoming the limit of any other methods that could just measure instantaneous WUE at a time scale only. Therefore, Δ13C could well reflect water use efficiency at yield level （WUEET）, and be used to infer instantaneous water use efficiency （WUEi） and intrinsic water use efficiency（WUEn） at leaf level, which was recognized as a reliable way to estimate the crop WUE at a long term. The current research on indicating the relationship betweenΔ13C of crop tissue and crop WUE were mainly focused on crops such as wheat, rice, sugar beet and maize under a water deficit, and less on tomatos under alternate partial root-zone furrow irrigation （AFI） and conventional furrow irrigation （CFI）. In order to further investigate the water use mechanism on different parts of crops under different furrow irrigation, this research combined theoretical analysis with field experiments, integrating WUE research on different scales through carbon isotope’s instruction on WUE, then analyzed the relationship between different parts ofΔ13C in tomato with WUE at different scales to further explain the water use process and transferring rule in crop’s different parts under partial root-zone irrigation. The experiment was carried out at the Ex

关 键 词：灌溉 碳 同位素 分辨率 水分利用效率指示 番茄 

分 类 号：S275[农业科学—农业水土工程]