Isolation and Molecular Characterization of Plant-Growth-Promoting Bacteria and Their Effect on Eggplant (Solanum melongena) Growth

In recent years, the optimum development of land resources has become an important task for ensuring the security of food production in China. Soil microorganisms have been considered to play an important role in conferring soil fertility and productivity. In order to obtain the plant-growth-promoting bacteria in newly reclaimed land, a total of 988 bacterial strains were isolated from nine soil samples collected from different sites in wastelands in Hangzhou (Zhejiang Province, China), a rural mountainous area. Among them, five strains exhibited substantial potential of phosphate solubilization, nitrogen fixation, siderophore production and indole acetic acid production at both pH 5.0 and pH 7.0, and also promoted eggplant growth in immature soil from newly reclaimed land. Furthermore, bacterial strains ZJ62 and ZJ3-12 were identified as Pantoea dispersa and Pantoea ananatis, respectively, while strains ZJ5, ZJ9 and ZJ174 were identified as Burkholderia arboris, Burkholderia pyrrocinia and Burkholderia pyrrocinia, respectively, based on colony morphology observation and phylogenetic analysis of 16S rDNA and the housekeeping genes sequences. Overall, the result of this study showed that the 5 obtained bacterial strains have a great potential in promoting plant growth in immature soil from newly reclaimed land.