SSC2 haplotypes of the five progeny-tested sires. The pairs of haplotypes (0-75 cM) inherited by the five progeny tested sires from their two parents (062084 and 062408).Yellow refer to the IBD Meishan haplotype (associated with the backfat increasing QTL allele), all other colors refer to different Large White haplotypes (associated with the backfat decreasing QTL allele). In the white areas, the origin could not be defined. The progeny testing results obtained for each sire is indicated by a genotype at the SSC2 QTL (q/q for no segregating families, Q/q for segregating families). The dashed lines represent the position of the studied QTL based on the progeny-testing results of these sires.