ARS | Publication request: New Genomic Resources for Pasture and Range Grasses

Submitted to: Molecular Breeding of Forage and Turf Conference
Publication Type: Abstract Only
Publication Acceptance Date: June 1, 2007
Publication Date: July 1, 2007
Citation: Bushman, B.S., Larson, S.R., Wang, R., Mott, I.W. 2007. New Genomic Resources for Pasture and Range Grasses. Molecular Breeding of Forage and Turf Conference.

Technical Abstract: One of the initial requirements of utilizing genomic approaches in plant improvements is the availability of DNA sequence information. Toward the goal of generating sequence information for forage and pasture grasses, we are developing EST libraries from orchardgrass (Dactylis glomerata) and several Triticeae forage grasses (Pseudoroegneria spicata, Leymus spp., and Elymus spp.). Tissues collected from orchardgrass included water and salt stressed shoot and roots, etiolated seedlings, and low temperature acclimated crowns. From the Triticeae grasses, rhizome and tiller ends, water and salt stressed shoot and roots, and etiolated seedlings were collected. Library construction, sequencing, and bioinformatics were carried out through a cooperation with the University of Illinois W. M. Keck Center for Comparative and Functional Genomics. All EST libraries were normalized, tagged for identification by tissue, and sequenced from both the 5' and 3' ends in order to include the 3' untranslated regions (UTR). Average length of sequences was greater than 1 kb, and 8,000-11,000 unigenes were detected for the Triticeae libraries upon contig assembly. Approximately 1,400 SSRs were detected from the Pseudoroegneria library and 1,700 from the Leymus library. These SSR containing contigs/sigletons were aligned to rice chromosomes, and the predicted location of SSR markers has been validated for the Leymus library. Additional PCR primers designed from the 3' UTR regions contained higher degrees of polymorphism than SSRs. The orchardgrass library sequencing is not yet completed such that more data will be presented; and current and projected uses will also be discussed.