Fig. 1

Graphical display of the results of the Structure analyses. a1) Proportions of ancestry of 1859 unique diploid apple genotypes for K = 3 groups inferred with Structure v.2.3.4 software [67]. Each genotype is represented by a vertical bar partitioned into K = 3 segments representing the estimated membership fraction in three groups. The three groups are depicted using the following color codes: Red = group K1; Blue = group K2; Green = group K3. a2) Proportions of ancestry of the same 1859 genotypes following a nested Structure analysis within each previously defined group. For K1 and K3 three subgroups are shown and for K2 two subgroups are shown. Each genotype is represented by a vertical bar partitioned into K = 2 or 3 subgroups representing the estimated membership fraction in each subgroup. Genotypes are presented in the same order than in a1. The subgroups are depicted using the following color codes: light Pink = K1.1; Purple = K1.2; dark Pink = K1.3; light Blue = K2.1; dark Blue = K2.2; fluorescent Green = K3.1; dark Green = K3.2; light Green = K3.3. b) Proportions of ancestry of 1653 unique diploid apple genotypes with known European region of origin for K = 3 groups inferred with the same Structure analysis as in a. The genotypes are sorted according to their European region of origin (North + East, West, and South)