干旱胁迫对杜仲截干苗生长和光合特性的影响  

Effects of Soil Drought on the Growth and Leaf Photosynthetic Characteristics of Eucommia ulmoides Seedlings

作　　者：张芸香[1,2] 张荣荣 王怡霖 常淑君[1,3] 郭晋平 ZHANG Yun-xiang;ZHANG Rong-rong;WANG Yi-lin;CHANG Shu-jun;GUO Jin-ping(College of Forestry,Shanxi Agricultural University,Taigu 030801,Shanxi,China;Shanxi Key Laboratory of Functional Oil Tree Cultivation and Research,Taigu 030801,Shanxi,China;3 Dupont Company,Delaware 19803,Wilmington,USA)

机构地区：[1]山西农业大学林学院,山西太谷030801 [2]北方功能油料树种培育与研发山西省重点实验室,山西太谷030801 [3]美国杜邦公司,特拉华州威尔明顿19803

出　　处：《西北林学院学报》2020年第4期1-6,共6页Journal of Northwest Forestry University

基　　金：山西省林业科技创新项目(2018LYCX32);北方功能油料树种培育与研发山西省重点实验室(201805D111010)。

摘　　要：树木对干旱胁迫的响应方式和机制是树种生态适应性对策的重要特征,对掌握树种生态习性采取合理的栽培技术措施具有重要意义。为阐明土壤干旱对杜仲苗期生长和光合特性的影响,以3年生杜仲截干苗为研究对象,采用盆栽称重法控制土壤含水量,研究充分供水、中度干旱和重度干旱3种不同土壤供水条件对杜仲枝条和根系生长、叶片光合特性的影响。结果表明:1)随着干旱程度的增加杜仲新枝和新根的生物量显著降低,新枝生长量与对照相比减少了30%和50%,新根生长量减少了14.1%和22.6%。2)干旱胁迫对叶片气孔密度和叶脉密度影响显著,气孔密度与对照相比分别增加19.4%和38.2%,叶脉密度增加8.5%和16%。3)叶片的光合能力随着胁迫程度的增加而降低,净光合速率下降了17.9%和33.1%,蒸腾速率下降了24.8%和45.7%,最大净光合速率下降了24.4%和43.1%。4)非光化学淬灭系数增加了77.8%和142%。因此,干旱胁迫抑制了杜仲的生长,新枝和新根生长量显著降低,使其适应干旱环境的自我调节能力显著增强;同时叶通过降低气孔传导性减少蒸腾耗水,增加光能热耗散避免光系统受到损伤,以适应干旱缺水的环境。The modes of responses and mechanism of the trees to drought stress are important characteristics of ecological adaptability of the trees.The understanding of the modes and mechanism is of important significance to clear the ecological habit of tree species and to take efficient cultivation measures.To illuminate the growth and leaf photosynthetic changes of Eucommia ulmoides under soil drought conditions,3-year-old E.ulmoides seedlings were potted as materials and the soil moisture were controlled by using weighting method.Changes of root,branch and leaf growth,leaf photosynthetic characteristics and chlorophyll a fluorescence characteristics were investigated under three soil moisture conditions(well watered,control;moderate drought,MD;and severe drought,SD).The results showed that 1)soil drought significantly decreased the biomass of the new branches and roots.Compared to the control,the dry weight of new branches reduced by 30%and 50%under MD and SD,respectively(the same below),the biomass of new roots were reduced by 14.1%and 22.6%.2)The stomatal density and vein density increased by 19.4%and 38.2%,and the vein density increased by 8.5%and 16%,respectively with the increase of drought degree.3).Drought stress significantly reduced photosynthetic capacity of the leaves,the net photosynthetic rate decreased by 17.9%and 33.1%,the transpiration rate decreased by 24.8%and 45.7%,the maximum net photosynthetic rate decreased by 24.4%and 43.1%.4)Non-photochemical quenching coefficients increased by 77.8%and 142%.It was concluded that drought stress inhibited the growth of E.ulmoides seedlings,manifested by the significant decreases of the growth of new branches and roots,and resulted in the promotion of self-regulation capacity to drought stress.Decreased leaf photosynthetic capacity could lead to the reduced biomass accumulation.Decreased leaf transpiration water consumption and increased thermal dissipation could avoid the optical system damage,which could be helpful to adapt to soil water deficit conditions.

关 键 词：杜仲 干旱胁迫 光合特性 

分 类 号：S718.43[农业科学—林学]