Genetic map of chromosome 7A showing Rlnn1, Lr20/Sr15, Psy-A1 and molecular marker loci. From left to right: a map showing the relative locations of the Pratylenchus neglectus resistance locus Rlnn1, the leaf rust resistance locus Lr20 and seven molecular markers, as reported by Williams et al. ; a map showing the relative locations of the resistance locus Lr20/Sr15, the phytoene synthase gene Psy-A1 and 39 molecular markers mapped on the chromosome 7A using a population of Excalibur/Kukri doubled haploid lines; and a graph showing a LOD test-statistic scan from simple interval mapping of resistance against the root lesion nematode Pratylenchus neglectus in the Excalibur/Kukri population, with resistance evaluated based upon estimation of the quantity of P. neglectus DNA in the roots of inoculated wheat plants. The names of three loci common to both maps are underlined. The names of five newly developed EST-based markers are shown in red.