Fig. 2. Linkage groups on the long arms of maize chromosomes two (left) and four (right). Molecular marker loci are listed to the right of the linkage group, and the intervals in centimorgans are shown to the left. The total length of the linkage group on 2L is 121 cM (includes markers from bins 2.08 and 2.09) and 73 cM on 4L (includes markers in bins 4.08 to 4.11). Black arrows indicate significant marker intervals, ! = marker used as a co-factor, # = marker flanks a significant interval. All markers in bold were added for genetic map construction after initial QTL detection identified these chromosomes as associated with resistance.