Identification of Pathogen Causing Tomato Fusarium Wilt and Screening of Its Antagonistic Microorganisms

The pathogen was isolated from the root of the Fusarium wilt infected tomato by tissue isolating method,and identified as Fusarium oxysporum according to the morphology,pathogenicity and sequence analysis of the internal transcribed space region of the ribosomal DNA(ITS).The microbial quantity of the Fusarium wilt infected,healthy tomato root rizosphere substrates,and non-rizosphere field soils and the mountain soils were studied.From the soils,77 isolates were got and had certain inhibiting action on tomato Fusarium wilt by dual culture and 24 isolates with higher bio-control effect were obtained through further screening.The results also showed that the mountain soil had less biomass,but more antagonistic strains,and the fungus A6,A29,A9,A31,A44 and A28,which had the higher antagonistic effect,were isolated.