A repeated sequence probe for the C genome in Avena (Oats).

The genus Avena consists of at least 23 species composed of three ploidy levels. Cytogenetic analysis has characterised four distinct karyotypes. These are the A, B, C and D genomes. We have isolated a repeated sequence clone that can be used for the detection of the C genome in Avena by filter hybridization techniques. This clone, termed RS-1, is a genomic DNA clone containing at least one highly repeated sequence that is abundant in Avena species containing the C genome. This sequence or a related sequence is also present, but at much reduced levels, in species that do not contain the C genome. Because of its abundance and the characteristic Southern blot pattern, we have termed this clone a C genome specific clone. We have also done similar analysis of the Avena genus using a rDNA clone from wheat. The results of these experiments demonstrate that clearly definable C genome-specific markers can be identified with both probes. These molecular probes can be useful in studying the genomic relationships of Avena and can provide some clues as to the origin of the cultivated Avena species. These results can, therefore, provide breeders with directions for the efficient transfer of desirable traits of wild Avena species into commencal varieties.