柴胡根际植物促生细菌与丛枝菌根真菌资源的挖掘及协同促生效应

Isolation of plant growth-promoting rhizobacteria and arbuscular mycorrhizal fungi from the rhizosphere of Bupleurum chinense and characterization of their synergistic effects on plant growth

摘要:

目的 根际微生物群落对植株生长发育和品质形成具有重要调控作用。因此，本研究旨在系统分离柴胡(Bupleurum chinense DC.)根际促生微生物资源，评价其应用潜力，为开发微生物菌肥、减少化肥和农药投入提供优良菌株。方法 采用传统分离培养方法，从柴胡根际分离鉴定植物根际促生细菌(plant growth-promoting rhizobacteria, PGPR)和丛枝菌根真菌(arbuscular mycorrhizal fungi, AMF)；通过体外功能试验筛选高效PGPR菌株，并在盆栽条件下评估PGPR和AMF的协同促生效应。结果 从柴胡根际共分离获得25种PGPR，以及摩西管柄囊霉(Funneliformis mosseae)和幼套内养囊霉(Entrophospora etunicata) 2种AMF。PGPR的功能筛选结果表明，抗生素溶杆菌(Lysobacter antibioticus)、德国鸢尾假单胞菌(Pseudomonas germanica)、类棒杆菌红球菌(Rhodococcus corynebacterioides)和地钱甲基杆菌(Methylobacterium marchantiae)分别在吲哚乙酸分泌、有机磷溶解、无机磷溶解和固氮方面表现突出。盆栽试验显示，PGPR和AMF联合接种显著促进柴胡植株生长、生物量积累和养分吸收，其促生效应明显优于单一接种处理。结论 本研究挖掘并鉴定了一些柴胡根际关键促生微生物资源，明确了PGPR和AMF之间的协同促生效应，为柴胡绿色高效栽培提供了可利用的菌剂资源和理论依据。

Abstract:

Objective The rhizosphere microbial community plays a critical role in plant growth, development, and quality formation. Therefore, this study systematically isolated plant growth-promoting microbial resources from the rhizosphere of Bupleurum chinense and evaluated their application potential, aiming to provide excellent strains for the development of microbial fertilizers to reduce the use of chemical fertilizers and pesticides.Methods Plant growth-promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) were isolated and identified from the rhizosphere of B. chinense by the culture-dependent methods. Functional traits of PGPR strains were screened through in vitro assays, and the synergistic growth-promoting effects of PGPR and AMF were subsequently evaluated by a pot experiment.Results A total of 25 PGPR species and 2 AMF species (Funneliformis mosseae and Entrophospora etunicata) were isolated from the rhizosphere of B. chinense. Functional screening of PGPR revealed that Lysobacter antibioticus, Pseudomonas germanica, Rhodococcus corynebacterioides, and Methylobacterium marchantiae exhibited outstanding abilities in indole-3-acetic acid production, organic phosphorus solubilization, inorganic phosphorus solubilization, and nitrogen fixation, respectively. The pot experiment showed that co-inoculation with PGPR and AMF significantly enhanced the plant growth, biomass accumulation, and nutrient uptake of B. chinense, with plant growth-promoting effects markedly greater than single inoculation treatments.Conclusion This study isolated and identified some plant growth-promoting microorganisms from the rhizosphere of B. chinense and demonstrated the synergistic effects between PGPR and AMF, providing valuable microbial resources and theoretical bases for the sustainable cultivation of B. chinense.