FIGURE 4.

Neighbor-joining trees illustrating phylogenetic relationships among the 782 B. napus samples. Both cladograms were mid-point rooted. The A subgenome (A) and the C subgenome (B) show different topologies. In the A subgenome, most winter Asia samples are located outside the clades containing winter Europe and spring samples. This indicates that the A subgenome has a larger proportion of SNPs that are WA-specific (i.e., not found in other subpopulations). In contrast, WE samples tend to have a more basal location in the neighbor-joining tree for the C subgenome.