冬小麦光合特性对CO_(2) 浓度与土壤含水量的响应机制  

Response mechanism of photosynthetic characteristics of winter wheat to CO_2 concentration and soil water content

作　　者：周晓旭[1,2] 张玉翠[1] 吴林[1,3] 沈逸群[4] 姜寒冰[1,2] 沈彦俊[1] ZHANG Yucui;ZHOU Xiaoxu;WU Lin;SHEN Yiqun;JIANG Hanbing;SHEN Yanjun(Key Laboratory of Agricultural Water Resources, Chinese Academy of Sciences / Key Laboratory of Water Saving Agriculture, Hebei Province / Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences,Shijiazhuang 050022, China;University of Chinese Academy of Sciences, Beijing 100049, China;College of Biologic and Geographic Sciences, Qinghai Normal University, Xining 810000, China;Hebei Normal University Attached School, Shijiazhuang 050011, China)

机构地区：[1]中国科学院农业水资源重点实验室/河北省节水农业重点实验室/中国科学院遗传与发育生物学研究所农业资源研究中心,石家庄050022 [2]中国科学院大学,北京100049 [3]青海师范大学生命与地理科学学院,西宁810000 [4]河北师范大学附属中学,石家庄050011

出　　处：《中国生态农业学报》2017年第7期1034-1041,共8页Chinese Journal of Eco-Agriculture

基　　金：国家重点研发计划课题(2016YFC0401403);国家自然科学基金项目(91425302,41471027,31400375)资助~~

摘　　要：光合作用是衡量植物对环境响应的重要指标,通过光响应曲线拟合量化光合特征,可从生理机制方面揭示出植物在不同生长环境下自身的调节与适应机制。本文利用Li-6400便携式光合仪测定了冬小麦在4种不同处理条件下灌浆期旗叶的光响应曲线,采用直角双曲线模型(RHM)、非直角双曲线模型(NRHM)、直角双曲线修正模型(RHMM)、指数模型(EM)和指数改进模型(MEM)对光响应数据进行拟合,分析了不同CO_(2)浓度和土壤含水量对冬小麦光合特征的影响。结果表明,直角双曲线修正模型对各处理下冬小麦光响应曲线和光响应曲线参数的拟合值都与实测值较为接近,拟合效果最好;随着CO_(2)浓度升高,各水分处理下冬小麦表观量子效率(α)、光饱和点(LSP)和最大净光合速率(P_(nmax))增大,光补偿点(LCP)和暗呼吸(R_d)降低,即CO_(2)浓度升高能有效增加冬小麦的光能转化率和光能利用范围,提高冬小麦的光合能力;随着土壤含水量的降低,冬小麦光补偿点(LCP)和暗呼吸速率(R_d)升高,但表观量子效率(α)、光饱和点(LSP)和最大净光合速率(Pnmax)降低,即冬小麦虽然能通过提高初始光合效率抵消一部分干旱胁迫的影响,但干旱胁迫仍会降低冬小麦光合能力;此外,CO_(2)浓度的增加能抵消部分冬小麦因干旱胁迫引起的光合能力降低。Photosynthesis can reveal the response of plant to the environment.By fitting the light response curve,the physiologicalmechanism of plant under different growth conditions could be clarified.Under four treatments of two CO2concentrations(400and750?mol·mol?1)and two soil water contents[45%(drought stress)and75%(suitable water condition)of field capacity],Li-6400portable photosynthetic system was used to measure the light response curves of flag leaves of winter wheat.Five photosynthetic light response models,including rectangular hyperbolic model(RHM),non-rectangular hyperbolic model(NRHM),rectangular hyperbolic modified model(RHMM),exponential model(EM)and modified exponential model(MEM),were used to fit the light response curve of winter wheat.The effects on photosynthesis of winter wheat of different treatmentswere analyzed.The results showed that the light saturation point(LSP)and the max net photosynthetic(Pnmax)fitted by therectangular hyperbolic model and the non-rectangular hyperbolic model were larger than the measured values.The rectangularhyperbolic model and the non-rectangular hyperbolic model could not fit the photoinhibition.Meanwhile,the exponentialmodel could simulate well of LSP and Pnmax while could not show the photoinhibition,either.Although the modified exponentialmodel could reveal the photoinhibition,there were serious bias in the parameters of light response curve,and the parameterswere lower than the other models.In general,the rectangular hyperbolic modified model was the best model for the simulationof light response curve and its parameters.The increase of CO2concentration effectively improved the apparent quantumefficiency,light saturation point and maximum net photosynthetic rate of winter wheat,and reduced the light compensationpoint and dark respiration rate of winter wheat.Meanwhile,winter wheat energy conversion rate,maximum net photosyntheticrate,light use scope and initial photosynthetic efficiency were increased,which suggested that the increase of CO2concentration could eff

关 键 词：冬小麦 CO_(2) 浓度升高 干旱胁迫 光响应曲线模型 光合能力 

分 类 号：S311[农业科学—作物栽培与耕作技术]