Resistance induction of Fusarium graminearum to tebuconazole and bionomics of resistant-mutants

Eight tebuconazole-resistant mutants were obtained by ultraviolet-induction of Fusarium graminearum,and the average of resistance rate was more than 30 and the highest resistance rate was 186.03.The resistant rate of resistant mutants gradually decreased after 9 generations of subcultures in the absence of fungicides and the resistance obtained could be unstable.The colonies growth diameter,mycelial weight and the sensitivity to pH value and temperature of resistant mutants were significantly lower than their parent isolates.Tebuconazole-resistant isolates of F.graminearum showed moderate or high risk and no cross-resistance to difenoconazole,carbendazim,iprodione,chlorothalonil and thiram.