山杜英和黧蒴幼苗对干旱胁迫(PEG)的生理响应  

Physiological responses of seedlings of Elaeocarpus sylvestris and Castanopsis fissa to PEG stress

作　　者：陈伟光 薛立[2] 任向荣[2,3] 冯慧芳[2] 史小玲[2] 

机构地区：[1]佛山市国营云勇林场,广东高明528518 [2]华南农业大学林学院,广州510642 [3]乌鲁木齐市农科院试验场,乌鲁木齐830000

出　　处：《生态科学》2009年第5期385-390,共6页Ecological Science

基　　金：广东省林业局科技项目(4400-F07064;4400-F08018)资助

摘　　要：以山杜英(Elaeocarpus sylvestris)和黧蒴(Castanopsis fissa)幼苗为试验材料,利用聚乙二醇6000(PEG-6000)人工模拟水分胁迫环境,设置三个胁迫强度处理(轻度、中度、重度)、三个胁迫持续时间处理(12 h、24 h、36 h),以不加PEG-6000的1/2Hoagland营养液中的苗木作为对照,对2个树种幼苗的叶片相对含水量、相对电导率、脯氨酸含量、叶绿素含量、超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量和可溶性糖含量进行了测定,研究了水分胁迫对这2种幼苗的影响。结果表明:随着水分胁迫强度的加深及持续时间的延长,2种幼苗叶片相对含水量出现下降趋势,黧蒴的含水量下降更为显著;2种树种幼苗叶片内相对电导率呈波动性上升,黧蒴在轻度胁迫时相对电导率有大幅增加;2种幼苗的脯氨酸含量显著增加,叶绿素含量呈小幅波动,SOD活性先升后降,可溶性糖含量呈现波动性上升;山杜英叶片的MDA含量增加较缓慢,而黧蒴叶片的MDA含量大幅度增加。研究表明幼苗山杜英比黧蒴抗旱性强,叶片相对含水量、相对电导率和MDA含量可作为评价这2种苗木抗旱性的依据。A study on the physiological changes of Elaeocarpus sylvestris and Castanopsisfissa seedlings was conducted under drought stress using treatments of different PEG6000 concentration （mild stress, moderate stress, severe stress） and different stress duration （12 hours, 24 hours, 36 hours）, and 1/2Hoagland nutrient solution without PEG6000 was used as control. Resistance of the seedlings to drought stress was evaluated by testing relative water content, relative conductivity, free proline content, chlorophyll content, super oxide dismutase （SOD） activity, malondidehyde （MDA） content and soluble sugar content. The results showed that with increasing stress intensity and prolonging duration, relative water content of the two seedlings decreased, and that of the C. fissa decreased greater than E. sylvestris; their relative conductivities showed a fluctuant increase. Compared to the control, relative conductivity of C. fissa increased more significantly than E. sylvestris; the contents of free proline of two seedlings increased significantly; contents of chlorophyll fluctuated slightly; the activities of SOD increased at the beginning of drought treatment, but decreased later; contents of soluble sugar increased with increasing stress intensity and prolonging duration. The MDA content of E. sylvestris increased slowly, whereas that of C. fissa increased rapidly. The present study indicates that E. sylvestris is more resistant to drought stress than C. fissa, and that relative water content, relative conductivity and MDA content can be as indicators for drought resistance evaluation for the two seedlings.

关 键 词：阔叶苗木 PEG 抗旱 生理 

分 类 号：Q178.532[生物学—水生生物学]