干旱胁迫及复水对裸果木幼苗生理特性的影响  

Effects of drought stress and rehydration on the physiological characteristics of Gymnocarpos przewalskii seedlings

作　　者：王小风 马步东 黄海霞[1] 罗永忠[1] 齐建伟 邓卓 WANG Xiao-feng;MA Bu-dong;HUANG Hai-xia;LUO Yong-zhong;QI Jian-wei;DENG Zhuo(College of Forestry,Gansu Agricultural University,Lanzhou 730070,China)

机构地区：[1]甘肃农业大学林学院,甘肃兰州730070

出　　处：《草业学报》2025年第4期93-103,共11页Acta Prataculturae Sinica

基　　金：国家自然科学基金(32160409);横向合作项目“沙化土地封禁保护区社会经济效益监测”(03723019)资助。

摘　　要：裸果木是亚洲中部荒漠区的特有种,其耐旱耐瘠薄,有较强的抗风固沙能力,是我国重点保护野生植物。本研究以二年生裸果木幼苗为试验材料,设置对照(土壤水分保持在田间持水量的60%~70%)和干旱处理(水分梯度依次设计为田间持水量的40%~50%、30%~40%、20%~30%、10%~20%、5%~10%),开展干旱胁迫及复水试验,测定叶水势、渗透调节物质含量和抗氧化指标,探究干旱胁迫如何影响幼苗叶片的生理特性以及复水后植物的恢复能力,以期为裸果木干旱适应机制的研究及物种保护提供理论依据。结果显示:随干旱胁迫时间的延长,脯氨酸(Pro)、可溶性蛋白(SP)、可溶性糖(SS)、丙二醛(MDA)含量和过氧化物酶(POD)活性均显著上升;超氧化物歧化酶(SOD)活性先上升后下降;过氧化氢酶(CAT)活性、叶水势呈下降趋势。SP含量、SOD和CAT活性在复水第5天时基本恢复至对照水平,其他各指标在复水第10天时基本恢复至对照水平。干旱胁迫下,裸果木幼苗通过主动积累Pro、SP和SS降低渗透势,采取低水势耐受干旱的方式;通过增强SOD和POD酶活性和积累抗坏血酸(AsA)来清除过量的活性氧。复水后,裸果木幼苗具有较强的恢复能力。Gymnocarpos przewalskii is an endemic species in the desert region of central Asia.It is tolerant to drought and barrenness,with a strong ability to reduce wind erosion and stabilize sand.Thus,it is a key wild plant for environmental protection in China.The aim of this work was to determine how drought stress affects the physiological characteristics of the leaves of G.przewalskii seedlings,and to evaluate their ability to recover after rewatering,with a view to exploring its drought adaptation mechanism.In these experiments,2-year-old G.przewalskii seedlings were subjected to drought treatments(soil moisture at 40%-50%,30%-40%,20%-30%,10%-20%,and 5%-10%of field capacity)or control conditions(soil moisture at 60%-70%of field capacity)and then rewatered.The leaf water potential,osmotic regulator content,and antioxidant indexes were determined to investigate its responses to drought and rewatering.The results showed that proline(Pro),soluble protein(SP),soluble sugar(SS),and malondialdehyde contents and peroxidase(POD)activity increased significantly as the duration of the drought treatments extended.Superoxide dismutase(SOD)activity first increased and then decreased,and catalase(CAT)activity and leaf water potential showed a decreasing trend during the drought treatments.The SP content and SOD and CAT activities recovered to levels similar to those in the control at the 5th day after rewatering,and other indexes recovered to levels similar to those in the control at the 10th day after rewatering.Under drought stress,G.przewalskii seedlings reduced their osmotic potential by actively accumulating Pro,SP,and SS,and adopted a drought-tolerant state by maintaining a low water potential.In drought-affected seedlings,reactive oxygen species were effectively scavenged because of increased activities of SOD and POD and the accumulation of ascorbic acid.After rewatering,the G.przewalskii seedlings showed a strong ability to recover.These findings provide new information about the drought adaptation mechanism of G.przewals

关 键 词：裸果木 干旱胁迫 复水 渗透调节物质 抗氧化指标 

分 类 号：S793.9[农业科学—林木遗传育种]