Inoculations withPseudomonas fluorescensandBacillus cereusaffect the soil enzyme activity, growth and rhizosphere microbial diversity ofTaxus chinensisvar.mairei

Background and aims Taxus chinensisvar.maireiis a rare tree endemic to China.Pseudomonas fluorescensCLW17 andBacillus cereusCLY07 were isolated from theT. chinensisvar.maireirhizosphere and the two strains were efficient phosphate-solubilizing bacteria. We investigated the effect of inoculation withP. fluorescensCLW17 andB. cereusCLY07 on soil enzyme activity, growth and the rhizosphere microbial diversity ofTaxus chinensisvar.maireiover different time periods. Methods The plant biomass, seedling height, stem diameter and root vitality were measured, so that the inoculation effects of the two bacterial strains onT. chinensisvar.maireiseedlings could be evaluated. Three types of soil enzymes (alkaline phosphatase, invertase and dehydrogenase) were identified. The soil microbial community composition and diversity were determined by high-throughput pyrosequencing analysis. Results Inoculation withP. fluorescensCLW17 andB. cereusCLY07 significantly increased plant biomass, seedling height, stem diameter and root vitality, and improved soil enzyme activities (alkaline phosphatase, invertase and dehydrogenase) (P < 0.05) inT. chinensisvar.mairei. High-throughput pyrosequencing of 16S and 18S rRNA genes revealed minor changes in the diversity, relative abundance, and composition of the microbial community in theT. chinensisvar.maireirhizosphere after inoculation. Conclusion Inoculation withP. fluorescensCLW17 andB. cereusCLY07 promotedT. chinensisvar.maireigrowth and improved the soil enzyme activity with a small change in rhizosphere microbial diversity. This study provides necessary insight for developing effective, cheap and safe inoculants of strainsP. fluorescensCLW17 andB. cereusCLY07 forT. chinensisvar.mairei.