Study On The Bacterial Community Diversity Of The Root Domain Of Tree Peony Based On Culture-independent Approach

Bacterial community diversity of root domains of tree peony in two areas ( Shanghai and Luoyang ) in two varieties ('Fengdan'and'Lan Furong') in two seasons ( Summer and Winter ) was studied by the cultured-independent method of constructing 16S rDNA clone libraries.The soil total DNA of tree peony root domains was extracted by five methods. Comparing to the DNA concentration and purity and PCR amplification, the DNA extraction method of Mobio's kit was determined to extract soil DNA of tree peony root domains.Bacterial community diversity of root domains of tree peony in two areas was respectively investigated. The results showed the diversity of uncultured bacteria was abundant in the root domains of tree peony in different areas, and relatively low in the rhizoplane of tree peony. The dominant group was Proteobacteria in all sam-ples of root domains of tree peony.Investigating respectively bacterial community diversity of root domains of'Fengdan'and'Lan Furong', the results showed that obvious differences existed among bacterial community diversity of root domains of tree peony, large in the rhizosphere. And the diversity was higher in root domains of'Lan Furong'in Shanghai than'Fengdan'in Shanghai, higher in root domains of'Fengdan'in Luoy-ang than'Lan Furong'in Luoyang.Bacterial community diversity of root domains of tree peony in different sea-sons was respectively investigated. The obvious differences existed among bacteria community diversity of root domains of tree peony in different seasons. The com-munity diversity was higher in summer than in winter. The difference of rhizosphere bacteria diversity was the largest, the smallest in the rhizoplane. Plant-growth promotion functions of 122 bacterial strains isolated from the rhizosphere of tree peony plants were preliminarily screened. Results showed that there were 20 strains with siderophore-producing activity, 14 strains with phosphate -solubilizing activity, and 24 strains with IAA producing activity, accounting for 16.39%, 11.48%, and 19.67% of all the bacterial strains, respectively.