Identification and screening of plant growth-promoting rhizobacteria（PGPR）with ability of phosphatesolubilizing or potassium-solubilizing

In order to obtain plant growth-promoting rhizobacteria（ PGPR） strains with efficient activity on solubilizing phosphate or potassium, and the potentiality as fertilizer-producing bacteria, strains were isolated by using selective medium and diluting culture, then they were identified after a series of physiological and biochemical experiments and 16S rDNA sequence analysis. And the solubilization activity was tested, unopposed strains were selected and used as biological bacterial fertilizer. The results showed that b6（ Bacillus megaterium） had efficient activity on solubilizing inorganic phosphorus, b7（ B. mucitaginosus） had efficient activity on solubilizing potassium. Under laboratory conditions, the compound biological fertilizer had a significant promoting effect on Tephrosia candida, but it still couldn’t replace chemical fertilizers. Biological bacterial fertilizer can be used with the reduction of chemical fertilizer, to improve the fertilizer utilization.