Research Advances on Systematics of Avena (Pooideae, Poaceae)

Abstract:

Advances in taxonomy, systematics, and polyploid origins of Avena L. (Pooideae, Poaceae) were reviewed. The key issues in systematics studies of Avena included: the debate on phylogenetic position of Avena in the Avena group; the absence of conclusive evidence for the circumscription of Avena, especially for A. macrostachya Bal. ex Cass. & Dur.; the unresolved phylogenetic relationships of major lineages in Avena; the considerable controversy about the genomic origins of hexaploid cultivated oats (i.e., A. nuda L. and A. sativa L.); and the paucity of accurate estimation of divergence time of Avena. The controversies on the genomic origins of hexaploid cultivated oats are rooted in the absence of accurate understanding for the divergence of A, C, and D genomes. The comprehensive investigation of molecular phylogeny, cytogenetics, palaeogeology, and palaeoclimatology may provide compelling evidence for the polyploid origins and the divergence histories of Avena, and it is significance for deeply utilizing the core germplasm resources of wild relatives of cereal crops.

Key words:Avena;Systematics;Polyploid origins;Advances