Submitted to: Plant Genetic Resources: Characterization and Utilization
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/23/2008
Publication Date: 6/16/2008
Citation: Donnelly, L.M., M.M. Jenderek J.P. Prince, P.A. Reeves A. Brown and R.M. Hannan. 2008. Genetic diversity in the USDA Limnanthes germplasm collection assessed by simple sequence repeats. Plant Genetic Resources: Characterization and Utilization 1:33-41. Interpretive Summary: Meadowfoam (Limnanthes sp.) has attracted attention for industrial use due to unique characteristics of the seed oil. Wild populations of the plants showed variability in seed yield and oil content. The United State Department of Agriculture, Agricultural Research Service, National Plant Germplasm System (USDA-ARS-NPGS) maintains a meadowfoam germplasm collection. The diversity of the collection was evaluated by molecular markers. The markers differentiated all accessions, indicating that all accessions were unique, and that the USDA Limnanthes germplasm collection is genetically diverse, contributes to the conservation of the Limnanthes gene pool and is a suitable source of germplasm for the crop improvement.
Technical Abstract: The genus Limnanthes, also known as meadowfoam, has attracted attention for industrial use due to the unique characteristics of its seed oil. Samples from wild populations showed variability in agronomically important traits involved in seed oil yield, warranting the establishment and continued development of a germplasm collection. The level of genetic diversity within the United States Department of Agriculture, Agriculture Research Service, National Plant Germplasm System (USDA-ARS-NPGS) Limnanthes collection was evaluated using 15 simple sequence repeat (SSR) markers across 65 accessions representing 7 species and 17 subspecies. Parsimony analysis separated the accessions into two main groups, with little resolution within groups. These two groups were confirmed using neighbor-joining analysis and principal coordinate analysis. Accessions identified as L. floccosa and L. gracilis were found by morphological traits in both groups. The low resolution of the dendrograms within groups and the absence of species monophyly may be evidence for gene flow among Limnanthes species in the wild. SSR marker variation suggests that the Limnanthes germplasm collection is genetically diverse and therefore contributes to the conservation of the wild Limnanthes gene pool.