A MULTI-MARKER MODEL FOR DETECTING CHROMOSOMAL SEGMENTS DISPLAYING QTL ACTIVITY

A statistical method is presented for detecting quantitative trait loc i (QTLs), based on the linear model. Unlike methods able to detect a f ew well separated QTLs and to estimate their effects and positions, th is method considers the genome as a whole and enables the detection of chromosomal segments involved in the differences between two homozygo us lines, and their backcross, doubled haploid, or F2 progenies, for a quantitative trait. Genetic markers must be codominant, but missing m arkers are accepted, provided they are missing independently from the experiment. Asymptotic properties, which are of practical use, are dev eloped. This method does not rely on strong genetic hypotheses, and th us does not permit any precise genetic analysis of the trait under stu dy, but it does assess which regions of the genome are involved, whate ver the complexity of the genetic determinism (number, effects and int eractions among QTLs). Simultaneous use of several methods, including this one, should lead to better efficiency in QTL detection.