62 Background controlled QTL mapping in pure-line genetic populations derived from four-way crosses.Heredity

S Zhang^#, L Meng^#, J Wang^# and L Zhang*. Background controlled QTL mapping in pure-line genetic populations derived from four-way crosses.Heredity.119:256–264.

Pure lines derived from multiple parents are becoming more important because of the increased genetic diversity, the possibility
to conduct replicated phenotyping trials in multiple environments and potentially high mapping resolution of quantitative trait
loci (QTL). In this study, we proposed a new mapping method for QTL detection in pure-line populations derived from four-way
crosses, which is able to control the background genetic variation through a two-stage mapping strategy. First, orthogonal
variables were created for each marker and used in an inclusive linear model, so as to completely absorb the genetic variation in
the mapping population. Second, inclusive composite interval mapping approach was implemented for one-dimensional
scanning, during which the inclusive linear model was employed to control the background variation. Simulation studies using
different genetic models demonstrated that the new method is efficient when considering high detection power, low false
discovery rate and high accuracy in estimating quantitative trait loci locations and effects. For illustration, the proposed method
was applied in a reported wheat four-way recombinant inbred line population.

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