ORIGIN AND EVOLUTION IN THE GENUS AVENA - IMPLICATIONS IN THE PLANT-BREEDING

Oat originated in Asia Minor or North Africa. It developed as a second -degree culture at North and West Europe, as an invader plant in seaso n main cultures as wheat and barley. The Avena species have three degr ees of ploidia: diploids (2n = 2x = 14), tetraploids (2n = 4x = 28) an d hexaploids (2n = 6x = 42), all having regular meiosis. Inside each d egree of ploidia there are cultivated forms which survive only under h uman care. Phylogenetic relations between Avena species are not comple tely stablished. Autopolyploidy, segmental alopolyploidy, as well as s tructural changes in chromosomes seem to have had relevant contributio n in the evolution of this genus. This review presents a synopsis of t he present knowledge about relations between the different species of Avena.