Morphological characteristics of crested wheatgrass populations of diverse origin

In crested wheatgrass, the species Agropyron cristatum includes populations that are diploid and tetraploid, either naturally or artificially induced. The species Agropyron desertorum is tetraploid and there are culitvars that are hybrids between A. cristatum and A. desertorum. The goal of this study was to compare the morphology (height, crown width, tiller density, tiller weight and tiller angle) of populations from the two species and hybrids, including S9240, a recently developed colchicine induced tetraploid A. cristatum. Data were collected in 1999 and 2000 from several different sward-seeded and spaced-planted trials. The four tetraploid crested wheatgrasses (A. cristatum “Kirk” and “S9240”, A. desertorum “Nordan”, and A. desertorum × A. cristatum “CD-II”) were significantly (P < 0.05) taller, narrower in row width, and produced fewer, heavier tillers than the diploid A. cristatum “Parkway”. Among the tetraploid populations, S9240 was significantly (P < 0.05) taller and produced fewer tillers. S9240 also produced significantly (P < 0.05) heavier tillers than CD-II and Nordan, and also than Kirk, one year of two. Row widths were variable among populations, but S9240 generally produced a narrower crown than other populations. Key words: Crested wheatgrass, polyploidy, plant height, crown diameter, tiller characteristics