Cytogenetics of Elymus magellanicus and its intra- and inter-generic hybrids with Pseudoroegneria spicata, Hordeum violaceum, E. trachycaulus, E. lanceolatus, and E. glaucus (Poaceae: Triticeae).

This paper describes the cytogenetics of the South American grass Elymus magellanicus (2n = 4x = 28) and its inter- and intra-generic hybrids with North American Pseudoroegneria spicata (2n = 2x = 14; SS), Iranian Hordeum violaceum (2n = 2x = 14; HH), and North American E. trachycaulus (2n = 4x = 28; SSHH), E. lanceolatus (2n = 4x = 28; SSHH), and E. glaucus (2n = 4x = 28; SSHH). Chromosome pairing in the F1 hybrid of E. magellanicus x P. spicata (2n = 3x = 21) averaged 4.09 bivalents per cell. Bivalent frequencies in the E. magellanicus x H. violaceum (2n = 3x = 21) averaged 4.86 bivalents per cell. Bivalent formation (frequencies) in hybrids between North and South American tetraploids averaged 11.42 in E. magellanicus x E. trachycaulus, 13.02 in E. magellanicus x E. lanceolatus, and 10.91 in E. magellanicus x E. glaucus. Meiotic data demonstrated that E. magellanicus is an allotetraploid having the same basic genomes (SSHH) as North American E. trachycaulus, E. lanceolatus, and E. glaucus.