Fig. 2

Genomic characteristics and phylogenetic relationships. a Simplified Bayesian ITS + matK phylogeny with representative species of different lineages and groups. The A. evenia, A. afraspera and BRH (Bakerophyton-Rueppelia-Humularia) clades are represented by black triangles and the polytomy is depicted in bold. Chromosome numbers are indicated in brackets. b Phylogenetic relationships based on the combination of 4 concatenated nuclear low-copy genes (CYP1, eif1a, SuSy and TIP1;1 genes detailed in Additional file 8: Figure S5). Diploid species (2n = 20) are in blue, polyploid species (2n ≥ 28) in black. The A and B subgenomes of the polyploid taxa are delineated by red and green boxes in dashed lines, respectively. Nodes with a posterior probability inferior to 0.5 were collapsed into polytomies. Posterior probability above 0.5 are indicated at every node. c The one-allopolyploidation hypothesis (N1-best) obtained with the phylogenetic network analysis based on the T2 tree with reticulations in blue (detailed in Additional file 10: Figure S7)