春小麦叶片气体交换与产量对干旱响应的阈值差异  

Difference of response thresholds between leaf gas exchange and yield to drought for spring wheat

作　　者：赵福年[1] 刘江 张强[1,3] 王润元[1] 王鹤龄[1] 张凯[1] 赵鸿[1] 齐月[1] 陈斐[1] ZHAO Funian;LIU Jiang;ZHANG Qiang;WANG Runyuan;WANG Heling;ZHANG Kai;ZHAO Hong;QI Yue;CHEN Fei(Lanzhou Institute of Arid Meteorology,China Meteorological Administration/Key Laboratory of Arid Climatic Change and Disaster Reduction of Gansu Province/Key Laboratory of Arid Climate Change and Disaster Reduction of China Meteorological Administration,Lanzhou 730020,China;College of Resources and Environment,Gansu Agricultural University,Lanzhou 730070,China;Gansu Meteorological Bureau,Lanzhou 730020,China)

机构地区：[1]中国气象局兰州干旱气象研究所/甘肃省干旱气候变化与减灾重点实验室/中国气象局干旱气候变化与减灾重点开放实验室,兰州730020 [2]甘肃农业大学资源与环境学院,兰州730070 [3]甘肃省气象局,兰州730020

出　　处：《中国生态农业学报（中英文）》2023年第11期1733-1744,共12页Chinese Journal of Eco-Agriculture

基　　金：国家自然科学基金项目(42230611,42005097,42175192);博士后科研基金项目(BSH2022001)资助。

摘　　要：叶片气体交换过程是作物干物质及产量形成的基础,在干旱发展过程中作物叶片气体交换对水分胁迫存在阈值响应,众多相关生理指标也以此为基础用于监测作物受旱状况。然而作物叶片气体交换过程与产量对干旱的响应阈值是否具有同步性,目前尚不清楚,这在一定程度上影响了利用作物生长期叶片气体交换相关生理指标监测农业干旱的准确性。本研究通过控制试验确定春小麦叶片气体交换对干旱的响应阈值,并利用该阈值特征参数化春小麦生长模型,从而设计水分控制模拟试验,分析春小麦产量对干旱的阈值响应特征及其与叶片气体交换指标阈值的差异。结果表明:春小麦气孔导度对土壤有效含水量的响应阈值为0.50,大于蒸腾速率与净光合速率的响应阈值(0.40)。用净光合速率对土壤有效含水量的响应阈值参数化春小麦生长模型,能够准确模拟春小麦地上部生物量和产量的变化。春小麦地上部生物量与产量对根系层土壤有效含水量的响应阈值为0.18,明显小于叶片气体交换指标对土壤有效含水量的响应阈值。证明了利用作物生育期间叶片气体交换等生理指标表征作物受旱状况,反映作物最终产量降低程度会存在一定问题。本研究结果可为农业干旱监测、预测及干旱影响评估提供参考依据。Leaf gas exchange is the basis for crop biomass and yield formation.During drought development,the leaf gas exchange exhibits a threshold response to water stress,and many related physiological indicators are based on this response to monitor drought severity in crops.However,the focus of agricultural production is crop yield,and it is unclear whether the response threshold of leaf gas exchange indicators used to monitor drought is synchronous with that of crop yield to drought.To some extent,this affects the accuracy of agricultural drought monitoring using physiological indicators related to leaf gas exchange.In this study,based on drying experiments,changes in leaf gas exchange in spring wheat during the drought development process were observed and analyzed.The response threshold of leaf gas exchange in spring wheat to drought was determined and used to parameterize the crop model for spring wheat.Drought stress simulation experiments were designed to analyze the response threshold characteristics of spring wheat yield to drought and the differences in the threshold of leaf gas exchange.The results showed that the response threshold of stomatal conductance for spring wheat to available soil water content was 0.50,which was higher than that of transpiration rate and net photosynthetic rate(0.40).The aboveground biomass and yield of spring wheat were simulated by parameterizing the crop model for spring wheat with the response threshold of the net photosynthetic rate to the available soil water content.The model simulation values explained more than 70%of the observed variation,and the results were highly significant(P<0.01).The relative root mean square error between the model simulation and observed values was less than 30%,indicating a high overall simulation accuracy of the model.The consistency index was greater than 0.85,and the relationship slope between the simulated and observed values was between 1.00 and 1.50.This indicates that the proposed crop model can accurately simulate changes in the abovegrou

关 键 词：响应阈值 水分胁迫 叶片气体交换 产量 作物模型 春小麦 

分 类 号：S166[农业科学—农业气象学]