In vitro inhibition activity of antagonistic bacterium against Fusarium oxysporum f. sp. cubense

Six bacterial isolates(i.e.,B05,B23,B44,B105,B133 and B146)showed considerable antibiosis toward race 4 of Fusarium oxysporum f.sp.cubense,the Panama wilt pathogen of banana.Diameter of the inhibition zone ranged from 10 mm to 15 mm by pairing culture on PDA plate.The rate of pathogen mycelium growth inhibition of the bacterial isolates culture liquid ranged from 83.71% to 88.76% on PDA plate,as compared to 16.85% to 33.48% of the liquid after autoclave at 15 psi(121℃) for 20 min.The non-volatile and volatile active metabolites of the isolates showed inhibition rates on the pathogen's mycelium growth ranging from 74.72% to 87.36% and from 15.30% to37.64%,respectively.The culture filtrates of all isolates were found to be effective in reducing spores germination of F.oxysporum.Among them,B05 showed the most stable and greatest inhibition activity,while B44 most effective in inhibiting the spore germination.