Genetic diversity in the USDA Limnanthes germplasm collection assessed by simple sequence repeats

The genus Limnanthes (Limnanthaceae), 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 62 accessions representing 7 species. Parsimony analysis separated the accessions into two main groups consistent with the traditional taxonomic sections Inflexae and Reflexae, but there was little resolution within groups. These two groups were confirmed using neighbour-joining analysis and principal coordinate analysis. SSR marker variation suggests that the Limnanthes germplasm collection is genetically diverse and the accessions within the species likely contain novel alleles, and therefore the collection contributes to the conservation of the wild Limnanthes gene pool.