垂穗披碱草根际促生菌的分离鉴定及促生作用研究

Screening and Promoting Effects of Plant Growth-Promoting Bacteria from Rhizosphere of Campeiostachys nutans Griseb.

优良的根际生长促生菌(Plant growth-promoting rhizobacteria, PGPR)是生产优质微生物菌肥的重要物质基础。本研究以广布于青藏高原的垂穗披碱草(Campeiostachys nutans Griseb.)为材料,采用平板划线法分离其PGPR,探究菌株的促生特性,通过16S测序确定菌株的分类地位,并进行盆栽试验验证PGPR的促生效果。结果表明,从垂穗披碱草根际土筛选出14株促生特性优良的PGPR,其中,有11株兼具产IAA,ACC脱氨酶以及铁载体的能力。经16S rDNA鉴定,以假单胞菌属为优势菌属,6株属于假单胞菌属(Pseudomonas),2株属于芽孢杆菌属(Bacillus),2株属于葡萄球菌属(Staphylococcus),其他四株分别属于类节杆菌属(Paenarthrobacter)、微杆菌属(Microbacterium)、不动杆菌属(Acinetobacter)和考克氏菌属(Kocuria)。盆栽试验表明,接种14株菌株对多年生黑麦草具有良好的促生效果,并能够提高其光合效率。研究结果丰富了植物根际促生菌菌种资源库,为实现农业“绿色增产”提供优质菌肥种质资源。

The excellent plant growth-promoting rhizobacteria(Plant growth-promoting rhizobacteria,PGPR)serve as a crucial material foundation for the production of high-quality microbial fertilizers.In this study,the streak plate method was employed to isolate PGPR from Campeiostachys nutans Griseb.,which widely distributed in the Qinghai-Tibet Plateau.We investigated the growth promoting characteristics of the isolated strains.Furthermore,the classification status of the strains was determined by 16S sequencing,and the growth promoting effect of PGPR was verified by pot experiment.The results revealed that 14 strains of PGPR with outstanding growth promotion abilities were screened from the rhizosphere soil of C.nutans,in which 11 strains among them exhibited capabilities to produce indole-3-acetic acid(IAA),ACC deaminase,and iron carriers.Based on 16S rDNA identification,Pseudomonas emerged as the dominant strain with six representatives belonging to this genus,two strains belonging to Bacillus and another two strains belonging to Staphylococcus.The remaining four strains were classified as Arthrobacter,Microbacterium,Acinetobacter,and Kocuria genera respectively.A pot experiment demonstrated that inoculation with these 14 strains had a significant positive impact on the growth of Lolium perenne.Moreover,all strains enhanced the photosynthetic efficiency of L.perenne,compared to non-inoculation.The present study enriched the germplasm bank of rhizosphere growth-promoting bacteria,and also provided valuable resources for high-quality bacterial fertilizer germplasm,thus contributing to agricultural sustainable development.