Hindawi Publishing Corporation Journal of Botany Volume 2010, Article ID 742307, 13 pages doi:10.1155/2010/742307 Research Article Phylogenetic Relationships of Tetraploid AB-Genome Avena Species Evaluated by Means of Cytogenetic (C-Banding and FISH) and RAPD Analyses E. D. Badaeva, 1, 2 O. Yu. Shelukhina, 2 S. V. Goryunova, 2 I. G. Loskutov, 3 and V. A. Pukhalskiy 2 1 Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov str. 32, Moscow 119991, Russia 2 N.I. Vavilov Institute of General Genetics, Russian Academy of Sciences, Gubkin str. 3, Moscow 119991, Russia 3 N.I. Vavilov Institute of Plant Industry (VIR), Russian Academy of Agricultural Sciences, Bolshaya Morskaya str. 44, St. Petersburg 190000, Russia Correspondence should be addressed to E. D. Badaeva, katerinabadaeva@gmail.com Received 10 December 2009; Revised 11 February 2010; Accepted 15 March 2010 Academic Editor: Kang Chong Copyright © 2010 E. D. Badaeva et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 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. 1. Introduction Tetraploid oats are subdivided into four groups on the basis of karyotype structure and meiotic analysis of interspecific hybrids. We have focused on the two groups. The first of these has an AB-genome composition and includes A. bar- bata Pott., A. vaviloviana Mordv., and A. abyssinica Hochst. [1]. These three species hybridize with each other as well as with other Avena L. species, with the exception of those possessing the C-genome [2]. Some authors believe that this group originated through chromosome duplication of the As-genome diploid progenitor (possibly, A. hirtula Lagas. or A. wiestii Steud.)[3–6] and accordingly, the B-genome is a product of modification of the A-genome [7]. Therefore, the genome formula AA ′ was suggested for this group [8–10]. Another possibility is that the AB-genome oats are allopolyploids originated from hybridization of two different A-genome species, and therefore, the A and B genomes are genetically distinct [1, 11]. This assumption was confirmed by the results of molecular and cytogenetic analyses. They showed that the DNA sequence pAs120a, which is charac- teristic of the As-and Al-genome diploids, is hybridized only on the A-genome chromosomes, but not on the B-genome chromosomes of A. barbata and A. vaviloviana as well as on the chromosomes of A. canariensis and A. damascena [12]. The second group includes a single species, A. agadiriana Baum et Fedak. First, it was found during examination of a collection of the diploid A. canariensis, and based on morphological similarity this species was regarded as the progenitor of A. agadiriana. However, analysis of chromosome pairing in hybrids, which showed that at least four translocations are required for the formation of the multivalent associations in hybrids contradicted this suggestion [13]. Furthermore, the natural areas of these species do not overlap [14, 15].