AN EXTENSION OF THE MARKER REGRESSION METHOD TO INTERACTIVE QTL

A regression mapping approach to localize simultaneously two unlinked interactive QTL is proposed. It extends the simple 'marker regression' method of Kearsey and Hyne (1994) to the case of two linkage groups, each with a single QTL having no additive (main) effect, and acting on ly through epistasis (interaction between a pair of QTL). It allows th e localization of the two QTL on the two linkage groups involved by a least square method, which is theoretically more precise than the clas sical study of interactions between pairs of markers. An application o f the method to interactive QTL controlling plant height in bread whea t is presented. Further possible developments are briefly discussed.