Phylogenetic Relationships of Tetraploid AB-Genome <i>Avena</i> Species Evaluated by Means of Cytogenetic (C-Banding and FISH) and RAPD Analyses

Abstract

Tetraploid oat species Avena abyssinica , A. vaviloviana , A. barbata , and A. agadiriana were studied using C-banding technique, in situ hybridization with the 45S and 5S rDNA probes, and RAPD analysis in comparison with the diploid species carrying different types of the A-genome ( A. wiestii , As; A. longiglumis , Al; A. canariensis , Ac; A. damascena , Ad, A. prostrata , Ap). The investigation confirmed that all four tetraploids belong to the same AB-genome group; however A. agadiriana occupies distinct position among others. The C-banding, FISH, and RAPD analyses showed that Avena abyssinica , A. vaviloviana , and A. barbata are very similar; most probably they originated from a common tetraploid ancestor as a result of minor translocations and alterations of C-banding polymorphism system. AB-genome species are closely related with the A-genome diploids, and an As-genome species may be regarded as the most probable donor of their A-genome. Although their second diploid progenitor has not been identified, it seems unlikely that it belongs to the As-genome group. The exact diploid progenitors of A. agadiriana have not been determined; however our results suggest that at least one of them could be related to A. damascena .