ARS | Publication request: Transferability of Orchardgrass (Dactylis Glomerata) SSR Primers and Genetic Diversity of Orchardgrass Subspecies

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 1, 2010
Publication Date: March 15, 2010
Citation: Bushman, B.S., Larson, S.R., Robins, J.G., Jensen, K.B. 2010. Transferability of Orchardgrass (Dactylis Glomerata) SSR Primers and Genetic Diversity of Orchardgrass Subspecies. MBFT, March 15-19, Buenos Aires, Argentina. Meeting Abstract.

Technical Abstract: Orchardgrass (Dactylis glomerata) is one of the most abundant forage grasses used for hay production and grazing. It has high biomass, but its water soluble carbohydrate levels and winter-hardiness tend to be intermediate between tall fescue and perennial ryegrass. As an autotetraploid, little is known about the genome of orchardgrass or the relationship of cultivars to the diploid and tetraploid exotic subspecies. As a near relative to both tall fescue and perennial ryegrass, orchardgrass comparative genomics can also have broader application than just the species level. In this study, we report the development and annotation of a large EST library from several orchardgrass varieties, tissues, and treatments. Over 17,000 unigenes were identified, with a high number of hits to putative orthologous sequences in other major forage and cereal grasses. SSR markers (1,196) were designed from ESTs and tested in a wide sampling of orchardgrass, mapping parents in perennial ryegrass, and potential mapping parents in tall fescue. A panel of 33 SSR primers was chosen for orchardgrass population genetic analysis, which includes markers predicted to map throughout the orchardgrass genome. These SSR markers were used to test the relationship of three varieties to 15 diploid subspecies, wherein the subspecies aschersoniana and lobata were found to be the closest relatives to cv 'Potomac', 'Paiute', and 'Latar.'