南京林业大学学报(自然科学版) ›› 2021, Vol. 45 ›› Issue (6): 99-110.doi: 10.12302/j.issn.1000-2006.202012040

• 研究论文 • 上一篇    下一篇

梭梭根际根瘤菌对紫花苜蓿生长及耐盐性的影响

陈佳(), 缑晶毅, 赵祺, 韩庆庆, 李慧萍, 姚丹, 张金林*()   

  1. 兰州大学草地农业生态系统国家重点实验室,草地微生物研究中心,农业农村部草牧业创新重点实验室,草地农业教育部工程研究中心,兰州大学草地农业科技学院,甘肃 兰州 730000
  • 收稿日期:2020-12-27 接受日期:2021-03-01 出版日期:2021-11-30 发布日期:2021-12-02
  • 通讯作者: 张金林
  • 基金资助:
    国家重点研发计划(2019YFC0507703);国家自然科学基金项目(31222053)

Induced growth and salt tolerance of alfalfa by rhizobium strains from the rhizosphere of Haloxylon ammodendron

CHEN Jia(), GOU Jingyi, ZHAO Qi, HAN Qingqing, LI Huiping, YAO Dan, ZHANG Jinlin*()   

  1. (State Key Laboratory of Grassland Agro-ecosystems,Center for Grassland Microbiome, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, Engineering Research Center of Grassland Industry, Ministry of Education; College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730000, China
  • Received:2020-12-27 Accepted:2021-03-01 Online:2021-11-30 Published:2021-12-02
  • Contact: ZHANG Jinlin

摘要: 目的 土壤盐渍化是降低植物生产力、制约农业发展的主要非生物胁迫因素之一,豆科植物共生固氮菌对土壤盐渍化非常敏感,因此探讨盐胁迫下荒漠植物根际根瘤菌资源对紫花苜蓿生长及耐盐性的影响,有望为豆科植物新型复合微生物菌肥的研发和增强紫花苜蓿(Medicago sativa)耐盐能力提供理论基础和优质菌种资源。方法 以从梭梭(Haloxylon ammodendron)根际分离得到的3株根瘤菌(WAW-10、WA30-5和WM30-21)为研究对象,探究0和300 mmol/L NaCl处理下3株梭梭根际根瘤菌对紫花苜蓿生长和耐盐性的影响。结果 接种3株梭梭根际根瘤菌均促进了正常条件和盐胁迫下紫花苜蓿植株的生长,叶绿素含量、根系活力、含碳量和含氮量均显著提升,尤以菌株WM30-21的综合效果最佳;各接菌处理均可诱导紫花苜蓿结瘤,尤以菌株WM30-21的效果最佳。盐胁迫下,接种3株梭梭根际根瘤菌均提高了紫花苜蓿的过氧化氢酶活性,降低了相对质膜透性和丙二醛含量,从而维持了质膜的相对完整性;并提高了紫花苜蓿叶片可溶性糖和脯氨酸含量,从而增强了渗透调节能力;还降低了紫花苜蓿植株中的Na+含量、维持K+含量的相对稳定,从而提高了钾、钠离子物质量之比(K+/Na+),其中以菌株WM30-21的效果最佳。结论 接种3株梭梭根际根瘤菌均不同程度地促进了紫花苜蓿的生长,并通过维持质膜的相对完整性、增强渗透调节能力和提高K+/Na+来增强其耐盐性,其中以菌株WM30-21效果最佳。

关键词: 梭梭, 根际, 根瘤菌, 紫花苜蓿, 促生作用, 耐盐性

Abstract:

【Objective】Soil salinity is one of major abiotic stress factors that reduce plant productivity and restrict agricultural development. Symbiotic nitrogen fixation of legume-rhizobium is very sensitive to soil salinity. Haloxylon ammodendron is a desert shrub species with high drought and salt tolerance. Therefore, deeply exploring the effects of rhizobium strains from the rhizosphere of H. ammodendron on the growth and salt tolerance of Medicago sativa(alfalfa) would provide theoretical basis and excellent rhizobium resources for developing new compound microbial fertilizers and improving the salt tolerance of alfalfa.【Method】The effects of three rhizobium strains (WAW-10, WA30-5 and WM30-21) isolated from the rhizosphere of H. ammodendron on the growth promotion and salt tolerance of alfalfa were investigated. Sinorhizobium meliloti Sm1021 was used as the reference strain.【Result】Under normal conditions or salt stress (300 mmol/L NaCl), WAW-10, WA30-5 and WM30-21 significantly increased plant height, root length, biomass, leaf chlorophyll content, root activity, and the carbon and nitrogen contents of alfalfa; three strains all induced the nodulation of alfalfa. Under 300 mmol/L NaCl, WAW-10, WA30-5 and WM30-21 significantly improved catalase activity and reduced relative membrane permeability and malondialdehyde content, therefore increased relative membrane integrity; WAW-10, WA30-5 and WM30-21 significantly increased leaf-soluble sugar and proline contents with increased osmotic regulation ability; WAW-10, WA30-5 and WM30-21 significantly decreased Na+ content in the shoots and roots of alfalfa and maintained the relative stability of the K+ content, resulting in an increased tissue K+/Na+ molar ratio (P < 0.05).【Conclusion】The inoculation of three rhizobium strains isolated from the rhizosphere of H. ammodendron all promoted the growth of alfalfa and improved its salt tolerance through maintaining relative membrane integrity, improving osmotic regulation ability and increasing tissue K+/Na+ molar ratio; WM30-21 had the optimal effects.

Key words: Haloxylon ammodendron, rhizosphere, rhizobium, Medicago sativa, growth promotion, salt tolerance

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