Phylogenetic investigation of Avena diploid species and the maternal genome donor of Avena polyploids

Abstract

AbstractWe investigated the species and genome relationships among 82 Avena accessions representing thirteen diploid species (A and C genomes), six tetraploids (AB and AC genomes) and four hexaploids (ACD genome) to infer the evolutionary pathways in Avena using the plastid matK gene and the trnL‐F region. The matK and trnL‐F sequences pointed to the A‐genome diploid species as maternal parents of the polyploid species. Furthermore, different A‐genome diploid species might have served as the A genome donor of several different polyploid species. The probable ancestor of most hexaploid species, of the AC‐genome tetraploids, and of the AB‐genome species A. agadiriana was A. wiestii (As genome). The likely donor of the other three AB‐ genome tetraploids was A. hirtula (also As genome) and A. damascena (Ad genome) appears to be the A genome donor of the hexaploid A. fatua. The A genome origin of A. fatua differs from that for the other hexaploid Avena species, which is different from the common assumption that the hexaploid species evolved from a single hexaploid ancestor followed by gain or loss of domestication genes. Thus, several separate maternal lineages might be involved in different polyploid species.