ABSTRACT
Methods for QTL mapping based on phenotypic data from a single environment or on mean values across multiple environments are well developed (Lander and Botstein 1989; Haley and Knott 1992; Zeng 1993,1994; Tinker and Mather 1995). When phenotypic data from mul tiple environments are available, some QTL mapping tools can identify QTL for genotype main effect and QTL for GE interaction (e.g., Tinker and Mather 1995; Wang et al. 1999). However, these methods do not re veal the QEP, an understanding of which is essential to effective marker-based selection.
