Principal coordinate analysis of 20 T. monococcum accessions based on 1041 DArT markers. The diagram shows the position of each accession in the space spanned by the first two coordinates of a relative Jaccard similarity matrix. The accession codes and susceptibility to take-all are inserted in the figure. Susceptibility to take-all is based on the field screening disease index scores reported in this study. Accessions were classified as susceptible (S), moderately resistant (MR), resistant (R), inconsistent performance in different field trials (I), and not tested in the field (NT).