锰胁迫对黄花草种子萌发及幼苗生理生化特征的影响  

Effects of manganese stress on seed germination, and seedling physiological and biochemical characteristics of Cleome viscosa

作　　者：肖泽华 李欣航 潘高[1] 吴耀文 杨灿鑫 匡雪韶 刘文胜[1,2] XIAO Ze-hua;LI Xin-hang;PAN Gao;WU Yao-wen;YANG Can-xin;KUANG Xue-shao;LIU Wen-sheng(College of Life Science and Technology,Central-South University of Forestry&Technology,Changsha 410004,China;Hunan Research Center of Engineering Technology for Utilization of Environmental and Resources Plant,Central South University of Forestry and Technology,Changsha 410004,China)

机构地区：[1]中南林业科技大学生命科学与技术学院,湖南长沙410004 [2]湖南省环境资源植物开发与利用工程技术研究中心,湖南长沙410004

出　　处：《草业学报》2019年第12期75-84,共10页Acta Prataculturae Sinica

基　　金：湖南省重点研发计划(2016NK2148);湖南省大学生研究性学习和创新性实验计划项目资助

摘　　要：为探明锰胁迫下黄花草的抗性生理适应机制,以该植物种子为试验材料,研究了不同浓度锰(0,1000,5000,10000,15000和20000μmol·L^-1)胁迫对黄花草种子萌发、幼苗生长的影响及胁迫7、15、30 d生理生化特征的变化。结果表明:1)随着锰浓度的增加,黄花草种子的发芽势、发芽率、发芽指数和活力指数均呈下降趋势;幼苗芽长、根长、生物量和根冠比则先增加后下降,呈现出“低促高抑”现象;2)1000~5000μmol·L^-1锰处理增加了黄花草幼苗叶片叶绿素a、叶绿素b、叶绿素a+b含量和叶绿素a/b值;当浓度继续增加且胁迫时间延长时,叶绿素含量和叶绿素a/b值降低;3)在胁迫第7天,黄花草叶片超氧化物歧化酶(SOD)活性随锰浓度增加逐渐下降,过氧化物酶(POD)和过氧化氢酶(CAT)活性随锰浓度增加呈上升趋势;在胁迫第30天,SOD和POD活性均显著下降,CAT活性无明显下降;4)黄花草幼苗叶片中脯氨酸、可溶性蛋白和可溶性糖含量在胁迫第7、15天随锰浓度增加而增加,在胁迫30 d后则均下降;5)丙二醛(MDA)含量随着锰浓度的增加和胁迫时间的延长而显著增加。研究结果表明,1000~5000μmol·L^-1锰处理会促进黄花草幼苗的生长;该植物可以通过不同抗氧化酶差异化响应及渗透调节物质含量的提高,减轻高浓度锰胁迫所造成的损伤,提高对锰的耐性。In order to investigate the resistance and physiological adaption mechanisms of Cleome viscosa to manganese(Mn)stress,the effects of different concentrations of Mn^2+(0,1000,5000,10000,15000 and 20000μmol·L^-1)on seed germination,seedling growth and the changes in physiological and biochemical characteristics of C.viscosa after 7,15 and 30 days of stress,were assessed.The results showed that:1)With the increasing Mn^2+concentration,the germination potential,germination rate,germination index and vigor index of C.viscosa declined,although the seedling growth was increased at the 1000 and 5000μmol·L^-1 Mn^2+concentrations,displaying a phenomenon of“low to promote and high inhibition”.2)Compared with the control,chlorophyll a,chlorophyll b,chlorophyll a+b content and the ratio of chlorophyll a∶b increased at the Mn^2+concentrations of 1000 and 5000μmol·L^-1,while the chlorophyll content and the ratio of chlorophyll a∶b decreased with rising of Mn^2+concentration above 5000μmol·L^-1 and with exposure time.3)Under Mn^2+stress at day 7,superoxide dismutase(SOD)activity decreased with rising Mn^2+concentration,while the activities of peroxidase(POD)and catalase(CAT)increased;Under Mn^2+stress at day 30,the activities of SOD and POD decreased,while the activity of CAT didn’t decline.4)Proline,soluble protein and soluble sugar of seedlings increased significantly with rising Mn^2+concentration at day 7 and day 15 of exposure,but had decreased after 30 days of stress.5)Malondialdehyde content increased significantly with increasing of Mn^2+concentration and exposure time.In summary,the results showed that exposure to Mn^2+concentrations of 1000 and 5000μmol·L^-1 promoted seedling growth of C.viscosa,and at higher Mn^2+concentrations this plant species can adjust its antioxidant system and enhance its osmotic adjustment to alleviate the damage caused by high Mn stress,thus imparting C.viscosa with a measure of Mn tolerance.

关 键 词：锰胁迫 黄花草 种子萌发 抗氧化系统 渗透调节 

分 类 号：S51[农业科学—作物学]