Genetic Variation for Dry Matter Yield, Forage Quality, and Seed Traits Among the Half-Sib Progeny of Nine Orchardgrass Germplasm Populations

A potential strategy to address the lack of success of North American orchardgrass (Dactylis glomerata L.) breeding programs to increase forage yield and other agronomic traits is the incorporation of novel sources of germplasm. In an attempt to identify novel orchardgrass germplasm sources with agronomic potential, the study described herein characterized 162 half-sib families (HSFs) from six orchardgrass germplasm populations and three orchardgrass cultivars. Study conditions were Millville, UT, and Rexburg, ID, field sites with data collection from 2008 to 2010. The genotype × location interaction variance differed from zero for dry matter yield, crude protein, in vitro true digestibility (IVTD), neutral detergent fiber, and seed weight. Within location broad-sense heritability differed for all traits at both locations (0.36 ±0.10 to 0.77 ±0.03) except IVTD at Rexburg. For each trait there were HSFs that possessed values similar to or better than the included check cultivars (CCs). Additionally, in several instances the mean phenotype of the HSFs from a specific family was better than the phenotype of the corresponding parental population and/or the mean phenotype of the CCs. Overall, for each trait there existed sufficient genetic variation to develop an elite orchardgrass breeding program for irrigated conditions.