Estimating the locations and the sizes of the effects of quantitative trait loci using flanking markers
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The use of information from flanking markers to estimate the position and size of the effect of a quantitative trait locus (QTL) lying between two markers is shown to be affected by QTLs lying in neighbouring regions of the chromosome. In some situations the effects of two QTLs lying outside the flanked region are reinforced in such a way that a ‘ghost’ QTL may be mistakenly identified as a real QTL. These problems are discussed in the framework of a backcross using a regression model as the analytical tool to present the theoretical results. Regression models that use information obtained from three or more nearby markers are shown to be useful in separating the effects of QTLs in neighbouring regions. A simulated data set exemplifies the problem and is analysed by the interval mapping method as well as by the regression model.
Key wordsQuantitative trait loci Interval mapping RFLPS mapping
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- Haley CS, Knott SA (1992) A simple regression method for mapping quantitative trait loci in line crosses using flanking markers. Heredity, 69:315–324Google Scholar
- Hyne G, Snape JW (1991) Mapping quantitative trait loci for yield in wheat. In: Biometrics in plant breeding. Proc 8th Meet Eucarpia Section, Biometrics Plant Breed. Research Institute of Agroecology and Soil Management, Brno, Czechoslovakia, pp 47–56Google Scholar
- Jensen J (1989) Estimation of recombination parameters between a quantitative trait locus (QTL) and two marker gene loci. Theor Appl Genet 78:613–618Google Scholar
- Knapp SJ (1991) Using molecular markers to map multiple quantitative trait loci: models for backcross, recombinant inbreed and doubled haploid progeny. Theor Appl Genet 81:333–338Google Scholar
- Knapp SJ, Bridges WC, Birkes D (1990) Mapping quantitative trait loci using molecular marker linkage maps. Theor Appl Genet 79:583–592Google Scholar
- Luo ZW, Kearsey MJ (1989) Maximum likelihood estimation of linkage between a marker gene and a quantitative locus. Heredity 63:401–408Google Scholar
- Luo ZW, Kearsey MJ (1991) Maximum likelihood estimation of linkage between a marker gene and a quantitative trait locus. II Application to backcross and doubled haploid populations. Heredity 66:117–124Google Scholar
- Paterson AH, Lander E, Hewitt JD, Peterson S, Lincln SE, Tanksley SD (1988) Resolution of quantitative traits into Mendelian factors by using a complete linkage map of restriction fragment length polymorphisms. Nature 355:721–726Google Scholar
- Simpson SP (1989) Detection of linkage between quantitative trait loci and restriction fragment length polymorphisms using inbred lines. Theor Appl Genet 77:815–819Google Scholar
- Weller JI (1986) Maximurn likelihood techniques for the mapping and analysis of quantitative trait loci with the aid of genetic markers. Biometrics 42:627–640Google Scholar