简介：EighteenisolatesofRhizoctoniasolanicollectedfrominfectedriceplantsinfourdifferentlocationsofBangladeshwerestudiedbyusingmorphologicalcharactersandmolecularmarkers.AnastomosisstudywithareferenceisolateconfirmedthatalltheisolatesbelongedtoR.solani.Significantvariationwasobservedinsclerotialsize,shapeanddistribution.Un-weightedpairgroupmethodwitharithmeticmeandendrogramconstructedbasedontheGower’sgeneralsimilaritycoefficientshowedthattheseisolatesweregroupedintofourclustersatthe0.68similaritycoefficentaccordingtomorphologicalcharacters.ClusterIwasamajorclusterconsistingof13isolates,whileclustersⅡtoⅣconsistedof1or2isolates.Analysesbyvariablenumberoftandemrepeatandamplifiedfragmentlengthpolymorphismmarkersshowedthattheisolatesweregroupedintofiveandthreeclustersatasimilaritycoefficientof0.64and0.69,respectively.Althoughmostofthevariabilitywasfoundbetweenisolatesfromdifferentregionsasexpected,significantvariationwasobservedwithintheisolatescollectedfromsimilaragro-ecologicalregions.OurresultssuggestthepresenceofdifferentracesofR.solaniwithinthesamelocalgeographicregions.