Fine mapping of a major flowering time QTL on soybean chromosome 6 combining linkage and association analysis
- 873 Downloads
Flowering time is a key trait in the plant life cycle and an important selection criterion for soybean. Here, we combine the advantages of genome-wide association and linkage mapping to identify and fine map quantitative trait loci (QTLs) associated with flowering time. Linkage mapping was performed using 152 recombinant inbred lines and a major QTL, qFT6, affecting flowering time was found on chromosome 6. To refine the qFT6, the 192 natural accessions were genotyped using eight new simple sequence repeats and 10 single nucleotide polymorphisms markers covering the qFT6 region Haplotype analysis showed that the haplotype between markers BARC-014947-01929 and Satt365 could explain more phenotypic variation (26.5 %) than any other combination of markers. These results suggested that the target flowering time gene was located in ~300 kb between BARC-014947-01929 and Satt365, including three predicted genes. High-resolution map in qFT6 region will be useful not only for marker-assisted selection of flowering time but also for further positional cloning of the target gene. These results indicate that combining association and linkage mapping provides an efficient approach for fine mapping of soybean genes.
KeywordsFine mapping Flowering time Association mapping Linkage mapping Soybean
We thank Mr. Wang Wen Liang at Henan Agricultural University for assistance in investigating flowering time and performing the field experiments. Dr Zhiwu Zhang from Cornell University is thanked for his critical reading of this manuscript. This work was supported by National Basic Research Program of China (973 Program) (2010CB125906, 2009CB118400); National Natural Science Foundation of China (31000718, 31171573, 31201230), and Jiangsu Provincial Programs (BE2012328, BK2012768).
- Churchill GA, Doerge RW (1994) Empirical threshold values for quantitative trait mapping. Genetics 138:963–971Google Scholar
- Cohen-Zinder M, Seroussi E, Larkin DM, Loor JJ, Everts-van der Wind A, Lee JH, Drackley JK, Band MR, Hernandez A, Shani M (2005) Identification of a missense mutation in the bovine ABCG2 gene with a major effect on the QTL on chromosome 6 affecting milk yield and composition in Holstein cattle. Genome Res 15:936–944PubMedCrossRefGoogle Scholar
- Mansur L, Lark K, Kross H, Oliveira A (1993) Interval mapping of quantitative trait loci for reproductive, morphological, and seed traits of soybean [Glycine max (L.) Merr.]. Theor Appl Genet 86:907–913Google Scholar
- Wang Y (2001) Establishment and adjustment of RIL population and its application to map construction, mapping genes resistant to SMV and QTL analysis of agronomic and quality traits in soybeans. Nanjing Agricultural University, Doctor DissertationGoogle Scholar
- Wang S, Basten C, Zeng Z (2005) Windows QTL cartographer version 2.5. Statistical genetics. North Carolina State University, RaleighGoogle Scholar