Isolation, identification and laboratory toxicity determination of Fusarium oxysporum from watermelon root rot

In this study,ten strains were taken at the colony edge for subculture and purification from watermelon root rot.The purified isolates were primarily identified based on morphological and colony characteristics.seven species belonged to Fusarium oxysporum,three species belonged to F.moniliforme and one species belonged to F.solani.Our pathogenicity test showed that F.oxysporum was major pathogen of root rot than F.moniliforme(28.4%) and F.solani 29.7%,which pathogenic rate up to 88.2%.In addition,the toxicity of 6 fungicides to F.oxysporum was tested.The result showed that carbendazim and marigold bactericidin diplayed obvious inhibitive effects.