Cryptic genetic subdivision in the San Benito evening primrose (Camissonia benitensis)

Abstract

When rare plants are distributed across a range of habitats, ecotypic differentiation may arise requiring customized conservation measures. The rate of local adaptation may be accelerated in complex landscapes with numerous physical barriers to gene flow. In such cases, examining the distribution of genetic diversity is essential in determining conservation management units. We investigated the distribution of genetic diversity in the federally threatened Camissonia benitensis (Onagraceae), which grows in two distinct serpentine habitats across several watersheds in San Benito, Fresno, and Monterey Cos., CA, USA. We compared genetic diversity with that of its two widespread relatives, C. contorta and C. strigulosa, and examined the potential for hybridization with the latter species. Genotyping results using seven heterospecific microsatellite markers indicate that differentiation between habitat types was weak (F ST = 0.0433) and in an AMOVA analysis, there was no significant partitioning of molecular variation between habitats. Watersheds accounted for 11.6 % of the molecular variation (pairwise F ST = 0.1823-0.4275). Three cryptic genetic clusters were identified by InStruct and STRUC-TURE that do not correlate with habitat or watershed. C. benitensis exhibits 5-119 higher inbreeding levels and 0.549 lower genetic diversity in comparison to its close relatives. We found no evidence of hybridization between C. benitensis and C. strigulosa. To maximize conservation of the limited amount of genetic diversity in C. benitensis, we recommend mixing seed representing the three cryptic genetic clusters across the species' geographic range when establishing new populations.

Adaptation and divergence in edaphic specialists and generalists: serpentine soil endemics in the California flora occur in barer serpentine habitats with lower soil calcium levels than serpentine tolerators

“… Citations used to determine serpentine status and sister taxa relationships: 1 Personal observation, 2 Safford et al., ; 3 Macnair and Gardner, ; 4 Anacker et al., ; 5 Spencer and Porter, ; 6 Baldwin et al., ; 7 Gottlieb and Weeden, ; 8 Green, ; 9 Baldwin, , 10 Baldwin et al., , 11 Dick et al., . …”

Microsatellite primers forCamissoniopsis cheiranthifolia(Onagraceae) and cross‐amplification in related species

“…Gray, and E. crassifolius (Greene) W. L. Wagner & Hoch, and successful amplification occurred for 17, 15, nine, and nine loci, respectively. Dick et al (2014) tested 16 of these 24 loci in the serpentine endemic Camissonia benitensis P. H. Raven and its two widespread congeners C. strigulosa (Fisch. & C. A.…”

“… b Amplification failures (Failed) and loci that were not tested in some species (NT) are indicated. c Data for the three species of Camissonia are from Dick et al (2014) . d These primers amplified two non-overlapping variable regions in the species indicated, so two fragment ranges are provided.…”

Genome skimming and microsatellite analysis reveal contrasting patterns of genetic diversity in a rare sandhill endemic (Erysimum teretifolium, Brassicaceae)

“…The distribution of genetic diversity was assessed with an analysis of molecular variance (AMOVA) and population genetic subdivision (F ST ) in Arlequin v3.5 [48]. For AMOVA, we used the restriction site model and compared the partitioning of genetic diversity within and among populations as well as among the genetic clusters identified by Structure [49]. For genetic subdivision, we calculated pairwise F ST values between all eight ERTE populations.…”