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草业学报 ›› 2021, Vol. 30 ›› Issue (3): 137-157.DOI: 10.11686/cyxb2020416

• 研究论文 • 上一篇    下一篇

混合盐碱胁迫对醉马草种子萌发及幼苗生理特性的影响

陈雅琦(), 苏楷淇, 陈泰祥, 李春杰()   

  1. 兰州大学草地农业生态系统国家重点实验室,兰州大学草地农业农村部草牧业创新重点实验室,兰州大学草地农业教育部工程研究中心,兰州大学草地微生物研究中心,兰州大学甘肃省西部草业技术创新中心,兰州大学草地农业科技学院,甘肃 兰州 730020
  • 收稿日期:2020-09-14 修回日期:2020-10-26 出版日期:2021-03-20 发布日期:2021-03-09
  • 通讯作者: 李春杰
  • 作者简介:Corresponding author. E-mail: chunjie@lzu.edu.cn
    陈雅琦(1995-),女,河北石家庄人,在读硕士。E-mail: chenyq19@lzu.edu.cn
  • 基金资助:
    国家973项目(2014CB138702);长江学者和创新团队发展计划(IRT-17R50);国家自然科学基金(30070546);中央高校基本科研业务费(LZUJBKY-2020-kb10);111引智基地(B12002)

Effects of complex saline-alkali stress on seed germination and seedling physiological characteristics of Achnatherum inebrians

Ya-qi CHEN(), Kai-qi SU, Tai-xiang CHEN, Chun-jie LI()   

  1. State Key Laboratory of Grassland Agro-Ecosystems,College of Pastoral Agricultural Science and Technology,Key Laboratory of Grassland Livestock Industry Innovation,Ministry of Agriculture and Rural Affairs,State Key Laboratory of Engineering Research Center of Grassland Industry,Ministry of Education,Center for Grassland Microbiome,Western China Technology Innovation Center for Grassland Industry,College of Pastoral Agriculture Science and Technology,Lanzhou University,Lanzhou 730020,China
  • Received:2020-09-14 Revised:2020-10-26 Online:2021-03-20 Published:2021-03-09
  • Contact: Chun-jie LI

摘要:

针对西北盐碱地区栽培土壤资源有限问题,研究混合盐碱胁迫对醉马草种子萌发及幼苗生理相关酶特性的影响,旨在探讨与揭示醉马草对盐碱土壤环境的适应机制,为西北盐碱地区的耐盐草种的选育及栽培提供理论基础。为模拟西北地区复杂的盐碱环境,本研究将中性盐(NaCl、Na2SO4)和碱性盐(NaHCO3、Na2CO3)按不同比例混合(A: NaCl∶Na2SO4=1∶1; B: NaCl∶Na2SO4∶ NaHCO3=1∶2∶1; C: NaCl∶Na2SO4∶NaHCO3∶Na2CO3=1∶9∶9∶1; D: NaCl∶Na2SO4∶NaHCO3∶Na2CO3=1∶1∶1∶1; E: NaCl∶Na2SO4∶NaHCO3∶Na2CO3=9∶1∶1∶9),并设置50、100、150、200 mmol·L-14个盐浓度梯度对带菌(E+)和不带菌(E-)醉马草种子萌发和幼苗生长阶段进行胁迫,分析盐胁迫下醉马草种子萌发阶段的发芽率、发芽势、发芽指数、活力指数、平均发芽时间及幼苗生长阶段的苗长、胚根长度、根冠比、抗氧化酶(POD、SOD、CAT)活性、丙二醛 (MDA)和脯氨酸(proline)含量。并通过隶属函数和主成分分析对不同盐胁迫下的醉马草耐盐性进行综合评价。结果表明:5种盐碱胁迫均使醉马草发芽率、发芽势、发芽指数、活力指数降低及平均发芽时间延长,且随盐浓度的增加,种子萌发受到显著抑制(P<0.05);盐碱胁迫亦随盐浓度的增加使醉马草胚根长度、根冠比显著降低。除C、E处理外,其余混合盐碱胁迫下的醉马草幼苗生理指标(POD、SOD、MDA、proline)均随盐浓度的上升而下降。隶属函数和主成分分析显示不同混合盐碱胁迫下的醉马草耐盐性大小顺序为A>D>B>C>E。综上可知,盐碱胁迫显著抑制醉马草种子萌发和幼苗生长(P<0.05),其中碱性盐(NaHCO3、Na2CO3),尤以Na2CO3对醉马草种子萌发和幼苗生长抑制作用强于中性盐。活力指数、胚根长度、POD、SOD、proline为评价醉马草耐盐性的主要指标。E+醉马草耐盐性优于E-,内生真菌可有效提高醉马草渗透调节和活性氧清除能力,降低膜脂过氧化作用,提高醉马草耐盐性。

关键词: 混合盐碱胁迫, 醉马草, 内生真菌, 生理特性, 耐盐性

Abstract:

Saline-alkali land currently has limited options for cultivation and development. This project investigated seed germination, physiological characteristics and antioxidant enzyme activities of Achnatherum inebrians in order to better understand the adaptation to saline soil environments exhibited by this species and provide information to aid future breeding selection and cultivation. A set of 20 different alkali-saline stress conditions were stimulated by mixing two neutral (NaCl and Na2SO4) and two alkaline (NaHCO3 and Na2CO3) salts with soil in different proportions (A: NaCl∶Na2SO4=1∶1; B: NaCl∶Na2SO4∶NaHCO3=1∶2∶1; C: NaCl∶Na2SO4∶NaHCO3∶Na2CO3=1∶9∶9∶1; D: NaCl∶Na2SO4∶NaHCO3∶Na2CO3=1∶1∶1∶1; E: NaCl∶Na2SO4∶NaHCO3∶Na2CO3 = 9∶1∶1∶9) and at concentrations of 50, 100, 150, and 200 mmol·L-1. These soil mixtures were used to grow seedlings of endophyte-infected (E+) and endophyte-free (E-) drunken horse grass, and analyze the general salt tolerance of drunken horse grass accessions at the germination and seedling growth stages were analyzed. The seed germination rate, germination vigor, germination index, energy index and shoot length, root length, root-shoot ratio, and shoot tissue antioxidant enzymes peroxidase (POD) and superoxide dismutase (SOD), malondialdehyde (MDA) and proline were evaluated and analyzed data explored by subordinate function analysis. It was found that the germination rate, germination potential, germination index and vigor index of both E+ and E- drunken horse grass were decreased under the five different saline-alkali stresses. Germination was significantly inhibited with increase in saline-alkali stress concentration (P<0.05). The radicle length and root-shoot ratio were also significantly decreased with increased salt concentration. Except for treatments C and E, physiological indexes (POD, SOD and CAT activities, MDA and proline levels in shoot tissue) of drunken horse grass were reduced at higher salt concentrations. Subordinate function analysis and the multivariate analysis of salt tolerance indicated that the order of salt tolerance across treatments was A>D>B>C>E. In conclusion, saline-alkali stress significantly inhibited seed germination and seedling growth of drunken horse grass (P<0.05). Among the alkaline salts tested (NaHCO3 and Na2CO3), Na2CO3, especially, had a stronger inhibitory effect on seed germination and growth. Vigor index, root length, POD, SOD, and proline were found to be the most useful indicators to evaluate the salt tolerance of drunken horse grass. The salt tolerance of E+ drunken horse grass was found to be better than that of E-. Epichlo? endophytic fungi can improve the osmotic adjustment and scavenging of reactive oxygen species of drunken horse grass, thus reducing the membrane lipid peroxidation, and improving the salt tolerance of A. inebrians.

Key words: mixed saline-alkali stress, drunken horse grass, endophytic fungi, physiological property, salt tolerance