干旱和施氮对苹果大苗的水分状况、生长和碳素分配的影响  

Response of water status,growth and carbon partitioning of apple seedlings to water-stressed and nitrogen addition

作　　者：薛浩 刘毅 吕英忠 张拥兵 王林[1] XUE Hao;LIU Yi;LYU Yingzhong;ZHANG Yongbing;WANG Lin(College of Forestry,Shanxi Agricultural University,Taigu 030815,Shanxi,China;Pomology Institute,Shanxi Agricultural University,Taigu 030815,Shanxi,China)

机构地区：[1]山西农业大学林学院,山西太谷030815 [2]山西农业大学果树研究所,山西太谷030815

出　　处：《经济林研究》2023年第3期115-123,149,共10页Non-wood Forest Research

基　　金：山西省重点研发计划项目(201903D221051);山西省应用基础研究项目(201801D121246)。

摘　　要：[目的]为苹果大苗的水分和养分管理提供理论参考。[方法]选用‘丹霞’苹果大苗为材料,分别设置正常浇水(土壤含水量为25%~30%)与干旱(土壤含水量为10%~15%)2个水分处理,每种水分条件下分别设置每株0、20、60 g氮肥施用量3个处理(分别以低氮、中氮、高氮表示)。在处理3个月后,测定苹果大苗的水分状况、光合作用指标、各部位生物量和非结构性碳水化合物(NSC)含量。[结果]在正常供水条件下:随着施氮量的增加,枝条水势降低,导水损失率增加,水分条件变差;中氮处理对净光合速率的促进作用最大,茎生物量随着施氮量增多显著增加,高氮处理下枝条和叶片的NSC含量均低于低氮处理。在干旱条件下,随着施氮量的增加,枝条水势降低,导水损失率升高,净光合速率和气孔导度降低,各部位生物量减少,枝条韧皮部及木质部的NSC含量降低。[结论]正常供水条件下,过量施氮导致苹果大苗水分状况变差,这会抵消氮对光合速率的促进作用,进而影响树木的生长和生物量积累。在干旱条件下,施氮进一步引起水分条件恶化,限制光合作用和生物量积累,同时过量施氮会导致NSC含量降低,可能进一步影响植株对干旱的适应能力,因此在干旱条件下应减少氮肥的施用量。【Objective】In order to provide a theoretical basis for water and nutrient management of apple saplings.【Method】The Malus pumila Mil.cv.Danxia was selected as experimental materials,and set up two water conditions named well-watered(water content of soil was 25%-30%)and water-stressed(water content of soil was 10%-15%).There were three nitrogen addition rates treatments:0,20 and 60 g/plant(represented by no nitrogen addition,medium nitrogen addition,and high nitrogen addition respectively)in each water condition.After three months of experiment treatment,the water status,photosynthesis,biomass,and non-structural carbohydrate(NSC)concentration of apple seedlings were measured.【Result】When the apple saplings were well-watered,with the increase of nitrogen addition,the water potential of the branches decreased,the percentage loss of conductivity(PLC)increased,and the water conditions deteriorated;The net photosynthetic rate was most promoted under medium nitrogen addition,and the stem biomass increased significantly with the increase of nitrogen addition.The NSC content of branches and leaves under high nitrogen treatment was lower than that under no nitrogen addition treatment.When the apple saplings were under water-stressed,with the increase of nitrogen addition,the water potential of the branches decreased,the PLC increased,the net photosynthetic rate and stomatal conductance decreased,the biomass of each part decreased,and the concentration of NSC in the phloem and xylem of the branches significantly decreased.【Conclusion】The nitrogen addition can leads to a deterioration in the water status of apple saplings when it is well-watered,while high nitrogen addition leads to a deterioration in the water status that offsets the promotion of nitrogen on photosynthetic rate,thereby affecting the growth and biomass accumulation of trees.Under water-stressed,nitrogen addition further leads to deterioration of water conditions,limiting photosynthesis and biomass accumulation,while high nitrogen application

关 键 词：苹果大苗 施氮 干旱 水分状况 光合速率 生长 非结构性碳水化合物 

分 类 号：S661.1[农业科学—果树学]