Analysis of Blueberry Plant Rhizosphere Bacterial Diversity and Selection of Plant Growth Promoting Rhizobacteria

Microbial metabolites in rhizosphere soil are important to plant growth. In this study, microbial diversity in blueberry plant rhizosphere soil was characterized using high-throughput amplicon sequencing technology. There were 11 bacterial phyla and three fungal phyla dominating in the soil. In addition, inorganic-phosphate-solubilizing bacteria (iPSB) in the rhizosphere soil were isolated and evaluated by molybdenum-antimony anti-coloration method. Their silicate solubilizing, auxin production, and nitrogen fixation capabilities were also determined. Eighteen iPSB in the rhizosphere soil strains were isolated and identified as Buttiauxella, Paraburkholderia and Pseudomonas. The higher phosphorus-solubilizing capacity and auxin production in blueberry rhizosphere belonged to genus Buttiauxella sp. The strains belong to genus Paraburkholderia had the same function of dissolving both phosphorus and producing auxin, as well as silicate and nitrogen fixation. The blueberry seeds incubated with the strains had higher germination rates. The results of this study could be helpful in developing the plant growth-promoting rhizobacteria (PGPR) method for enhancing soil nutrients to blueberry plant.