Figure 1
From: Entering the second century of maize quantitative genetics
Nested association mapping (NAM) design. (a) The maize NAM population was created by crossing 25 diverse founder lines by the reference line B73. Single-seed descent and self-pollination for five generations were then used to generate 200 recombinant inbred lines (RILs) for each subfamily. Figure based on Yu et al. (2008). (b, c) Identifying significant associations in NAM proceeds through two routes. Joint linkage mapping (b) across the subfamilies can identify quantitative trait loci (QTL) for specific traits at moderate resolution by taking advantage of the shared B73 line in all the subfamilies (Li et al., 2011). Genome-wide association (c) instead uses the information of which chromosomal segments were inherited from which parent (top) to project dense genotyping from the founder lines onto the progeny for improved resolution (bottom). Colored bars show which parent the chromosomal segment originated from. Single-nucleotide polymorphisms (SNPs) in panel c are shown as either matching the allele present in B73 (white) or as the alternative allele (black).
