A study of 28 Elymus species using repetitive DNA sequences.

Four repetitive DNA sequences cloned from the barley (Hordeum vulgare) genome and common for different Triticeae species were used for a molecular study of phylogenetic relationships among 28 Elymus species. Two wild Hordeum species (H genome), two Pseudoroegneria species (S genome), Agropyron cristatum (P genome), and Australopyrum velutinum (W genome) were included as genomic representatives for the genomes that supposedly were involved in the evolution of the genus Elymus. Our results are essentially congruent with the genomic classification system. This study demonstrates that Elymus is not a monophyletic genus. Based on an analysis of Southern blot hybridization we could discriminate between SY and SH species owing to the strong specific hybridization pattern of the H genome. Hexaploid SYH species gave a hybridization pattern similar to SH species for the same reason. The results support the genomic composition of Elymus batalinii as SYP and also indicated the presence of at least one H genome in Elymus enysii with a hitherto unknown genomic constitution. Elymus erianthus had a hybridization pattern distinctly different from all other species in the investigation. Key words : Elymus, RFLP, phylogeny, repetitive DNA.