▪ Abstract Quantitative trait locus (QTL) mapping is a highly effective approach for studying
genetically complex forms of plant disease resistance. With QTL mapping, the roles of
specific resistance loci can be described, race-specificity of partial resistance genes can be
assessed, and interactions between resistance genes, plant development, and the
environment can be analyzed. Outstanding examples include: quantitative resistance to the
rice blast fungus, late blight of potato, gray leaf spot of maize, bacterial wilt of tomato, and the …