Floweringtimeisanimportanttraitdeterminingsoybeanecologicaladaptabilityandyield.Itisofgreatsignificancetounderstandthegeneticbasisandthemolecularmechanismoffloweringregulationinsoybean.Inthecurrentstudy,87soybeanvarietiesfrom3majorsoybeanproducingareas(NorthernSpring-sowingRegion,
Huang-Huai-HaiRiversValleyandSouthChina)ofChinaand31fromUSAwereplantedinspringandsummerrespectivelyinBeijing.Dataforfloweringtimeunder10sowingdateswereobtained.SNPanalysiswascarriedoutusingIlluminaBARCSoySNP6KiSelectBeadChip.Throughtheanalysisofpopulationstructure,Neighbor-joining
andPCA,soybeanvarietieswereclassifiedinto2sub-groups.Thegenome-wideassociationstudy(GWAS)betweenthefloweringtimeand5126SNPswereimplementedwithPCA+KmodelusingTASSELsoftware.Atotalof18significantlociassociatedwithsoybeanfloweringtimewereidentified.Amongtheloci,14weredetectedinmorethan2environments,indicatingthattheselociwerelessinfluencedbytheenvironmentalfactorsandcouldstablyexpressacrossdifferentenvironments;4weredetectedonlyinasingleenvironment,suggestingthattheyweresusceptibletophoto-thermalconditions.Newcandidategenesmightexistintheunreortedloci,whichwerelocated at3,4,5,9,10,14,16and17chromosomesunderlyingfloweringtime.31candidategeneswerepredicatedthroughannotation,inwhich2geneshavebeenprovedtobeinvolvedinfloweringregulationofsoybean,andGlyma03g33470,Glyma11g15650,Glyma05g01510andGlyma19g07162weresoybeanorthologsoftherelatedflowergenesinArabidopsis,indicatingthatthese4geneswereunderlyingfloweringtimeinsoybean.