Furtherimprovementofriceproductivityremainsachallenge.Breedingisperceivedasanimportantoptiontoincreasericeyield.However,thegeneticprogressofgrainyieldinmostricebreedingprogramswasslowinthelastdecades.Althoughgreatprogressinricegenomicsandmolecularbiologyhasbeenachieved,theeffectofsuchtechnologicalinnovationsonricebreedingisfarsmall.Markerassistedselection(MAS)forafewtargetquantitativetraitloci(QTLs)hassignificanteffectsinimprovingqualitativetraits,suchasdiseaseresistance.ThesuccessofMAShasthereforemotivatedbreederstoidentifyandusemajorQTLsforyieldandyieldcomponenttraits.Inthisreview,wesummarizedtherecentmethodsinQTLidentification,includingnovelstatisticalmethodsforlinkageandassociationmapping,specialpopulationtypes,andwhole-genomesequencing.Wereviewedthesuccessfulapplicationofmarker-assistedgeneintrogressionandgenepyramidingtoimprovegrainyieldanddiscussedthedesignofefficientMASschemestofurtherincreasethesuccessrateofbreedingprograms.Theuseofwell-characterizedmajorQTLsthroughintrogressionandgenepyramidingisproveneffectiveinimprovinggrainyield,particularlyyieldunderabioticstress.MajorQTLsthatarestableacrossgeneticbackgroundandgrowingenvironmentsareoftenfoundinlessadaptedgermplasms,suchaslandracesandwildrelatives.AdvancedbackcrossQTLanalysisandintrogressionlines,whichintegrateQTLdiscoveryandutilization,areimportantmethodsforexploitingmajorQTLscontainedinsuchgermplasms.NextgenerationsequencingsubstantiallyincreasesmappingresolutionandacceleratestheidentificationofcasualgenesunderlyingmajorQTLs.Practicalguidelinesderivedfromtheoreticalandempiricalstudiesaregiventoguidethedesignofefficientmarker-assistedgeneintrogressionandpyramidingschemes.
