Unraveling the evolutionary dynamics of ancient and recent polyploidization events in Avena (Poaceae)

• DOI: 10.1038/srep41944
• Publication Date: 2017-02-03T11:28:13Z
• Authors: Qing Liu; Lei Lin; Xiangying Zhou; Paul M. Peterson; Jun Wen
• Keywords: Avena; Reticulate evolution; Lineage (genetic); Molecular clock; Polyploid; Mediterranean Basin

Abstract Understanding the diversification of polyploid crops in circum-Mediterranean region is a challenging issue evolutionary biology. Sequence data three nuclear genes and plastid DNA fragments from 109 accessions Avena L. (Poaceae) outgroups were used for maximum likelihood Bayesian analyses. The evolution cultivated oat ( sativa L.) its close relatives was inferred to have involved ancient allotetraploidy subsequent recent allohexaploidy events. crown ages two infrageneric lineages sect. Ventricosa Baum ex Romero-Zarco ) estimated be early middle Miocene, A. dated late Miocene Pliocene. These periods coincided with mild seasonal climatic contrasts Mediterranean climate established Basin. Our results suggest that polyploidy, lineage divergence, complex reticulate occurred , exemplifying long-term persistence tetraploids multiple origins hexaploids related paleoclimatic oscillations during Miocene-Pliocene interval region. This newly-resolved phylogenetic framework represents major step forward understanding origin oat.