Identification Of QTL And The Genetic Basis Dissection For Crude Fat Content In Rice

With peoples' life level and market economics developing, concern of rice qualityimprovement was increasingly received. Especially, in recent years, improvement of ricebetter taste has become major subjects for many breeding programs in Southern China,where more and more hybrid rice was planted. Crude fat acid (CFC) is not only one ofmajor nutritional substance of rice, but also it can influence eating and cooking quality ofrice. As it was showed by someone else, fat content of rice will be increased with theclass of rice quality improvement, and the more of crude fat content, the better of the riceelongation and the quality of rice when rice was cooking. So it is. necessary tocomprehensively clarify its genetic mechanism for rice quality improving program.In this study here, a DH population concluding 190 lines derived from anotherhybrid F₁ between Zhenshan97B(indica) and Wuyujing2(japonica), and two backcrosspopulations from the DH lines backcrossed to two parents respectively were used to scanQTLs and dissect gene effects for the crude fat content. The aim is to provide theories forimproving rice quality by molecular marker-based selection. The main results were asfollowed:In three populations, fourteen QTLs were resolved, distributing on chromosome 1, 3,5, 6, 7, 8 and 9. Six QTL were detected in DH lines, and these QTL explained 42.37% ofphenotypic variation collectively, and four QTL were detected in two backcrosspopulations BC(Zhenshan97) and BC(Wuyujing2) respectively. Four out of fourteen lociwere detected repeatedly in both populations, DH and backcross populations Such as, thelocus on chromosome 7 between RM346-RM70 was detected in both populations, DHlines and BC(Zhenshan97). And another locus located on 3rd chromosomes betweenRM132-RM175 was also scanned in two populations, DH lines and BC (Zhenshan97).Among of these loci, a major QTL qCFC5 was located on chromosome 5 betweenmarkers RM87-RM334, which was detected simultaneously among three populations.Then, 5 digenic epistac QTLs were detected in three populations. By QTLs analysis, weconcluded that main-effect QTLs play a major role in controlling crude fat content ofbrown rice with modifying by several min-effect QTLs and epistatic effects. It can be concluded from the analyses of descriptive statistics for fat content in threepopulations that crude fat content will increase when DH population backcrossing to ahigher value parent, and will decrease when backcrossing to a lower fat content parent.