简介：Ricefieldsareecosystemswithmanytypesofplants,microbes,invertebrates,birdsandanimals.Thericefarmingprotectsthebiodiversityoftheregionandmaintainstheecosystemforthebenefitofenvironment.Somericevarietiesreleasebiocidalallelochemicalswhichmightaffectmajorweeds,microbialandpathogenicdiversityaroundriceplants,evensoilcharacteristics.Alargenumberofcompoundssuchasphenolicacids,fattyacids,indolesandterpeneshavebeenidentifiedinricerootexudatesanddecomposingriceresidues,asputativeallelochemicalswhichcaninteractwithsurroundingenvironment.Sincetheseallelopathicinteractionsmaybepositive,theycanbeusedaseffectivecontributorforsustainableandeco-friendlyagro-productionsystem.Geneticmodificationofcropplantstoimprovetheirallelopathicpropertiesandenhancementofdesirabletraitshasbeensuggested.Developmentofcropswithenhancedallelopathictraitsbygeneticmodificationshouldbedonecautiously,keepinginviewoftheecologicalriskassessment(non-toxicandsafeforhumansandecosystem,cropproductivity,ratioofbenefitandcost,etc.).