干旱胁迫对白花泡桐幼苗根、叶形态特征和生理变化的影响  

Effects of drought stress on root and leaf morphological characteristics and physiological changes in Paulownia fortunei seedlings

作　　者：王豪杰 侯月爽 陈静[1] 曹静静 赵振利[1] 范国强[1] 孔德良 WANG Haojie;HOU Yueshuang;CHEN Jing;CAO Jingjing;ZHAO Zhenli;FAN Guoqiang;KONG Deliang(College of Forestry,Henan Agriculture University,Zhengzhou 450046,China)

机构地区：[1]河南农业大学林学院,河南郑州450046

出　　处：《河南农业大学学报》2023年第5期784-793,共10页Journal of Henan Agricultural University

基　　金：国家自然科学基金项目(32171746);河南省特色骨干林学学科群建设经费;河南农业大学高层次人才引进启动费项目(30500854);河南省留学人员科研择优资助经费项目(30602423)。

摘　　要：【目的】探究白花泡桐幼苗根、叶形态特征和生理过程在干旱胁迫下的变化及其之间的相互关系,进一步揭示其干旱适应策略,为泡桐的抗旱研究提供参考。【方法】以白花泡桐幼苗为研究对象,采用盆栽控水法,设置3个水分梯度处理,研究干旱胁迫对白花泡桐幼苗的根、叶形态特征和生理过程的影响。【结果】(1)干旱胁迫下白花泡桐幼苗叶片厚度减小、比叶面积和组织密度增加,根系直径减小、比根长和组织密度增加。(2)干旱胁迫严重限制了白花泡桐幼苗叶片的光合生理活性,随着干旱胁迫的增加,白花泡桐幼苗叶片最大净光合速率降低,暗呼吸速率不变,光补偿点和光饱和点增加。(3)中度干旱胁迫时,白花泡桐幼苗细根呼吸速率和分泌速率同时增加,重度干旱胁迫时,细根呼吸速率持续上升,分泌速率有所降低。【结论】干旱胁迫造成白花泡桐幼苗叶片光合能力降低,比叶面积增加。中度干旱时的根更细、比根长更长,具有更高的呼吸和分泌速率,干旱程度继续增加后,根呼吸速率增加,根分泌速率显著降低。【Objective】We aim to explore changes in root and leaf morphological traits and physiological processes in Paulownia fortunei seedlings under drought stress as well as their relationships.Unraveling the strategies of Paulownia fortunei in dealing with drought stress is important for subsequent researches on drought resistance for Paulownia fortunei breading.【Method】Paulownia fortunei seedlings were selected and suffered from different drought treatments with three water gradients by potted water control method,and root and leaf morphological traits and physiological processes for Paulownia fortunei seedlings were examined.【Result】(1)Under drought stress,leaf thickness decreased,specific leaf area and tissue density increased,while root diameter decreased,and specific root length and tissue density increased.(2)Drought stress severely restricted the photosynthetic activity in seedling leaves.With the increase of drought stress,maximum net photosynthetic rate decreased,dark respiration rate remained unchanged,light compensation point and light saturation point increased.(3)Under moderate drought stress,both fine root respiration rate and secretion rate all increased,while under severe drought stress,fine root respiration rate continued to increase and secretion rate decreased.【Conclusion】Drought stress causes a decrease in leaf photosynthetic capacity and an increase in specific leaf area in Paulownia fortunei seedlings.For roots under moderate drought,they tended to be thinner,and have longer root length per unit dry mass and higher respiration and secretion rates.When the drought was more severe,root respiration rate increased while root secretion rate was significantly reduced.

关 键 词：白花泡桐 干旱胁迫 形态策略 光响应曲线 根系呼吸 根系分泌 

分 类 号：S792.43[农业科学—林木遗传育种]