The Western Prairie Fringed orchid, Platanthera praeclara, is a threatened and federally protected orchid which generally occurs in small, isolated populations due to habitat destruction. The restricted number of potential mates increases the probability of inbreeding and a subsequent inability of the orchids to adapt to a changing environment. The genetic structure and gene flow of P. praeclara populations are not well understood. We have designed a study using microsatellite markers to answer the following questions: What is the genetic structure of Western Prairie Fringed orchid populations in Minnesota and North Dakota? What is the level of gene flow among these populations? and What are the estimated levels of inbreeding within each population? We sampled eight populations in North Dakota and Minnesota in 2009 and 2010, as well as a population in Canada in 2010.
Results/Conclusions
In the 2009 populations we found there was no evidence of strong genetic structure among populations. However two centrally located populations were the most genetically distinct. These patterns may reflect the original seed dispersion patterns in the face of limited gene flow today.