Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/30/2006
Publication Date: 5/31/2007
Citation: Bushman, B.S., Larson, S.R., Peel, M., Pfrender, M.E. 2007. Population Structure and Genetic Diversity in North American Hedysarum Boreale Nutt. (Hedysare: Fabaceae). Crop Science.
Interpretive Summary: The Great Basin Native Plant Selection and Increase Project funded this experiment to show relationships among and within Hedysarum boreale accessions, so that diversity and population structure could be included in decision making processes of incipient H. boreale plant breeding programs. This study characterized genetic diversity and population structure of 17 H. boreale accessions with neutral AFLP markers. We found high levels of genetic diversity within all accessions, but Eastern Utah accessions marginally the most diverse. All populations were distinct following an isolation-by-distance pattern, and two groups of accessions were identified in Eastern and Western Utah. Our results indicate that plant breeding programs that consider genetic diversity should include H. boreale plants from both the Eastern and Western Utah groups.
Technical Abstract: Hedysarum boreale Nutt. is a perennial legume native to Western North America, with robust foliage in the late spring season. Due to its wide native range and value as a forage and nitrogen fixer, H. boreale is of interest for rangeland revegetation and production. Seed cost has been a major obstacle for utilization of H. boreale, primarily due to shattering and unreliable seed production, such that a need for improved germplasm exists. This study was conducted to characterize genetic relationships of H. boreale accessions, so germplasm development efforts will have information necessary to maintain a broad genetic base within improved germplasm. Amplified Fragment Length Polymorphism (AFLP) markers were used on 17 available accessions from Utah, Idaho, Colorado, and Alaska, USA. Seventy percent of the total genetic variation was found within accessions, yet each accession showed significant isolation by distance. Genetic diversity within accessions was greatest in sites located in Eastern Utah. The sole cultivar, 'TIMP', had slightly greater genetic diversity than a collection made from the same site approximately 20 years later. Two groups of meta-populations were identified in Utah, separated longitudinally approximately along the Wasatch mountain range.