外源褪黑素对NaCl胁迫下老芒麦种子萌发和幼苗生长的影响  

Effects of exogenous melatonin on seed germination and seedling growth of Elymus sibiricus under NaCl stress

作　　者：苏晓丽 舒欣 王晓耘 熊艳丽 熊毅 刘伟[1] 马啸[1] SU Xiaoli;SHU Xin;WANG Xiaoyun;XIONG Yanli;XIONG Yi;LIU Wei;MA Xiao(College of Grass Science and Technology,Sichuan Agriculture University,Chengdu 611130,Sichuan,China)

机构地区：[1]四川农业大学草业科技学院,四川成都611130

出　　处：《草业科学》2023年第10期2595-2606,共12页Pratacultural Science

基　　金：四川省肉牛和牧草产业体系创新团队项目(SCCXTD-20-13)。

摘　　要：为探究外源添加褪黑素(MT)对NaCl胁迫下老芒麦(Elymus sibiricus)的缓解效应,并筛选出促进老芒麦种子萌发和幼苗生长的最佳MT浓度,以国审品种‘雅江’老芒麦为供试材料,研究不同浓度外源MT(50、100、300、500、800、1000μmol·L^(–1))处理对NaCl胁迫(100 mmol·L^(–1))下老芒麦种子萌发率及其幼苗生长形态和生理特性的影响。结果表明:外源添加不同浓度的MT均能减缓盐胁迫对老芒麦造成的抑制作用,且综合评价分析表明,外源添加100μmol·L^(–1)MT的效果最佳,此处理下老芒麦种子的发芽率、发芽势、发芽指数和活力指数分别较NaCl胁迫下提高了12.7%、61.3%、37.3%和75.0%,幼苗的根冠比提高了59.9%,过氧化物酶(POD)活性和可溶性蛋白含量分别增加了75.1%和153.4%,而丙二醛(MDA)含量降低了29.3%。这表明在盐胁迫环境下,外源MT处理能增强老芒麦的抗氧化酶活性,并清除体内过量的活性氧(ROS),抑制细胞膜质过氧化,以此提高老芒麦幼苗的耐盐性。本研究结果可为建立和优化‘雅江’老芒麦在盐碱环境下的栽培提供理论依据。To explore the alleviation effect of exogenous melatonin(MT)on Elymus sibiricus under NaCl stress and screen out the optimal MT concentration to promote seed germination and seedling growth of E.sibiricus.In this experiment,the national variety‘Yajiang’E.sibiricus was used as the test material to study the effects of concentrations of exogenous MT(50,100,300,500,800,and 1000μmol·L^(-1))on seed germination rate and seedling growth morphology and physiological characteristics of E.sibiricus under NaCl stress(100 mmol·L^(-1)).The results showed that the exogenous addition of concentrations of MT was able to alleviate the inhibitory effect of NaCl stress on E.sibiricus,and the comprehensive evaluation analysis showed that the exogenous addition of 100μmol·L^(-1)of MT had the best effect.Under this treatment,the germination rate,germination potential,germination index,and vigor index of E.sibiricus seeds were 12.7%,61.3%,37.3%,and 75.0%,respectively,higher than those with NaCl stress without addition.The root/shoot ratio of seedlings increased by 59.9%,and the peroxidase activity and soluble protein content increased by 75.1%and 153.4%,respectively.The malondialdehyde content decreased by 29.3%.These results indicateindicates that under NaCl stress,exogenous MT can enhance the antioxidant enzyme activity of E.sibiricus,remove excessive reactive oxygen species,and inhibit membrane lipid peroxidation,improving the NaCl tolerance of E.sibiricus seedlings.The results of this study provide a theoretical basis for establishing and optimizing the cultivation of‘Yajiang’E.sibiricus in a saline-alkali environment.

关 键 词：老芒麦 褪黑素 NACL胁迫 种子萌发 生理特性 渗透调节 抗氧化酶活性 

分 类 号：S543.9[农业科学—作物学]