Development of nuclear microsatellite loci for Pinus albicaulis Engelm. (Pinaceae), a conifer of conservation concern

PLoS One. 2018 Oct 18;13(10):e0205423. doi: 10.1371/journal.pone.0205423. eCollection 2018.

Abstract

Pinus albicaulis (whitebark pine) is a widely-distributed but rapidly declining high elevation western North American tree and a candidate for listing under the U.S. Endangered Species Act. Our objectives were to develop reliable nuclear microsatellite markers that can be used to assess within-population genetic diversity as well as seed and pollen migration dynamics, and to validate markers using two geographically proximal P. albicaulis populations. We identified 1,667 microsatellite-containing sequences from shotgun DNA libraries of P. albicaulis. Primer pairs were designed for 308 unique microsatellite-containing loci, and these were evaluated for PCR amplification success and segregation in a panel of diploid needle tissue. DNA was extracted with an SDS protocol, and primers were screened through gel electrophoresis. Microsatellites were genotyped through fluorescent primer fragment analysis. Ten novel and 13 transferred loci were found to be reproducible in analyses based on 20 foliage samples from each of two locations: Henderson Mountain, Custer Gallatin National Forest, Montana, and Mt. Washburn, Yellowstone National Park, Wyoming (USA). Transferred loci had higher numbers of alleles and expected heterozygosities than novel loci, but also revealed evidence for a higher frequency of null alleles. Eight of the 13 transferred loci deviated significantly from Hardy-Weinberg Equilibrium, and showed large positive FIS values that were likely inflated by null alleles. Mantel's tests of transferred and novel markers showed no correlation between genetic and geographic distances within or among the two sampled populations. AMOVA suggests that 91% of genetic variability occurs within populations and 9% between the two populations. Studies assessing genetic diversity using these microsatellite loci can help guide future management and restoration activities for P. albicaulis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Nucleus / genetics
  • Conservation of Natural Resources / methods*
  • DNA Primers / genetics
  • Endangered Species
  • Genetic Linkage
  • Genetics, Population
  • Microsatellite Repeats*
  • Pinus / genetics*
  • Pinus / physiology
  • Pollen / genetics
  • Pollen / physiology
  • Population Dynamics
  • Seeds / genetics
  • Seeds / physiology
  • United States

Substances

  • DNA Primers

Grants and funding

In-house funding from the University of Colorado Denver Office of Research Services to Diana F. Tomback and Assistant Professor A. Moisier (who had no role in this particular aspect of our research). This work was also supported by Wyoming Native Plant Society (http://www.wynps.org/) and U.S. Forest Service Pacific Northwest Region (https://www.fs.fed.us/wildflowers/regions/Pacific_Northwest/index.php). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.