Genetic Risk Assessment of a Threatened Remnant Population of Hairy Prairie-Clover (Dalea villosa var. villosa) in the Canadian Prairie

Abstract: Hairy prairie-clover [Dalea villosa (Nutt.) Spreng. var. villosa] is a threatened Canadian wildflower. To facilitate the efforts of conserving this threatened plant, amplified fragment length polymorphism (AFLP) technique was applied to assess genetic diversity in a remnant hairy prairie-clover population in the Canadian Prairie. Three AFLP primer pairs were employed to genotype 610 individual plants from the population and 15 plants from a North Dakota composite population, and 100 polymorphic AFLP bands were analyzed. The assayed plants displayed 23% AFLP variation present between the remnant population and the North Dakota composite population, but maintained a high level (91%) of AFLP variation within patches of the remnant population. The individual genetic distinctiveness measured by average AFLP dissimilarity was positively associated with latitude and negatively with elevation. The among-patch AFLP variation was significantly related to inter-patch distance, indicating local genetic differentiation within the remnant population. However, the proportions of within-patch AFLP variation were not associated with any patch characteristics assessed (i.e., patch size, perimeter, nearest neighbor distance, mean inter-patch distance). No fine-scale genetic structure was found within three large patches, suggesting little genetic correlations present for plants five meters apart. Some genetically distinctive and diverse patches were also identified. These findings indicate that the genetic risk of the remnant hairy prairie-clover population in the Canadian Prairie is low.