Fig. 1

Breeding funnel of the MAGIC maize population. RIL were produced according to a funnel design with pooling to establish 35 subfamilies (one shown). Colors and letters refer to founders as indicated at the top of the image. Colored bars in the middle depict the composition of a single diploid chromosome throughout the left branch of the breeding funnel. At G₀ eight maize inbred lines are crossed in a half-diallel design to all possible hybrids. The 28 two-way hybrids (G₁) are permuted into different funnels, each producing an MM subfamily. The two-way hybrids with no founders in common are crossed for a total of 210 individual entries (G₂) later pooled into 70 four-way collections having the same founder alleles in different cis combinations. Four-way pools are crossed with their complement, establishing the eight-way progenitors (G₃). About 250 seeds from each eight-way progenitor are randomly chosen and sown establishing the MM lines. Each of at least 50 lines per subfamily is advanced through single seed descent (SSD) up to F₆. The genomic composition based on haplotype reconstruction of MM line 35_5 is shown at the bottom