Characterization of Orchardgrass Germplasm Reso-urces for Improved Agronomic Performance and Animal Production

摘要

Orchardgrass (Dactylis glomerata) is a cool -season forage grass that is used in temperate areas world -wide. The objective of this study was to identify new sources of germplasm with high levels of genetic variation and agronomic performance for use in an applied orchardgrass breeding and genetics program. Nine orchardgrass germplasm sources were used in two field evaluations to characterize half-sib families for agronomic traits including biomass production, maturity, and phenology. With the exceptions of culm width and the number of nodes per spikelet, we identified significant genetic variation for the remaining biomass production and morphological/phonological traits. We also found that the traits possessed generally low to moderate heritability among these germplasm sources (h2=0 to 0. 75). Of note, we found the germplasm from China, Japan, and Russia possessed biomass production potential approaching 10 Mg ha"1 and identified these sources as important additions to our breeding program. We also constructed an EST library from tissue collected from a collection of orchardgrass cultivars. We now use the library to identify markers for genetic map construction and gene identification.