马缨杜鹃幼苗生长对土壤水分胁迫的响应及其生理机制  

Growth response of Rhododendron delavayi seedlings to the soil water stress and its physiological mechanism

作　　者：田奥 李苇洁 曹洋 贾真真 曾松 TIAN Ao;LI Wei-Jie;CAO Yang;JIA Zhen-Zhen;ZENG Song(Institute of Mountain Resources of Guizhou Province,Guiyang 550001,China;Botanical Garden of Guizhou Province,Guiyang 550009,China;School of Forestry,Guizhou University,Guiyang 550025,China;and 4Guizhou Branch of China Construction Fourth Bureau Guizhou Investment Co.,LTD.,Guiyang 550001,China)

机构地区：[1]贵州省山地资源研究所,贵阳550001 [2]贵州省植物园,贵阳550009 [3]贵州大学林学院,贵阳550025 [4]中建四局贵州投资有限公司贵州分公司,贵阳550001

出　　处：《植物生态学报》2025年第3期488-501,共14页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(42101283);贵州省科技计划项目(黔科合基础-ZK[2022]一般275)。

摘　　要：杜鹃(Rhododendron)是极具观赏价值的花卉,中国是全世界杜鹃资源最丰富的国家,对杜鹃资源的开发利用具有很大潜力。在全球变暖背景下,杜鹃遭受水分胁迫的风险快速增大,但关于水分胁迫对杜鹃生长及生理生态指标的影响尚缺乏深入研究。该研究通过马缨杜鹃(R.delavayi)幼苗的土壤水分梯度实验,研究其株高及地径生长差异,并建立与生理指标的统计关系,以期为杜鹃保护与管理等提供理论基础。2022年3月11日至10月15日,用马缨杜鹃的二年生幼苗进行盆栽实验,设计的土壤水分含量分别为田间持水量的15%、25%、35%、50%、70%、90%。分别在3-5月上旬和下旬以及6、7、10月的中旬测量每株杜鹃的株高和地径,并于6-8月在每个处理中随机选择5株马缨杜鹃测定叶片渗透调节物质(脯氨酸(Pro)、可溶性糖(Ss)、可溶性蛋白(Sp))含量、抗氧化系统(超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性及丙二醛(MDA)含量)指标、光合作用(净光合速率(P_(n))、气孔导度(gs)、胞间CO_(2)浓度(Ci)、蒸腾速率(Tr))指标。研究结果:1)建立了各干旱水平下的马缨杜鹃株高及地径生长响应年序日(DOY)的生长方程,拟合精度0.94-0.99;比较发现田间持水量15%处理下植株死亡率最高;2)建立了各时间段马缨杜鹃株高及地径相对累积生长量随土壤含水量增加而变化的方程,表明株高相对累积增量方程呈单峰曲线变化;但相对地径累积增长量在DOY 161之前随土壤相对含水量增加呈U形变化,DOY 161-201之间呈直线变化,DOY 201以后呈单峰曲线变化。3)随土壤含水量增加,SOD活性、CAT活性、POD活性、P_(n)、gs、Tr及Pro含量整体表现为先增后降,SOD、CAT、POD活性及Pro含量在田间持水量20%-30%达到最大值,P_(n)、gs、Tr在田间持水量60%-80%达到最大值;MDA含量整体表现为逐渐降低;Ci、Ss及Sp含量则呈先降后增的变化趋势,整体表�Aims The Rhododendron as a high ornamental value genus has a great potential for resources development and utilization in China,which provided the most abundant rhododendron resources in the world.The risk of drought stress is rapidly increasing in the context of global warming,but the effects of water stress on growth and physiological and ecological indexes of rhododendrons are still lacking.In this paper,the height and ground diameter growth increment of R.delavayi under the drought stress were studied,and the numerical relationship of the growth increment response to the physiological indicators were established to provide a theoretical basis for the future protection and management of rhododendron.Methods Pots experiment with 2 years old seedlings of R.delavayi were carried out from March 11th to October 15th,2022.The water stress gradient was set as 15%,25%,35%,50%,70%,90%of the field water holding capacity respectively.The height and ground diameter of each R.delavayi were measured in early and late of March,April,May and in the middle of June,July and October.The physiological index of osmotic system(proline(Pro),soluble sugar(Ss),soluble protein(Sp)contents),antioxidant system(superoxide dismutase(SOD),peroxidase(POD),catalase(CAT)activity,malondialdehyde(MDA)content)and photosynthesis system(net photosynthetic rate(P_(n)),stomatal conductance(gs),intercellular CO_(2)concentration(Ci),transpiration rate(Tr))were measured in June,July,and August by randomly selecting five seedlings in each treatment.Important findings 1)The equations of rhododendron height and ground diameter response to the day of year(DOY)were established under each drought gradient with the fitting accuracy between 0.94-0.99.The mortality was the highest under the treatment of 15%of the field water holding capacity.2)The equations of the relative cumulative tree height response to the soil water content were established with the unimodal curve variation.While that of ground diameter response to the soil water content shows the U shape

关 键 词：马缨杜鹃 水分胁迫 生长过程 生理机制 数量关系 

分 类 号：S685.11[农业科学—观赏园艺]