Mapping of two QTLs for resistance to Hessian fly. Response to Hessian fly for each of 154 RILs was scored in the Jagger × 2174-derived RIL population using the method previously described . QTL analysis was performed with composite interval mapping (CIM) using WinQTLCart 2.5. The positions of marker loci are shown on the x-axis in centiMorgan (cM) distances. The horizontal dotted line indicates the logarithm of the odds (LOD) significance threshold of 2.5. The vertical dash line indicates the gene markers associated with the QTLs.