Mapping And Validation Of QTLs For Seed Color In Brassica Rapa

The female parent ’RcBr’ is an inbred lines with yellow color, European oil type. The male parent ’08A061’ is an inbred lines with brown seed color, Brassica rapa. Based on F2, F6 population derived from RcBr and 08A061, the QTL mapping of seed color was completed. At the same time, European Brassica campestris (RcBr) as backcross, until BC4F4 generations. A QTL-NIL of controlling seed color was developed. The main experimental results were described as follow:1. The QTL mapping results in F2 population:Based on LOD>9,4 of QTLs were detected on A09 linkage groups by Using Windows QTL Cartographer 2.0 and composite interval mapping method. Named as qSC-9-8, qSC-9-10, qSC-9-13, qSC-9-15, respectively, which explained phenotypic variation were 10.35%,13.48%,13.64%,12.46%, respectively.2. The QTL mapping results in F6 population:Using visually, CR-400 colorimeter two measures to gain seed coat color phenotype datas. By using the same detection method in F2 population, we detected 9 QTLs, Which distributed over A02, A03, A06 and A09 linkage groups. A02:1 QTL, A03:2 QTLs loci, A06:2 QTLs loci, A09:4 QTLs loci. The same QTLs were detected on the A09 linkage groups in F2 population.3. In order to verify the accuracy of the detected QTLs loci, BC4F4 backcross populations were derived.The ’08A061’ was as donor parent, and the ’RcBr’ was as receptor or the recurrent parent. A QTL-NIL of controlling seed color was constructed using marker-assisted selection of each generation of target QTL for foreground selection, and ’RcBr’ as genetic background for background selection, then with the method of genotype and phenotype. Finally, a near isogenic lines were constructed with only different in A03 linkage group.