吉林省水稻恶苗病菌对咯菌腈的敏感性及抗药性风险评估OA北大核心CSTPCD

The study aims to understand the sensitiveness of Fusarium fujikuroi to fludioxonil and as-sess the risk of resistance.From 2016 to 2018,508 strains of F.fujikuroi were isolated from 16 re-gions of Jilin province,and sensitiveness of 136 strains of F.fujikuroi to fludioxonil was determined by mycelial growth rate method.Resistant mutants of rice F.fujikuroi to fludioxonil were obtained by drug domestication.The results showed that EC50 values of 136 selected strains to fludioxonil ranged from 2.810 x 10-9 to 0.740 9 mg/L,which were extremely sensitive to fludioxonil.No resistant popu-lation was found,and the mean EC50 value was(0.024 9±0.093 6)mg/L,indicating that rice F.fujiku-roi in Jilin province did not develop resistance to fludioxonil.Compared with their parent strains,re-sistance levels of the two resistant mutants(LH10-2-11 and DH34-5-11)were 3 596.48 and 9 539.73 fold,respectively,showing high resistance.Through biological testing,adaptability of resistant mu-tants was proved to be extremely high,making them easy to become dominant fungi in the field.The results of cross resistance test showed that there was positive cross resistance between fludioxonil and thiram,thiophanate-methyl,metalaxyl-M and hymexazd,but no cross resistance with prochloraz and tebuconazole.The results suggested that the resistant mutants of F.fujikuroi from rice can be de-veloped under the selection of fludioxonil,which poses a risk of resistance to fludioxonil.The results lay foundation for the control of rice bakanae caused by F.fujikuroi and management of fungicide re-sistance of F.fujikuroi to fludioxonil.