Fig. 1.

Phylogenetic analysis of (A) nonnative (panicoid) and (B) native (pooid) rDNA ITS sequences. (A) The numbers inserted above and below the branches refer to the Bayesian posterior probabilities and the bootstrap values for maximum parsimony, respectively; –a and –b are variants of the same rDNA subtype, and –dir indicates a direct sequence of the respective rDNA type. Yellow circles including the numbers 1–9 indicate subclades referred to in the text and Table S4. Inset reports a summary of the distribution of panicoid rDNA (corresponding to five genera) across Hordeum, Pseudoroegneria, and Elymus species/accessions. (B) The New World species contain two rDNA loci (24). The dating of the nodes follows (25). H, Xu, Xa, and I are genome designators (26).