冷胁迫对2种垂穗披碱草生长和生理特性的影响  

Effects of Cold Stress on the Growths and Physiological Characteristics of Two Elymus nutans Varieties

作　　者：付娟娟[1] 刘建[1] 孙永芳[1] 褚希彤[1] 苗彦军[2] 呼天明[1] 许岳飞[1] 

机构地区：[1]西北农林科技大学动物科技学院,陕西杨凌712100 [2]西藏农牧学院植物科学学院,西藏林芝860000

出　　处：《草地学报》2014年第4期789-795,共7页Acta Agrestia Sinica

基　　金：西北农林科技大学基本科研业务费专项(QN2011100);国家科技支撑计划(2011BAD17B05)(2011BAC09B03)资助

摘　　要：低温是影响植物生长的外界限制因子之一。采用沙培法研究了冷胁迫对2种垂穗披碱草(Elymus nutans)(当雄垂穗披碱草(西藏野生)和甘南垂穗披碱草)生长与生理特性的影响。结果表明:冷胁迫处理5 d显著抑制2种垂穗披碱草的生长和叶绿素的合成,特别是甘南垂穗披碱草发生严重氧化损伤,电解质渗透率和丙二醛(MDA)含量分别比对照增加114.7%和124.6%,而当雄垂穗披碱草受伤害较轻,分别比对照增加18.2%和10.8%。冷胁迫也显著增加了甘南垂穗披碱草中H_2O_2和自由基的积累,而当雄垂穗披碱草与对照相比差异不显著。冷胁迫处理5 d后,当雄垂穗披碱草的类胡萝卜素含量较甘南增加72.3%,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)的活性分别较对照增加80.3%,27.3%和65.9%;甘南垂穗披碱草的SOD和POD活性分别较对照增加11.4%和28.9%,而其CAT活性下降25.5%。相关分析表明,垂穗披碱草在冷胁迫下细胞膜受损伤程度与抗氧化酶活性负相关。当雄垂穗披碱草通过提高抗氧化酶活性,可有效清除体内积累的活性氧,减轻细胞膜系统受损伤的程度从而提高其抗寒性。Low temperature is one of the limiting factors affecting plant growth.The growths and physiological characteristics of Tibetan wild Elymus nutans and Gannan E.nutans were studied under cold stress with sand culture in this paper.The results showed that cold stress significantly inhibited the seedling growths and chlorophyll syntheses of two E.nutans varieties.Gannan E.nutans leaves were more liable to suffer oxidative damage than the wild E.nutans leaves.The electrolyte leakages and MDA contents of tested varieties increased by 114.7%,124.6% and 18.2%,10.8% comparing to control,respectively.During the period of cold stress,the accumulations of hydrogen peroxide （H2O2） and superoxide radical in E.nutans increased compared with the control.Damxung E.nutans maintained significantly higher carotenoids （Car） content and the activities of antioxidant enzyme,superoxide dismutase （SOD）,catalase （CAT） and peroxidase （POD） were 80.3%,27.3% and 65.9% higher than the control.Correlation analyses indicated there were significant correlations between growth and physiology charaterisitics,as well as lipid peroxidation and antioxidant enzyme activities in E.nutans leaves.It can be concluded that Dangxiong specices exhibits a better tolerance to cold stress than Gannan.

关 键 词：冷胁迫 膜脂过氧化 活性氧 抗氧化酶 垂穗披碱草 

分 类 号：S543.9[农业科学—作物学] Q945.78[生物学—植物学]