Linkage maps of the regions in which the Rcr1 gene is located. Broken lines drawn regions defined by different molecular markers on B. rapa linkage group A03. A) Rough mapping of Rcr1 based on a small F1 population (300 plants) derived from ACDC × FN. The genetic distance is shown on the left. B) Fine mapping of Rcr1 based on 1,587 F1 plants. C) Physical locations in Mb (left) of the molecular markers and TIR-NBS-LRR genes in the region flanked by the markers sN8591 and sR6340I.