Figure 3.  PEK locus is fine-mapped to a ~50 kb interval including a cluster of TIR-NBS-LRR receptors.  a) Fine mapping with five makers on a BC1S1 population ( = 695) located the PEK  locus between 3.97 and 8.45 Mb. Marker names, genetic distance (cM) and physical distance 9 are given. b) Genotype and phenotype of 64 recombinants used for recombinant analysis. Recombinants with same genotype are represented by a single haplotype (“hap.”). Blue bars represent homozygous DG-S1 allele (S/S), light red heterozygous (R/S), dark red homozygous SF48-O1 genotype (R/R). Phenotype of each haplotype (HR presence/absence) is shown on the left side: “-” means susceptible (S, no HR), “+” means resistant (R, strong HR). Numbers under each dashed line indicate the recombinants between each marker and the phenotype. c) PEK  locus is fine-mapped to a ~50 kb interval (genome C2 v1.0) containing eleven genes and a cluster of four TIR-NBS-LRR (green). A full list of genes within the PEK locus is reported in Table 3.
We performed an additional recombinant screening on four BC1S2 populations that were generated from four R plants with heterozygous genotype (PEK- SF48/pek -DG1) at the locus (Supporting information: Fig. S6). All four BC1S2s showed the expected 3:1 phenotypic segregation ratio between R and S plants (Supporting information: Table S1). Informative recombinants between M12 and M15 were identified in all populations (7 in BC1S2-2, 12 in BC1S2-3, 2 in BC1S2-4, 8 in BC1S2-5) and genotyped with additional markers (M26, M27, M28, M30). In all populations, S plants had homozygouspek- DG1 allele at markers M26, M27 and M28. One R recombinant in population BC1S2-3 was homozygous pek- DG1/pek- DG1 at M28, thus confirming the right border of the locus.