Resistance Of Botrytis Cinerea To Three Fungicides In Baise Region In Guangxi And Analysis On Control Effect Of The Fungicides

The sensitivity of fungicide resistance of 112 sampling isolates of Botrytis cinerea from tomato grown in Baise region in Guangxi to three fungicides was determined.The results showed that the EC50 of 5 isolates with middle sensitive was 0.0172 ?/mL for fludioxonil,0.4344 ?g/mL for iprodione,and 0.1022 ?g/mL for tebuconazole.The EC50 of the five most sensitive isolates was 0.0074 ?g/mL for fludioxonil,0.1332 ?g/mL for iprodione,and 0.0252?g/mL for tebuconazole.Two mutants M2 and M3 resistant to iprodione were induced by ultraviolet light and fungicide.The EC50 of the two mutants to iprodione was 674.484 ?g/mL and 1023.574?g/mL,respectively,and was 597.63 times and 906.94 times that of wild isolate(EC50 was 1.1226 ?g/mL).The resistance of the two mutants was stable in preliminary tests.Mycelial growth rate of the mutants decreased,ability of sclerotia formation of the mutants increased,pathogenicity of the mutants to detached leaves of tomato decreased,cell membrane permeability of the mutants weakened,the mutants were more sensitive to osmotic pressure,a varying degrees of changes of enzymes activity of the mutants was detected,a obvious changes of transcriptome metabolism of the mutants was detected,by a compare with wild isolate.The technique of artificial inoculation for inducing disease of tomato gray mold was optimized.A stable and ideal effect for inducing the disease was obtained,by a inoculation with a mixture of high temperature sterilized tomato juice and conidia,on back side of detached leaves of tomato,under the condition of no wound.The control experiments of three fungicides,fludioxonil,iprodione,tebuconazole,were carried out by artificial inoculation to inducing the disease with detached leaves.By using the concentration in the field application as instructed by commercial product,the protective effects were all 100.00%for the three fungicides.Curative effect was 54.17%for fludioxonil,12.20%for iprodione,and 63.39%for tebuconazole.Systemic control effects was 40.00%for fludioxonil,52.59%for iprodione,and 60.74% for tebuconazole.