C-BANDING VARIATION IN THE MOROCCAN OAT SPECIES AVENA-AGADIRIANA (2N=4X=28)

The C-banding technique was used to describe the chromosomes of a rela tively recently-discovered Moroccan oat species, Avena agadiriana (2n = 4x = 28). A substantial amount of polymorphism for arm ratios and C- banding patterns was observed among five accessions of this species. H owever a common set of ten putatively homologous chromosomes was ident ifiable among the five accessions. The chromosomes of A. agadiriana do not closely match those of any of the previously described diploid or tetraploid oat species in terms of their arm ratios and C-banding pat terns. However, their overall C-banded appearance generally resembles the A/B/D groups of chromosomes of Avena species, rather than the more hetrochromatic C genomes. Implications of these findings in terms of chromosome evolution in the genus Avena are discussed.