Cover illustration: The inset cover image shows the grass Brachypodium distachyon and B. hybridum and, superimposed, a metaphase of the latter after multicolour fluorescence in situ hybridisation (mcFISH) with B. distachyon-originated BAC-based probes allowing identification of individual chromosomes. The Brachypodium genus is a useful model system for studying grass genome organisation and its key representative B. distachyon (n = 5, Bd genome) is well characterised at the cytogenetic and genomic level. Comparative chromosome mapping showed various and complex rearrangements including nested chromosome fusions and Robertsonian rearrangements that shaped the B. stacei (n = 10, Bs genome) and B. hybridum (n = 15, Bd+Bs), karyotypes. See Lusinska et al. p. 445–459.