Genetic Variation for Morphology and Maturity Among the Half-Sib Progeny of Nine Orchardgrass Germplasm Populations.

Orchardgrass (Dactylis glomerata L.) acreage has declined compared to perennial ryegrass (Lolium perenne L.) and tall fescue (Festuca amndinacea Schreb.). With the intent of developing new sources of orchardgrass germplasm, 162 half-sib families from six orchardgrass germplasm populations and three orchardgrass cultivars were evaluated during 2008 for maturity and plant morphology at locations in Idaho and Utah. Genetic similarity of the populations was also characterized using simple sequence repeat markers. Genetic variation between families differed from zero for seven of the nine traits evaluated, with broad-sense heritability estimates ranging from 0.26 (flag leaf width) to 0.74 (maturity). For each trait that exhibited genetic variation, half-sib families were identified that possessed trait values similar to or more extreme than the values corresponding to the included commercial orchardgrass cultivars. Through principle component analysis, potential groupings of half-sib families with similar phenotypic characteristics were identified; for example, taller plants with earlier maturity. Therefore, germplasm could be targeted for development of improved orchardgrass with maturity and morphology suitable to specific management practices, such as short stature, narrow leaves, and late maturity for mixture with legumes. [ABSTRACT FROM AUTHOR]