Abstract:

This study was carried out to determine the antagonistic effects of 38 bacterial isolates isolated from the rhizospheric soil region of different plants against Sclerotinia minor Jagger, which is one of the causative agents of white rot in sunflower. Approximately 37% of the bacteria tested in vitro suppressed mycelial growth of the pathogen at moderate or high levels. Bacteria that inhibit pathogens at a high level (80-100%) in vitro (Pseudomonas chlororaphis IDV5, Bacillus amyloliquefaciens IEB1, Bacillus cereus IPT3, Stenotrophomonas sp. IGL1, 2 unidentified bacterial isolates (IFG1 and IFG2)) were potted under climatic chamber conditions tested by work. According to our research results, all bacteria except Pseudomonas chlororaphis were 100% effective in pot experiments. In addition, although it is ineffective against S. minor in vitro, Pseudomonas koreensis (IFG4), which we have found to be successful in vivo conditions in different studies we have done before, was included in the trial and was found effective in this study as well. This result shows that some inhibitory properties of some rhizospheric bacteria, which play a role in suppressing the pathogen, appear when they come together with the plant. In conclusion, our study reveals that biological control is one of the alternatives to control soil pathogens in sunflower and can be used as a bioagent after investigating other properties of these antagonistic bacteria.