R-genes conservation between duplicated blocks in grasses. (A) Illustration at the top of the grass ancestral genomes with n = 5 (A5, A7, A11, A8, A4) paleoduplicated into n = 12 (A1 to A12) defining 7 shared duplicated blocks (black arrows). The number of conserved R-genes (y-axis) between duplicated chromosomes (x-axis) in modern grasses is illustrated as box plots ( illustrates non-significant differences; illustrates significant differences based on permutation test with P-value < 0.05, see Methods section). Distribution pattern of conserved R-genes in modern chromosome pairs is shown in rice, Brachypodium, sorghum and maize. (B) Illustration of the correlation between the number of observed R-genes in cluster (x-axis) and the total number of conserved R-genes (y-axis) characterized in the sensitive (red dot and curve) and dominant (black dot and curve) chromosomal blocks.