Figure 7.

Principle coordinate analysis (PCA). Plot of PCA axes 1 and 2 based on Manhattan distance calculations for 134 oat varieties using 1295 non-redundant DArT marker loci. Oat varieties are identified by truncated entry names, which are preceded by two-letter codes indicating country of origin, and by additional codes if they are winter-types (W), fall-sown but winter grown (F), or naked (N). See Additional file 1 for full entry names and country of origin codes. Selected counties of origin are coloured blue (Brazil), red (Canada), pink (Great Britain), light-blue (Norway), yellow (Sweden), purple (USA), or green (USA-Fall/Winter).