High genetic diversity within island-like peripheral populations ofPedicularis sceptrum-carolinum, a species with a northern geographic distribution

Abstract

Isolated and island-like populations at the periphery of a geographic range of a given species are usually predicted to have low genetic diversity due to founder effect, habitat fragmentation, and bottleneck and/or inbreeding. As for parasitic plants, they may be more vulnerable to environmental and demographic stochasticities, habitat degradation, and genetic limitation because of their specialized life-history strategies depending on i.e. host plants. Pedicularis sceptrum-carolinum is a hemiparasitic species with a strongly fragmented geographic range in Eurasia whose small, isolated, island-like populations are scattered at the periphery of its geographic range. I studied its genetic diversity patterns at the western periphery of the species' range (Poland) using AFLP markers in order to unravel how isolation, population size and life-history traits (i.e. type of reproduction) influence its population genetic structure. Despite the geographic isolation among the four investigated populations (ca. 35–35...