干旱胁迫对马缨杜鹃生长和光合生理特征的影响  

Effects of drought stress on growth and photosynthetic physiological characteristics of Rhododendron delavayi

作　　者：曾松 欧静[1] 田奥 李苇洁 林世成 王洪飞 周玉梅 ZENG Song;OU Jing;TIAN Ao;LI Wei-jie;LIN Shi-cheng;WANG Hong-fei;ZHOU Yu-mei(College of Forestry,Guizhou University,Guiyang 550025,China;Guizhou Institute of Mountainous Resources,Guiyang 550001,China)

机构地区：[1]贵州大学林学院,贵阳550025 [2]贵州省山地资源研究所,贵阳550001

出　　处：《西南农业学报》2023年第12期2670-2677,共8页Southwest China Journal of Agricultural Sciences

基　　金：贵州省科技计划项目[黔科合基础-ZK(2022)一般275];贵州省科技计划项目[黔科合基础-ZK(2021)一般100号];国家自然科学基金青年基金项目(42101283);贵州科学院青年基金项目[黔科院J字(2021)22号];贵州科学院博士科研启动经费项目[黔科院R字(2021)5号]。

摘　　要：【目的】探明干旱胁迫下马缨杜鹃生长指标和光合特性的变化规律,为马缨杜鹃资源的开发利用和抗旱新品种的选育提供依据。【方法】以2年生马缨杜鹃幼苗为研究对象,采用盆栽控水法结合单因素方差分析及回归分析研究不同土壤含水量[80%~100%(CK),60%~80%(FC_(60))、40%~60%(FC_(40))、30%~40%(FC_(30))、20%~30%(FC_(20))和10%~20%(FC_(10))]对马缨杜鹃幼苗株高、地径、叶片生长指标(芽长、新叶数、单叶面积和叶片相对含水量等)和光合指标(叶绿素a、叶绿素b和净光合速率等)的影响,确定不同指标的关键土壤含水量阈值,揭示其抗旱能力和适应机制。【结果】干旱胁迫下株高相对生长量为25.68%~49.86%,各处理均低于CK,呈先降后升再降趋势;FC_(60)显著高于FC_(40)、FC_(20)和FC_(10),FC_(40)显著低于FC_(30),FC_(10)显著低于其余处理;地径相对生长量为8.92%~13.03%,呈先升后降趋势,FC_(60)最大,但各处理间差异不显著;株高和地径与土壤含水量回归关系均未达显著水平。叶片各生长指标依次为芽长0.63~4.60 cm,新叶数8.82~21.86片,落叶数2.00~4.36片,总叶数21.36~34.36片,单叶面积25.33~70.42 cm^(2),随干旱胁迫加剧芽长和新叶数均呈先升后降趋势,且FC_(60)均显著高于FC_(30)、FC_(20)和FC_(10);落叶数呈先升后降再升趋势,FC_(20)和FC_(10)显著大于CK;总叶数呈先升后降趋势,FC_(60)显著高于FC_(10);单叶面积呈下降趋势,CK显著高于其余处理,FC_(60)显著高于除FC_(40)外的其余处理,FC_(40)显著高于FC_(20)和FC_(10);除叶片相对含水量外,其余生长指标均与土壤含水量回归关系显著;芽长及新叶率最适土壤含水量分别为25.97%和25.18%,土壤干旱缓冲阈值分别为16.30%~32.78%和15.08%~32.78%。不同干旱胁迫叶绿素a含量、叶绿素b含量和蒸腾速率依次为0.99~2.15 mg/g、0.12~0.14 mg/g和0.46~1.51 mmol/(m^(2)·s),且差异显著;气孔导度[0.01~0.03 mmol/(m^(2)·s)]和蒸腾速率与【Objective】The changes in growth indicators and photosynthetic characteristics of Rhododendron delavayi under drought stress were explored,which provided a basis for developing and utilizing of R.delavayi resources and breeding of new drought resistant varieties.【Method】Using 2⁃year⁃old R.delavayi seedlings as the research object,the pot⁃controlled water method,one⁃way ANOVA and regression a⁃nalysis were combined to study the effects of different soil moisture contents[80%-100%(CK),60%-80%(FC_(60)),40%-60%(FC_(40)),30%-40%(FC_(30)),20%-30%(FC_(20)),10%-20%(FC_(10))]on the plant height,ground diameter,leaf growth indicators(such as bud length,number of new leaves,single leaf area,relative leaf water content)and photosynthetic indicators(such as chlorophyll a,chlorophyll b,and net photosynthetic rate)of R.delavayi seedlings,and to determine key soil water content thresholds for different indicators,thereby revealing their drought resistance and adaptation mechanisms.【Result】Under drought stress,the relative growth of plant height was 25.68%-49.86%,and all treatments were lower than CK,showing a first decreasing,then increasing and then decreasing trend;FC_(60)was significantly higher than FC_(40),FC_(20)and FC_(10),FC_(40)was significantly lower than FC_(30),and FC_(10)was significantly lower than other treatments;The relative growth of ground diameter ranged from 8.92%to 13.03%,showing a first increasing and then decreasing trend,with FC_(60)being the largest,but the differences among different treatments were not significant;The regression relationship between two indicators(plant height and ground diameter)and soil moisture content did not reach a significant level.The growth indicators of leaves were as follows:bud length 0.63-4.60 cm,number of new leaves 8.82-21.86,number of fallen leaves 2.00-4.36,total number of leaves 21.36-34.36,and single leaf area 25.33-70.42 cm^(2).As drought stress intensified,both bud length and number of new leaves showed a first increasing and then decreasing t

关 键 词：干旱胁迫 马缨杜鹃 生长指标 光合特征 

分 类 号：S685.21[农业科学—观赏园艺]