黄瓜光合特征及水分利用效率对土壤含水量的响应  

Response of Photosynthetic Characteristics and Water Use Efficiency of Cucumber to Soil Water Content

作　　者：李生平[1] 武雪萍[1] 高丽丽[1] 龙怀玉[1] 李景[1] 王碧胜 党建友 裴雪霞 LI ShengPing WU XuePing GAO LiLi LONG HuaiYu LI Jing WANG BiSheng DANG JianYou PEI XueXia(Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081 Wheat Research Institute, Shanxi Academy of Agricultural Science, Linfen 041000, Shanxi)

机构地区：[1]中国农业科学院农业资源与农业区划研究所,北京100081 [2]山西农业科学院小麦研究所,山西临汾041000

出　　处：《中国农业科学》2017年第15期2993-3005,共13页Scientia Agricultura Sinica

基　　金：国家"863"计划(2013AA102901);国家科技支撑计划(2015BAD22B03);国家重点研发计划(2016YFD0300804)

摘　　要：【目的】采用新型负压灌溉系统,研究不同系统供水负压控制下的土壤含水量对黄瓜叶片碳同化和蒸腾耗水协同作用的影响,旨在分析与确定黄瓜适宜土壤含水量范围,为黄瓜的节水生理研究提供参考依据。【方法】通过遮雨网室盆栽试验,设4个系统供水负压水平(W1:0,W2:-5 k Pa,W3:-10 k Pa,W4:-15 k Pa),研究不同土壤含水量对黄瓜光合特征、产量和水分利用效率的影响。【结果】同一系统供水负压下,黄瓜整个生育期土壤含水量基本保持稳定,W1、W2、W3和W4处理下控制的土壤相对含水量(RSWC)分别为(103.8±1.2)%、(88.7±3.7)%、(77.4±4.5)%和(61.8±3.2)%。RSWC在61.8%-88.7%范围,黄瓜叶片气孔导度(Gs)和蒸腾速率(Tr)日均值均随着土壤含水量降低而下降。黄瓜叶片净光合速率(Pn)和LWUE在同一生育时期的日均值与土壤相对含水量(RSWC)均呈极显著抛物线型关系(P<0.01),且不同生育时期Pn和LWUE的最高值对应的RSWC不相同。黄瓜植株干物质量和产量均以W2(RSWC为88.7%)处理最高,黄瓜经济水分利用效率以W3(RSWC为77.4%)处理最高。【结论】负压灌溉条件下,达到黄瓜叶片碳同化和蒸腾耗水之间协同平衡关系的适宜土壤相对含水量为:开花期RSWC为70%—93%、盛瓜期RSWC为78%—103%、末瓜期RSWC为73%—104%。在此范围内,黄瓜能够获得较大的叶面积、蒸腾速率、光合速率和水分利用效率,从而获得较高的干物质量和黄瓜产量。【Objective】Water deficit is the principal factor affecting cucumber production.However,the mechanisms for the decline of photosynthesis in leaves of cucumber and the synergistic action between carbon assimilation and transpiration water consumption under different water stresses were not very clear.The objective of this study was to investigate the processes and mechanisms of drought stress on photosynthesis,to study the impact of soil water content on carbon assimilation and transpiration water consumption,and to analyze the optimum range making cucumber grow better,which would supply the reference basis about cucumber water-saving physiology.【Method】The pot experiments were conducted in the rain-proofing solarium and two factors were designed：irrigation and nitrogen fertilization.There were five irrigations levels（W1：0,W2：-5 kPa,W3：-10 kPa,W4：-15 kPa）.【Result】During cucumbers growth period,soil water content could keep stability essentially under the same negative hydraulic head supplied by the negatively pressurized irrigation system.The relative soil water content（RSWC） controlled by W1,W2,W3 and W4 were（103.8±1.2）%,（88.7±3.7）%,（77.4±4.5）% and（61.8±3.2）%,respectively.When RSWC was between 61.8% and 88.7%,both the daily mean value of stomatal conductance（Gs） and transpiration rate（Tr） significantly decreased with reducing soil water content,which could maintain leaf water use efficiency（LWUE） at a relatively high level to accommodate water stress.The daily mean values of net photosynthetic rate and LWUE at 3 growth stages were parabolic correlated to the value of relative soil water content.Nevertheless,the values of RSWC were different when the values of Pn and LWUE were maximum at different growth stages.When RSWC was 88.7%,plant dry weight and yield were the maximum,while water use efficiency（WUE） was the highest as RSWC was 77.4%.【Conclusion】Appropriate ranges of relative soil water content were between 70% and 93% at flowering stage,bet

关 键 词：土壤含水量 黄瓜 水分胁迫 光合作用 产量 水分利用效率 

分 类 号：S152.7[农业科学—土壤学]