To compare genetic maps and view marker correspondences between linkage groups in the MapViewer select the "Show Comparison Map" checkbox in the control panel. Two linkage groups will be drawn, the reference linkage group on the left, and the comparison linkage group on the right.
Scroll the zoomed section on each linkage group to view various areas. Zooming in on each side exposes further details for each linkage group along with correspondences enabling to focus on specific relationships of markers in common between the two linkage groups.