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.%应用组织分离法从发病番茄根部分离番茄枯萎病病原菌并进行致病性测定,根据菌体形态特征、ITS序列同源性分析将病原菌鉴定为镰刀菌属尖孢镰刀菌(Fusarium oxysporum).探讨了发病及健康番茄根际栽培基质、大田土及山地贫瘠土壤的微生物数量,采用平板对峙培养法初筛得到77个对番茄枯萎病病原菌有拮抗作用的分离物,进一步复筛得到24个拮抗性能较为稳定的分离物,其中来自山地土的真菌A6、A29、A9、A31、A44、A28拮抗作用较强.山地贫瘠土壤尽管微生物总量较少,但是分离获得的拮抗菌数量最多.
展开▼
