Abstract:
Rhizospheric microorganism can improve the root development and plant growth.To explore the diversity of the D. nobile rhizospheric bacteria,based on dilution plating technique and 16S rDNA sequence analysis method,the bacteria were isolated and identified from the rhizospheric soil of D. nobile cultivated in Guiyang,Jinsha and Chishui,Guizhou Province.And then the antimicrobial isolates were screened by plate punch method or confrontation culture method.The results showed that a total of 1010 bacterial strains were isolated,and 67 operational taxonomic units (OTUs) were identified,which affiliated to 32 genera,6 phyla including Firmicutes,α-Proteobacteria,β-Proteobacteria,γ-Proteobacteria,Bacteroidetes and Actinobacteria.Among them,Firmicutes (54.5%) and Bacillus (44.5%) were dominated.The community composition of rhizospheric bacteria was varied by cultivated regions of D. nobile,and Shannon-Wiener index was from 2.80 to 2.94.Additionally,there are 23 antimicrobial isolates screened,of which JCSHGTTB03-24 and CYSHGTR2A05-20 showed antimicrobial activity against various plant pathogens.The diversity of cultivable rhizospheric bacteria is abundant and has potential bioactivity.This study provides valuable bacteria resources for D. nobile cultivation and agricultural biocontrol in the future.