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Plant growth-promoting rhizobacteria (PGPR) have been widely recognized as an important agent,especially as a biofertilizer,in agricultural systems.The objectives of this study were to select efective PGPR for Chinese kale (Brassica oleracea var.alboglabra) cultivation and to investigate the efect of their inoculation on indigenous microbial community structure.The Bacillus sp.SUT1 and Pseudomonas sp.SUT19 were selected for determining the efficiency in promoting Chinese kale growth in both pot and field experiments.In the field experiment,PGPR amended with compost gave the highest yields among all treatments.The Chinese kale growth promotion may be directly afected by PGPR inoculation.The changes of microbial community structure in the rhizosphere of Chinese kale following PGPR inoculation were examined by denaturing gradient gel electrophoresis (DGGE) and principal coordinate analysis.The DGGE fingerprints of 16S rDNA amplified from total community DNA in the rhizosphere confirmed that our isolates were established in the rhizosphere throughout this study.The microbial community structures were slightly diferent among all the treatments,and the major changes depended on stages of plant growth.DNA sequencing of excised DGGE bands showed that the dominant species in microbial community structure in the rhizosphere were not mainly interfered by PGPR,but strongly influenced by plant development.The microbial diversity as revealed by diversity indices was not diferent between the PGPR-inoculated and uninoculated treatments.In addition,the rhizosphere soil had more influence on eubacterial diversity,whereas it did not afect archaebacterial and fungal diversities.
Plant growth-promoting rhizobacteria (PGPR) have been widely recognized as an important agent, especially as a biofertilizer, in agricultural systems. These objectives of this study were to select efective PGPR for Chinese kale (Brassica oleracea var. Alboglabra) cultivation and to investigate the efect of their inoculation on indigenous microbial community structure. The Bacillus sp. SUT1 and Pseudomonas sp. SUT19 were selected for determining the efficiency in promoting Chinese kale growth in both pot and field experiments. In the field experiment, PGPR amended with compost gave the highest results among all treatments. The Chinese kale growth promotion be be directly a fected by PGPR inoculation. changes of microbial community structure in the rhizosphere of Chinese kale following PGPR inoculation were examined by denaturing gradient gel electrophoresis (DGGE) and principal coordinate analysis. DGGE fingerprints of 16S rDNA amplified from total community DNA in the rhizosphere confirmed th at our isolates were established in the rhizosphere throughout this study.The microbial community structures were slightly diferent among all the treatments, and the major changes depended on stages of plant growth. DNA sequencing of excised DGGE bands showed that the dominant species in microbial community structure in the rhizosphere were not mainly interfered by PGPR, but strongly influenced by plant development. microbial susceptibility as revealed by diversity indices was not diferent between the PGPR-inoculated and uninoculated treatments. In addition, the rhizosphere soil had more influence on eubacterial diversity, yet it did not afect archaebacterial and fungal diversities.