高羊茅根际耐旱促生菌的分离鉴定及其促生作用  

Isolation and identification of drought-tolerant plant growth-promoting rhizobacteria from tall fescue and their growth-promoting effects

作　　者：胡桑源 李光裕 鲁泽宇 玉苏普喀迪尔·孜米尼 朱天奇 黄轶男 刘铁芫 许岳飞 HU Sangyuan;LI Guangyu;LU Zeyu;Yusupukadier·Zimini;ZHU Tianqi;HUANG Yi’nan;LIU Tieyuan;XU Yuefei(College of Grassland Agriculture,Northwest A&F University,Yangling 712100,Shaanxi,China)

机构地区：[1]西北农林科技大学草业与草原学院,陕西杨凌712100

出　　处：《草业科学》2024年第11期2576-2593,共18页Pratacultural Science

基　　金：陕西省重点研发计划一般项目(2023-YBNY-113);国家自然科学基金项目(32071888);青年科学基金项目(32101443)。

摘　　要：本研究从干旱处理的高羊茅(Festuca arundinacea)根际土壤中分离具有耐旱和促生性能的根际微生物,并结合植物接种试验探究其促生特性,为增强草坪草耐旱性提供优质菌种资源和理论基础。通过平板稀释法从其根际分离纯化出24株细菌,结合形态特征和16S rRNA序列分析对分离菌株进行鉴定,并对其进行促生性能鉴定和聚乙二醇6000(EG-6000)耐受性评价,在此基础上筛选出2株兼具有溶磷、解钾能力以及良好的PEG-6000耐受性的根际促生菌(PGPR)印度克雷伯氏菌(Klebsiella indica)和弗氏志贺氏菌(Shigella flexneri)进行盆栽接种试验。接种结果表明,这两种促生菌能够促进干旱胁迫下高羊茅幼苗的生长,两种菌株1∶1混合后具有更好的促生效果;接种处理能够降低高羊茅品种‘宇宙星’的离体叶片失水率。在干旱胁迫下,印度克雷伯氏菌具有提高高羊茅幼苗脯氨酸含量的能力;而菌株弗氏志贺氏菌具有提高高羊茅种子发芽率且降低高羊茅电解质相对外渗率的能力。研究结果表明,两株根际促生菌有较好的耐旱促生性能,为进一步应用根际促生菌研制高效草坪草专用微生物菌肥提供了菌种资源。Rhizobacteria with drought tolerance and growth-promoting effects were isolated from the rhizosphere soil of drought-treated tall fescue(Festuca arundinacea),and their growth-promoting effects were investigated in combination with plant inoculation experiments to provide high-quality bacterial resources and theoretical basis for the enhancement of drought tolerance of turfgrass.A total of 24 strains of bacteria were isolated and purified from the rhizosphere using the plate dilution method,identified by combining morphological characteristics and 16S rRNA sequence analysis and evaluated for their growth-promoting effects and polyethylene glycol-6000(PEG-6000)tolerance;two strains were screened for their ability to dissolve phosphorus and potassium,and good PEG-6000 resistance.On this basis,two plant growth-promoting rhizobacteria,Klebsiella indica and Shigella flexneri,with both phosphorus solubilizing and potassium solubilizing abilities as well as good PEG-6000 tolerance were screened and inoculated in pots.The results of the inoculation demonstrated that these two biotrophic bacteria were able to promote the growth of tall fescue seedlings under drought stress,and the 1꞉1 mixture of the two strains had a better growth-promoting effect;meanwhile,the inoculation treatment was able to reduce the water loss rate of isolated leaves of tall fescue cultivar‘Acending Star’.In addition,strain K.indica had the ability to increase the proline content of tall fescue seedlings under drought stress,while strain S.flexneri had the ability to increase the germination rate of tall fescue seeds and was able to reduce the relative exudation rate of electrolytes in tall fescue.The results indicated that K.indica and S.flexneri had better drought tolerance and provided strain resources for further application of the inter-root biotrophic bacteria in the development of efficient microbial fertilizers for turfgrass.

关 键 词：高羊茅 干旱 根际促生菌 溶磷 解钾 PEG耐受性 促生效应 

分 类 号：S688.4[农业科学—观赏园艺]