Induction and Characteristics of Fungicide ZJ0712-resistantBlumeria graminis Mutants

Three fungicide ZJ0712-resistant B.graminis f.sp.tritici (Bgt) mutants Bgt01R,Bgt1-1R and Bgt2-1R were obtained from the sensitive isolates Bgt01,Bgt1-1 and Bgt2-1,respectively by the method of adaptation fungicide for ten generations.The resistance factors of all three mutants to ZJ0712 were greater than 80,and the resistance were stable through asexual reproduction.Inoculation tests showed that the virulence of the mutants was not significantly different from that of their parents.Comparisons of the nucleotide sequence of the partial cytochrome b (cyt b) gene from sensitive isolates and resistant mutants revealed that all three resistant mutants had a single point mutation of GGT (in sensitive isolates) to GCT (in resistant mutants),which caused a change of glycine (Gly) to an alanine (Ala) at codon position 143 (G143A) of the cyt b.The results indicated that the Bgt has a high risk of developing resistance to ZJ0712.In order to delay the development of ZJ0712 resistance in Bgt populations,effective anti-resistance strategies are needed when the fungicide is applied widely in fields.