Integrated watermelon genetic map and QTL position. Chromosome 1 to 11 of watermelon are according to Ren et al. . The map distance is given on the left in centimorgans (cM) from the top of each chromosome.QTL are located in a skeleton bins of the integrated map chromosomes 1 to 11. QTL are designated according to Additional file 1: Table S5, QTL’s positions were defined by the support interval. Skeleton bins of each chromosome are indicated as black dashes. Brix (BRX), fructose(Fru), sucrose (Suc), glucose (Glu), fruit weight (FWT), fruit length (FL), fruit width (FWD), fruit shape index (FSI), rind thickness (RTH), 100 seed weight (100SWT), seed length(SL), seed width (SWD), seed oil percentage (SOP) and egusi (eg) seed loci are represented by different colours. The brix loci were identified in this research while the BRX loci were identified by previous research .