模拟干旱胁迫下鹰嘴紫云英幼苗生长及生理特性  

The Growth and Physiological Characteristics of Astragalus cicer L.Seedlings under Simulated Drought Stress

作　　者：戴海根 董文科[1] 柴澍杰 马晖玲[1] DAI Hai-gen;DONG Wen-ke;CHAI Shu-jie;MA Hui-ling(College of Grassland Science,Gansu Agricultural University/Key Laboratory of Grassland Ecosystem,Ministry of Education/Pratacultural Engineering Laboratory of Gansu Province/Sino-US Centers for Grazingland Ecosystem Sustainability,Lanzhou 730070,China)

机构地区：[1]甘肃农业大学草业学院/草业生态系统教育部重点实验室/甘肃省草业工程实验室/中-美草地畜牧业可持续发展研究中心,甘肃兰州730070

出　　处：《中国草地学报》2021年第10期63-75,共13页Chinese Journal of Grassland

基　　金：国家自然科学基金项目(31760699)资助。

摘　　要：为探明鹰嘴紫云英(Astragalus cicer L.)幼苗期应对干旱胁迫的生长响应特征,采用聚乙二醇(PEG)溶液模拟干旱胁迫,试验共设置4个处理水平(对照、轻度、中度和重度胁迫,PEG浓度分别为0%、10%、20%和30%),分析不同胁迫时间(0、2、4、6、8和10d)鹰嘴紫云英形态特征及生理特性的变化。结果显示,轻度胁迫下,株高、根长在胁迫前期显著增加,可溶性糖含量显著提升,蒸腾速率明显下降。中度胁迫下,叶片、根系相对含水量、根系总表面积、光合参数等均有所下降,可溶性蛋白含量显著升高,第10d较对照增加21.5%,抗氧化酶活性明显上升,其中过氧化氢酶活性于第8d升高最为明显,较对照增加85.7%;重度胁迫下,可溶性糖和脯氨酸含量显著上升,第8d较对照分别增加151.1%和4350.0%,抗氧化酶活性先升后降,形态指标、光合参数均显著下降。干旱胁迫下各指标间均存在一定程度相关性,而对抗旱能力影响最大的是膜脂过氧化、形态特征、抗氧化酶因子,可作为苗期抗旱性的鉴定指标。综上所述,鹰嘴紫云英对轻度和中度干旱胁迫具有较强耐受性,可利用形态变化、物质代谢及生理调节等多种机制来适应干旱胁迫环境,而对重度胁迫耐受性较差,其膜脂过氧化程度明显上升,细胞受损严重,生长受到明显抑制。In this study,polyethylene glycol(PEG)solution was used to simulate drought stress to explore the growth response characteristics of Astragalus cicer L.to drought stress at seedling stage.Different stress levels(control,mild,moderate and severe stress with PEG concentrations of 0%,10%,20%and 30%,respectively)were set up to analyze the changes of morphological and physiological characteristics of A.cicer L.with different stress durations(0,2,4,6,8 and 10 days).The result showed that under mild stress,plant height and root length were significantly increased in the early stages of stress,soluble sugar content and transpiration rate were significantly increased and decreased,respectively.Under moderate stress,the relative water content of leaves and roots,total root surface area and photosynthetic parameters exhibited decreasing trend,while antioxidant enzyme activities(increased by 21.5%compared to the control on the 10 th day)and soluble protein content(catalase,85.7%higher than the control on the 8 th day)were significantly increased.Under severe stress,the content of soluble sugar and proline were increased by 151.1%and 4350.0%,respectively,compared with the control on the 8 th day.Moreover,antioxidant enzyme activities increased first and then decreased,and the morphological indexes and photosynthetic parameters significantly decreased.Under drought stress,the indexes indicating drought resistance included membrane lipid peroxidation,morphological characteristics,and antioxidant enzymes,which can be used as indicators of drought resistance at seedling stage.In conclusion,A.cicer L.had strong tolerance to mild and moderate stress,which can adapt to drought stress characterized by morphological changes,substance metabolism and physiological regulation.However,A.cicer L.had inadequate tolerance to severe drought stress,which can cause significant increase in membrane lipid peroxidation,severe cell damage,and growth inhibition.

关 键 词：鹰嘴紫云英 干旱胁迫 形态特征 生理特性 

分 类 号：Q945.78[生物学—植物学]