Qtls Identification Of Stigma Traits Based On The Single Segment Substitution Lines Of Wild Rice

Rice(Oryza sativa)is a self-pollinating crop with low stigma exsertion,which limits theseed production in hybrid rice.As the ancestor of cultivated rice,wild rice has obvious stigma exsertion characteristics,which is closely related to its large stigma.Therefore,the QTLs identification and mapping of large stigma and high exsertion rate from wild rice will provide important guidance for breeding improvement of stigma exsertion rate of male sterile lines in hybrid rice.In this study,76 single segment substitution lines of O.barthii and 52 single segment substitution lines of O.meridionalis were used to identify QTLs related to stigma traits from 2016 to 2017,including QTLs of six traits(stigma exsertion rate,stigma brush-shaped part length,stigma non-brush-shaped part length,stigma length,stigma width,style length),and the correlation between these stigma traits was analyzed.The main results were as follows.(1)A total of 65 QTLs were identified in SSSLs of O.barthii.A total of 76 SSSLs were used to identify stigma traits from 2016 to 2017.A total of 11 QTLs with stigma exsertion rate,15 QTLs with stigma brush-shaped part length,8 QTLs with stigma non-brush-shaped part length,12 QTLs with stigma length,15 QTLs with stigma width,4 QTLs with style length were identified.The QTLs were distributed on 12 chromosomes.Among them,the most additive effect was qPESb1-2(114.52%).(2)A total of 29 QTLs were identified in SSSLs of O.meridionalis.A total of 52 SSSLs were used to identify stigma traits from 2016 to 2017.A total of 5 QTLs with stigma exsertion rate,8 QTLs with stigma brush-shaped part length,2 QTLs with stigma non-brush-shaped part length,9 QTLs with stigma length,5 QTLs with stigma width were identified.The identified QTLs were distributed on 3,5,8,10,11,12 chromosomes.Among them,the most additive effect was qSWm3-2(21.58%).(3)Major QTL.The main effect QTL of high stigma exsertion rate is qPESb1-2,and the phenotypic contribution rate is 114.52%;The main effect QTL of stigma brush-shaped part length is qSBPb4-1,the phenotypic contribution rate is 30.74%;The main effect QTL of stigma non-brush-shaped part length is qSNBPb10-1,and its phenotypic contribution rate is 33.29%;The main effect QTL of stigma length is qSLb4-1,the phenotypic contribution rate is 24.36%;The main effect QTL of stigma width is qSWb6-1,and the phenotypic contribution rate is 31.47%;The main effect QTL of style length is qSTYLb1-2,and the phenotypic contribution rate is 19.28%.(4)Correlation of stigma traits.According to the investigation of stigma traits in many seasons,it was found that stigma brush-shaped part length,stigma non-brush-shaped part length,stigma length and stigma width is positively correlated each other,the length of style is negatively correlated with other traits of stigma,and the stigma exsertion rate was positively correlated with stigma non-brush-shaped part length and stigma width.The correlation of stigma length and stigma brush-shaped part length with stigma exsertion rate is not clear.