Genome wide distribution of crossovers in progeny strain 7C126 and SC05. Genome wide distribution of COs in (A) 7C126 and (B) SC05. Chromosomes 1-14 are lined up from top to bottom. Each line within a chromosome represents a single SNP marker. HB3 alleles are shown in green bars and Dd2 alleles are shown in red. 23 and 20 COs and putative gene conversion events were detected for 7C126 and SC05 respectively in the current MS marker based linkage map . In contrast, the 454 SNP marker map detected 27 and 24 COs for 7C126 and SC05 respectively. The 454 SNP marker map was successful in the discovery of previously unknown CO events (highlighted with black bars). Refined views of the previously unknown COs are depicted in Additional file 3.