Isolation and Identification of PGPR Strains from Rhizosphere Soil of Yunnan Flue-cured Tobacco

To improve the quality of tobacco-planting soil, the utilization rate of fertilizer and finally the quality of tobacco in Yunnan Province by local PGPR, rhizosphere soil samples were collected from the main tobacco-planting fields of Yunnan Province. Rhizosphere bacteria were isolated, screened and identified from soil samples. Capacity of potassium-dissolving, phosphate solubilizing and IAA secreting of bacteria were focused. Morphological observation, biochemical analysis and 16s rDNA sequencing were used to identify the species of PGPR candidates. In result, 31 samples of rhizosphere soil were collected from cities of Yuxi, Kunming, Qujing, Honghe, Chuxiong, Dali, and 773 strains of PGPR were isolated from these soil samples. Ten effective strains were obtained after further screening. The strains belongs to Bacillus, Paenibacillus and Providencia. This research provides resource of excellent PGPR strains for further development of microbial fertilizer. Further works will focus on the mixture and colonization research of these PGPR candidates.