Submitted to: Plant Genetic Resources
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 14, 2011
Publication Date: May 17, 2011
Citation: Mott, I.W., Larson, S.R., Bushman, B.S. 2011. Simple sequence repeat (SSR) markers for Elymus, Pseudoroegneria, and Pascopyrum species (Triticeae: Gramineae). Plant Genetic Resources. doi: 10.1017/S1479262111000694. Interpretive Summary: There are approximately 150 Elymus grass species in the Triticeae tribe in the grass family Poaceae. Elymus grasses show adaptation to many abiotic stresses and are important sources of forage and habitat for wildlife and livestock and are used in seeding and soil stabilization efforts on semi-arid wildlands. Molecular genetic resources such as DNA markers are very limited for this genus and have required the use of resources from other related plants. To facilitate plant identification, functional diversity studies, taxonomy, and comparative genetic mapping of Elymus species, we have identified and characterized 100 expressed sequence tagged Simple Sequence Repeat (SSR) markers derived from a Elymus wawawaiensis and Elymus lanceolatus cDNA library. These SSRs were tested on a panel of seven grass accessions/cultivars; five Elymus species, Pseudoroegneria spicata (Anatone bluebunch wheatgrass), and Pascopyrum smithii (Rosana western wheatgrass). The 100 SSRs produced 432 polymorphic bands with individual SSRs producing 0 to 8 bands per plant across all species. The data generated from these SSR markers were useful in grouping all plants to their respective accession/cultivars in a Neighbor Joining (NJ) phylogram. These 100 SSR markers have high species transferability and will be useful in studying Elymus, Pseudoroegneria, and Pascopyrum species.
Technical Abstract: The Triticeae tribe (Poaceae) includes several important cereal crops, cultivated forages, annual and perennial grass weeds, and ecologically diverse native North American grasses. Elymus L. is the largest and most complex genus in the Triticeae tribe with approximately 150 polyploid perennial grass species occurring worldwide. The genomic constitutions of approximately 40% Elymus species are unknown. Molecular markers are needed to facilitate genetic analysis of diversity and functional traits in these species. We have developed Simple Sequence Repeat (SSR) markers for use in Elymus based on Elymus Expressed Sequence Tag (EST) based. To test the polymorphic content and transferability of these markers, 100 SSR markers were tested on 84 plants representing seven North American Elymus species. These 100 SSRs produced 432 polymorphic bands, of which the 23 most polymorphic SSRs produced 142 bands and successfully separated all individuals into their respectiv accessions in a neighbor-joining phylogram. Genetic diversity within and among these seven accessions/cultivars is described. These SSR markers will be a useful tool for investing genetic diversity, genome constitutions, and molecular mapping in Elymus and other Triticeae grasses.