Genetic Variation for Agronomic Traits in Novel Orchardgrass Germplasm.

Orchardgrass (Dactylis glomerata) is one of the more important cool-season forage grasses for grazing and/or hay in the temperate regions of the world. Despite its and importance as a forage and long-standing breeding efforts aimed at orchardgrass improvement, there has been little gain for forage yield. To address the lack of gain, we initiated an orchardgrass breeding program using novel germplasm to explore the possibility of developing hybrid orchardgrass varieties to capitalize on heterosis to improve agronomic traits. Population hybrids and half-sib families were developed from nine population sources representing orchardgrass germplasm from various parts of the world. The hybrids and families were evaluated at two Intermountain West U.S. locations (Logan, UT and Rexburg, ID) from 2007-2009. Various agronomic traits were evaluated including phenology/morphology, maturity, biomass production, and forage quality. Substantial variation existed within these populations for each of these traits and some of the population hybrids exhibited high-parent heterosis. Based on these results a rigorous program aimed at semi-hybrid orchardgrass development will move forward at the ARS Forage and Range Research Laboratory in Logan, UT.