Tracing the phylogeny of the hexaploid oat Avena sativa with satellite DNAs

The genus Avena contains 30 different species from diploid through tetraplo id to hexaploid with different genome compositions. Research regarding the origin of the different genomes in the polyploid species has been inconclus ive. The objectives of this research were to investigate the phylogenetic r elationships of the Arena species by means of polymorphisms in satellite, m inisatellite, and microsatellite DNA. A satellite DNA sequence, ASS49, was isolated from a microsatellite-enriched library of the hexaploid oat Avena sativa L. Southern hybridization showed that ASS49 was a species-specific r ather than a genome-specific satellite, ASS49 was able to distinguish speci es that may be the diploid and tetraploid progenitors of hexaploid oat. The phylogenetic relationship of Avena species was further investigated using 40 microsatellite and four minisatellite primers. These results appeared to support the findings with ASS49, It appears that the Acgenome diploid spec ies (A. canariensis Baum Raj. et Samp.) is the progenitor and A-genome dono r of the hexaploid oat rather than the generally believed As-genome species (A, strigosa Schreber). Instead, A. strigosa appears to be a member of a s eparate lineage of diploid and tetraploid species including the tetraploid species A. abyssinica Hochst.