Development Of Chromosome Segment Substitution Lines With Huazhan As Recipient And QTL Mapping For Several Agronomic Traits In Rice(Oryza Sativa L.)

Rice is one of the most important crops in the world and feeds more than one half of the world’s poplutation.Most of rice agronomic traits are quantitative traits.So,identification of these QTL is useful for rice breeding.Chromosome segment substitution lines(CSSLs)are considered to be the ideal material for QTL analysis,because each substitution line contains only one or a few fragments which are from the donor parent.In this study,a population consisting of 109 CSSLs was developed,derived from the crossing and back-crossing of two rice cultivars:Huazhan,as the recipient and 8001,as the donor.39 QTL for several agronomic traits were mapped.The main results are as follows:1.Development of 109 CSSLsA population consisting of 109 CSSLs was developed,derived from the crossing and back-crossing of two rice cultivars:Huazhan,as the recipient and 8001,as the donor using 224 polymorphic markers assisted selection(MAS).The 109 CSSLs carried 227 substituted chromosome segments.The length of substituted chromosome segments in the 109 CSSLs ranged from 0.05 Mb to 16.45 Mb,with an average of 2.05 Mb.The total length of substituted segments was 466.15 Mb,which was 1.25 times the total length of the rice genome.The average rate of coverage of substituted segments per chromosome was 74.86%.2.Mapping QTL for main agronomic traits of riceIn this study,a total of 39 QTL for 13 agronomic traits were mapped by using IciMapping.8,4,3,1,4,4,2,2,2,3,4,1 and 1 QTL were mapped for heading date(HD),flag leaf length(FLL),flag leaf width(FLW),tilling numbers(TN),panicles per plant(PPP),flag leaf area(FLA),panicle length(PL),diameter of the first internode from the top(DFI),diameter of the second internode from the top(DSI),diameter of the third internode from the top(DTI),grain length(GL),grain width(GW)and 1000-grain weight(TGW),respectively.