白三叶根际产铁载体菌的分离及促生特性研究

Isolation and Growth-promoting Characteristics of Siderophore-producing Bacteria in Rhizosphere of Trifolium repens

【目的】挖掘贵州省内野生牧草根际产铁载体菌资源,为植物根际促生菌的进一步开发利用提供菌种资源,为解决植物缺铁症促进植物抗逆增产提供依据。【方法】采用土壤稀释法对白三叶根际产铁载体菌进行分离,利用定性、定量分析对其产铁载体能力进行测定,通过16S rRNA基因序列鉴定菌株,并对菌株促生特性进行检测。【结果】从贵州黔南、贵阳、铜仁地区3份白三叶根际土壤中分离得到产铁载体菌5株(TSQD-1、TSQD-2、TSGH-1、TSTY-1、TSTY-2),均属于假单胞菌属(Pseudomonas sp.),其中,菌株TSGH-1、TSQD-1和TSQD-2有较强的产铁载体能力;5个菌株均具有溶解无机磷、固氮和分泌IAA能力,其中,TSGH-1有较强的溶解无机磷能力和较高的固氮酶活性,TSTY-2具有较高的产IAA能力。【结论】贵州白三叶根际土壤产铁载体菌株均属假单胞菌属(Pseudomonas sp.),TSGH-1、TSQD-1和TSQD-2菌株同时具有溶磷、固氮和分泌IAA能力,具有多重促生特性。

【Objective】The resources of the siderophore-producing bacteria in the rhizosphere of wild forages in Guizhou Province were explored,which provided the bacterial resource for the further development and utilization of plant root-promoting rhizobacteria,and provided the reference for solving Fe deficiency in plants and promoting the yield improvement and stress resistance of plants.【Method】The siderophore-producing bacteria in the rhizosphere of Trifolium repens were isolated by the soil dilution method,and the ability to secrete siderophore was determined through qualitative and quantitative analysis,and then the strains were identified based on 16S rRNA gene sequence,finally the growthpromoting characteristics of the strains were detected.【Result】Five strains of siderophore-producing bacteria(TSQD-1,TSQD-2,TSGH-1,TSTY-1,TSTY-2)were isolated from the rhizosphere of three T.repens samples from Qiannan,Guiyang and Tongren area of Guizhou Province,and all of them were identified as Pseudomonas sp..The TSGH-1,TSQD-1 and TSQD-2 strains had high siderophore production ability.All five strains had the ability of dissolving inorganic phosphorus,fixing nitrogen,and secreting IAA,among them,TSGH-1 had strong ability of dissolving inorganic phosphorus and high nitrogenase activity,while TSTY-2 had high IAA production ability.【Conclusion】The siderophore-producing bacteria in the rhizosphere of T.repens belonged to Pseudomonas sp..The TSGH-1,TSQD-1,and TSQD-2 strains had the ability of dissolving inorganic phosphorus,fixing nitrogen,and secreting IAA,which had the multiple growth-promoting characteristics.