Abstract:

To investigate the growth-promoting effects and mechanisms of Bacillus amyloliquefaciens K103 on cucumber plug seedlings，K103 was inoculated into the substrate before sowing，and the growth parameters，mineral elements aborptions were measured. The rhizosphere bacterial diversities were also detected by 454 pyro sequencing. The results showed that K103 showed high nitrogen fixation and phosphorus solubilization capacity. K103 inoculation in substrate could promote the growth and development of cucumber plug seedlings by increasing the mineral absorption and root vigor. The 454 sequencing data suggested that K103 could colonize in the rhizosphere，and increase the relative abundances of nine bacteria species，including Bdellovibrio bacteriovorus，Sphingomonas sp. CHNTR37 and CL01，Acidovorax delafieldii，Mesorhizobium ciceri，etc. Most of these species were plant growth- promoting bacteria.

Key words: cucumber, Bacillus amyloliquefaciens K103, plug seedling, growth-promoting, rhizosphere