简介：RicecropgrowthandyieldinthenorthIranareaffectedbycropdurationandphenology.ThepurposeofthisstudywastocalibrateandvalidatetheORYZA2000modelunderpotentialproductionbasedonexperimentaldataforsimulatingandquantifyingthephenologicaldevelopment,cropdurationandyieldpredictionofricecropinfluencedbydifferentseedlingages.InordertocalibrateandvalidatethecropparametersofORYZA2000model,atwo-yearfieldexperimentwasconductedunderpotentialgrowthconditio...

简介：Toprovidegeneticinformationandmaterialsforbreedinghybridjaponicaricewithwideadaptabilityandstrongcompetitiveadvantageofyield,eliteallelesandtheircarriervarietiesofgrowthduration(GD)andproductivepaniclenumberperplant(PN)weredetected.Anaturalpopulationcomposedof94japonicavarietieswasphenotypedfortheGD,PNandplantheight(PH)intwoenvironments.TheconditionalphenotypicdataweretransferredbythelinearmodelmethodinsoftwareQGAStation1.0,andassociationmappingbasedontheunconditionalandconditionalphenotypevaluesofGDandPNwasanalyzedbyusinggenerallinearmodelinsoftwareTASSEL.Atotalof34simplesequencerepeat(SSR)markerlociassociatedwithGDandPNweredetectedinthetwoenvironments.Amongthem,15wereassociatedwithGD,and19wereassociatedwithPN.FoureliteallelesofRM8095-120bp,RM7102-176bp,RM72-170bpandRM72-178bpwereassociatedwithGD,andtheircarriervarietieswereHongmangshajing,Nipponbare,HongmangshajingandNannongjing62401,respectively.TheseeliteallelesfromthecarriervarietiescanshortenGDby2.039.93dwhentheywereintroducedintoimprovedmaterials.RM72-182bpassociatedwithPNwasaneliteallele,anditscarriervarietywasXiaoqingzhong.ItcanincreasePNbythreewhenintroducedintoimprovedmaterials.Moreover,theseeliteallelescanbeusedtoimprovetargettraitswithoutinfluencinganothertwotraits.

简介：Nitrogen(N)useefficiencyisusuallylessthan50%,anditremainsamajorprobleminricecultivation.Controlledreleasefertilizer(CRF)technologyisoneofthewell-knowneffortstoovercomethisproblem.TheefficiencyofCRF,however,isverymuchdependentonthetimingofnutrientrelease.ThisstudywasconductedtodeterminetheprecisetimeofNuptakebyriceasaguidelinetodevelopefficientCRF.FertilizerNuptakebyriceatdifferentgrowthstageswasinvestigatedbyusing15Nisotopictechnique.Ricewasplantedinpots,with15NureaasNsourceattherateof120kg/hm2.Potassiumandphosphoruswereappliedatthesamerateof50kg/hm2.Standardagronomicpracticeswereemployedthroughoutthegrowingperiods.Riceplantswereharvestedeverytwoweeksuntilmaturationatthe14thweekandanalyzedfortotalNand15Ncontent.Nitrogenderivedfromfertilizerwascalculated.TotalNuptakeinplantsconsistentlyincreaseduntilthe11thweek.Afterthat,itstartedtoplateauandfinallydeclined.Moreover,Nutilizationbyriceplantspeakedat50%,whichoccurredduringthe11thweekaftertransplanting.Nderivedfromfertilizerinriceplantswereintherangeof18.7%to40.0%inallplanttissues.TheremainingNwasderivedfromsoil.Basedonthisstudy,NreleasefromCRFshouldcompletebythe11thweekafterplantingtoensurethemaximumfertilizerNuptakebyriceplants.EfficientCRFshouldcontributetohigherNderivedfromfertilizerwhichalsoresultedinahighertotalNuptakebyriceplants,increasingthepotentialofricetoproducehigheryieldwhileatthesametimeofreducingloss.