Screening and identification and antagonism research of two biocontrol bacillus strains

Abstract:

[Objective] This study aimed to screen biocontrol bacillus strains with broad-spectrum and highly efficient antagonistic activity against plant pathogen fungi, and further to study the antagonist function. [Methods] Present study used eight kinds of plant pathogenic fungi as target bacteria to screen superior bacillus strains from 9 candidate strains, the method of flat confrontation, antagonistic activity determination of fermentation filtrate were used. [Results] Two bacillus strains B06 and B07 were found with the characteristics of broad-spectrum and highly efficient antagonistic activity. B06 was more effective in inhibiting 8 pathogenic fungi than other strains, with R2/R1 ranging from 0.4 to 1.8, and the inhibition rate of sterile fermentation filtrate from 66.7% to 87.5%. B07 took second place in inhibiting 8 pathogenic fungi than other strains, with R2/R1 ranging from 0.23 to 1.21, and the inhibition rate of sterile fermentation filtrate from 55.56% to 81.25%. Bacillus strains B06 and B07 were both identified as Bacillus amyloliqueaciens with the methods of 16S rDNA sequence analysis. [Conclusion] The result indicates that bacillus strain had the ability to inhibit kinds of plant pathogen fungi. Screening of bacillus strains with broad-spectrum and highly efficient antagonistic activity has a great development and application value in agricultural biological control.