Effects of growth-promoting bacteria on growth, leaf enzyme activity and soil bacterial community of Phyllostachys edulis

Select strains of Enterobacter aerogenes, Bacillus amyloliquefaciens and Acinetobacter calcoaceticus with high phosphorus-solubilizing, potassium-solubilizing and nitrogen-fixing activity. Using ternary quadratic regression orthogonal rotation combination processing, after root irrigation was applied to Phyllostachys edulis seedlings, the plant height, root length, plant height, leaf SPAD value, catalase activity, and soluble sugar content of P. edulis were determined. The optimal combination and rhizosphere and non-rhizosphere soil bacterial community structure were selected for high-throughput sequencing. The results shows that: P. edulis plant height, root length and SPAD value all increased significantly(the maximum treatment group was 30.87%, 29.96%, 7.83% higher than the control group); The CAT activity and soluble sugar content of moso bamboo leaves were also affected by growth-promoting bacteria. The CAT activity and soluble sugar content increased by 266.38% and 1.46% respectively. The interaction effect showed that E. aerogenes and B. amyloliquefaciens were more effective at low application rates(< 40 mL), while the effect of both and A. calcoaceticus was reflected at high application rates(> 40 mL). Alpha and beta analyze showed that growth-promoting bacterial treatment significantly affected the abundance and composition of rhizosphere and non-rhizosphere soil bacterial communities. Bacillus, Paenibacillus and Sphingomonas are the main dominant bacterial genera. The proportion of bacterial abundance in soil samples treated with growth-promoting bacteria was higher than that in the control group. Growth-promoting bacteria can significantly promote the abundance of functional expression related to material metabolism and energy cycle.Growth promoting bacteria can enhance the material circulation and metabolism by changing the rhizosphere soil microbial community structure, and achieve the purpose of promoting plant growth.