Isolation Screening Identification And Preliminary Study Mechanism Of Antagonistic Bacterium Cylindrocarpon Destructans

This paper firstly screen with high antagonism against ginseng rust rot bio-control bacteria with Yanbian area of Jilin poplar branch and soil as experiment material; secondly, identify biocontrol bacteria strain; finally, preliminary study the mechanism of biocontrol bacteria on ginseng rust rot. The main results are as follows:A total of88bacterial strains were separate out from Yanbian area of Jilin province poplar branches and soil. Using confront culture method, it obtained from the5strains (Y-S-Y12strain, YBUN13strain, YBUN18strain, YBUN20strain and YBUN21strain) with high antagonism against ginseng rust rot pathogen strains.Through indoor and field control experiment of bacteriostatic test, strain Y-S-Y12inhibitory effect on ginseng rust rot. Antibacterial activities of strain Y-S-Y12was95.01%; antibiotic Y-S-Y12fermentation of concentrated liquid rate is69.41%; Y-S-Y12strain field efficiency highest, reached75.79%, but also promote the growth of ginseng. Through the study of the morphological characteristics, physiological, biochemical and16S rDNA sequence analysis of the Y-S-Y12strain, Y-S-Y12strain was Bacillus amyloliquefaciens.To concentrate Y-S-Y12strains and fermentation of the antimicrobial spectrum and under different conditions of inhibition were determined. The experimental results show that:in the experiment, bacteriostasis concentrate Y-S-Y12strains and fermentation are good for6pathogens the inhibitory effect of disease. Ginseng rust rot bacteria strain Y-S-Y12decay on poplar is the strongest, the inhibition rates were respectively100%and96%.At about pH6.18or20℃, Y-S-Y12strains and fermentation of concentrated liquid strong antibacterial activity. Antagonistic activity on temperature, pH and ultraviolet radiation has certain stability of fermentation broth of strain Y-S-Y12.It does not sensitive to proteinase K, trypsin and pepsin yet.