Determination of the antibiosis relationship between bean root fungi and rhizosphere bacteria

In this study, the antibiosis effects of rhizosphere bacteria obtained from bean plants and soil samples collected from the Doğanhisar, Sarayönü, Bozkır, and Çumra districts of Konya province were investigated against Fusarium oxysporum, Rhizoctonia solani, Macrophomina phaseolina, and Alternaria alternata causing diseases in beans. A total of 300 bacterial isolates were obtained and tested under laboratory conditions using the dual culture method. Among the tested bacterial isolates, 20 showed significant antagonistic effects. According to the results of the dual culture tests, the most effective bacterium against F. oxysporum was identified as Bacillus mojavensis with an inhibition rate of 53.37%, against R. solani as Bacillus atrophaeus with an inhibition rate of 55.34%, and against M. phaseolina as Bacillus subtilis with an inhibition rate of 54.49%. Among the fungal pathogens of bean roots, the highest effect was obtained against A. alternata with an inhibition rate of 64.23% by Bacillus atrophaeus. As a result, it can be concluded that the antibiosis activity against bean root fungi may vary depending on the bacterial species and even among different isolates of the same species. Keywords: Bean, fungus, antibiosis, rhizosphere bacteria