简介：Severalbacterialstrainswereisolatedfromdifferentrhizospheres.Amongthese,strainPDY7exhibitedstrongantibacterialactivityagainstthericebacterialblight(BB)pathogenXanthomonasoryzaepv.oryzae(Xoo)bythelaboratorydualplateassays.TheantibacterialpropertyofthestrainPDY7wasfurtherinvestigatedfortheproductionof2,4-diacetylphloroglucinol(DAPG),whichamplifiedacharacteristicof629-bpDNAfragmentbyPCR-basedscreeningmethodusingphlDprimers.TheapplicationofphlDpositivestrainswascarefullyevaluatedfordiseasecontrolandgrowthpromotionofriceplantsunderfieldconditions.TheselectedstrainPDY7suppressedthericeBBby58.83%and51.88%underglasshouseandfieldconditions,respectively.Inaddition,thestrainPDY7showedsignificanttwo-foldincreaseinrootlength(18.08cm),shootlength(29.81cm),andgrainyield(96.07g).StrainPDY7promotedthegrowthofriceplantsbyproductionofindole-3-aceticacid(IAA),whichwasdeterminedbyhighperformanceliquidchromatography(HPLC)analysis.OurfindingssuggestthatPDY7belongstotheP.fluorescensgroupandcanserveaspotentialbiocontrolofBBaswellasbiofertilizeragentforgrowthpromotionofrice.