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 mol ecular study of phylogenetic relationships among 28 Elymus species. Tw o wild Hordeum species (H genome), two Pseudoroegneria species (S geno me), Agropyron cristatum (P genome), and Australopyrum velutinum (W ge nome) were included as genomic representatives for the genomes that su pposedly were involved in the evolution of the genus Elymus. Our resul ts are essentially congruent with the genomic classification system. T his study demonstrates that Elymus is not a monophyletic genus. Based on an analysis of Southern blot hybridization we could discriminate be tween SY and SH species owing to the strong specific hybridization pat tern of the H genome. Hexaploid SYH species gave a hybridization patte rn 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 unk nown genomic constitution. Elymus erianthus had a hybridization patter n distinctly different from all other species in the investigation.