稻田土壤固氮菌株的分离筛选及促生潜力  

Isolation,Screening and Plant Growth-promoting Potential of Nitrogen-fixing Strains from Paddy Soils

作　　者：靳海洋 王慧 张燕辉 胡天龙 林志斌[1,2] 刘本娟 蔺兴武 谢祖彬[1] JIN Hai-yang;WANG Hui;ZHANG Yan-hui;HU Tian-long;LIN Zhi-bin;LIU Ben-juan;LIN Xing-wu;XIE Zu-bin(State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008;University of Chinese Academy of Sciences,Beijing 100049)

机构地区：[1]土壤与农业可持续发展国家重点实验室(中国科学院南京土壤研究所),南京210008 [2]中国科学院大学,北京100049

出　　处：《生物技术通报》2020年第6期73-82,共10页Biotechnology Bulletin

基　　金：国家科技基础性工作专项(2015FY110700);国家自然科学基金项目(31870500,41501273)。

摘　　要：旨为获取高效固氮菌株,为稻田生物固氮能力的微生物调控提供菌种资源。选用4个具有不同固氮效率水平的水稻土样品,采用稀释平板法和富集纯化法从土壤中分离可培养固氮菌株,通过基因组DNA的nifH基因扩增、乙炔还原活性的定量测定和无氮培养基上的生长状况筛选优势固氮菌株,进一步对优势固氮菌株进行促生潜力测定。共分离纯化得到可培养微生物菌株14株,以新分离菌株的基因组DNA为模板,有7株菌株能够扩增出nifH基因。其中,新分离菌株P204、P205、P207和P208在无氮培养基上生长速度较快,乙炔还原活性较高,同时具有IAA生成、溶磷活性和铁载体生成等促进植物生长的潜力,可用于进一步功能基因开发和微生物接种应用研究。The aim of this study is to obtain efficient nitrogen-fixing strains and provide microbial resources for microbial regulations of biological nitrogen fixation in paddy fields.Four paddy soil samples with different nitrogen-fixing capability were selected to isolate cultivable nitrogen-fixing strains via serial dilution-plating method and enrichment procedure.Screening efficient nitrogen-fixing strains was performed by nifH gene PCR amplification,acetylene reduction activity and growth on N-free medium.Furthermore,the plant growth-promoting potentials of the efficient nitrogen-fixing strains were determined.A total of 14 cultivable microbial strains were obtained through isolation and purification.The presence of nifH gene was detected from genomic DNA of 7 newly isolated strains.Among them,the newly isolated strain P204,P205,P207 and P208 grew relatively fast and were in high acetylene reduction activity on N-free medium.Moreover,they had the plant growthpromoting potential,such as IAA production,phosphate solubilization and siderophore production.Thus,the newly isolated strains P204,P205,P207 and P208 represent potentially excellent bioresources for the future exploitation of functional genes and microbial inoculants.

关 键 词：土壤 生物固氮 促生菌 微生物资源 

分 类 号：S154.3[农业科学—土壤学]