简介：InvitrodetectionmethodforthesensitivityofMagnaporthegriseatotricyclazolewasstudied,andthepotentialresistanceriskofblastdiseasetotricyclazolewasassessed.BothEC50ofhyphalmelanization(EC50-H)andminimuminhibitiveconcentrationofmelanizationinappressorial(MIC-A)byinhibitortricyclazoleshowedpositivecorrelationtotheEC50oftricyclazoleagainstblastdiseasetestedinvivo,withrelativeco-efficiency(R2)of0.8995and0.8244,respectively.However,stabilityandreproducibilityofEC50-HwerebetterthanthoseofMIC-A,suggestingthatitcouldbeusedtodetectthesensitivityofM.griseatotricyclazoleinvitro.TricyclazolesensitivityoftheprogeniesderivedfromsinglesporesofthemostsensitiveisolateDY2andtheleastsensitiveisolateGY6detectedinsensitivitymonitoringin2000wasnotstable,withmeanEC50valuesof4.4968μg/mLand5.4010μg/mL,respectively,indicatingthatthedifferenceinEC50betweenDY2andGY6wasnotcausedprobablybyresistancevariation.EC50ofGY6didnotincreasesignificantlywhencontinuouslyselectedfortwentygenerationsundertheselectionpressureoftricyclazoleinvivo.However,thesensitivityofDY2wasdecreasedby10-foldafterselectedfortwentygenerations.TheresultssuggestedthattricyclazolewasstilllowresistanceriskforM.griseainChina.