Fig. 2: Structure of the apple reference population.
From: The apple REFPOP—a reference population for genomics-assisted breeding in apple
a Unrooted neighbor-joining tree of the accession group, colors correspond to the legend in “b”. b Principal component analysis of the accession group with progeny group as supplementary individuals encircled with a normal confidence ellipse (constructed using a multivariate normal distribution, level 0.95). Plot of the first two principal components with their respective proportion of the total variance shown within brackets. c ADMIXTURE bar plot of the accession group for K = 14. Labels in plots “a” to “c” refer to the geographic origin of genotypes: ZAF (South Africa), JPN (Japan), ANZ (Australia and New Zealand), CAN (Canada), USA (United States of America), WCE (Western and Central Europe), NEE (Northern and Eastern Europe), SE (Southern Europe), SEE (Southeastern Europe), U (accessions of unknown geographic origin), and P representing the progeny group in plot “b”. In plot “c”, each group of genotypes with a common geographic origin is labeled at its right side
