Study on Resistance of Fusarium graminearum to Carben dazim

54 isolates of Fusarium graminearum collected from Nanjing in 1976, 78 isolates from the same plot in 1983 and 104 isolates from Shanghai, Fujian, Anhui, Jiangsu and Hubei in 1998 were detected for the sensitivity to carbendazim (MBC) with EC50 0.2617～ 0.6544, 0.2517～ 0.7050, 0.2478～ 6.4574 μg·mL - 1 ,respectively. The result showed the mutants of MBC-resistant existed in the field of Hubei, Zhejiang, Shanghai, etc. The mutant with EC50 14. 1993 μg ·mL - 1 w as also obtained when its conidiospores were irradiated with UV -ray. There were no significant difference in mycelia grow th rate and sporulat ion between mutant JPR and its parentsiso late JPS. The conidial germ ination percentage of JPR w as only 57. 1% while that of JPS w as 100%. The 50% conidial germ ination of JPR lagged 12 hours behind JPS. JPR produced 3.90 μg·mL - 1 deoxynivaleno l (DON toxin) while JPS produced 9. 28 μg·mL - 1 .