Antibacterial effect of flower essential oils and plant organ's extracts of purple coneflower on the bacterium Pectobacterium carotovora pv. Carotovora in laboratory condition

Recently، plant pathogen’s biocontrol is a priority considering hazards and environmental threats of chemical pesticides. Using plant materials as antimicrobes has typically attracted many attentions. The aim of current study was evaluation of plant materials obtained from purple coneflower against Pectobacterium caratovorum subsp. caratovorum the casual agent of potato soft rot. Aqueous، acetone، methanol، ethanol and HCl extracts of coneflower root، stem، leaf and flower were obtained byrotary set while flower essential oils were extracted using Clevenger apparatus. The antimicrobial activity of coneflower extracts and essential oil was evaluated in laboratory with disc diffusion and minimal inhibitory and bactericidal concentration methods. The bacterium was more sensitive to flower essential oil than extracts. Root extracts were more inhibitory compared with other organs’ extracts. Also، aqueous and acetone extracts had very limited antibacterial activities on studied bacterium. Leaf extract possessed more growth inhibitor characteristic rather than bactericide traits. Regarding the results، plant materials obtained from coneflower could be a potent candidate against potato soft rot bacterium and might be considered as a promising biocontrol agent in the future.