Population history, genetic variation and conservation status of European white elm (Ulmus laevis Pall.) in Poland

ContextThe most severe threat to elms is the loss of their natural habitat under the pressures of agricultural and forestry activities as well as urbanization pressures. For the last hundred years, reductions in European white elm populations as well as populations of other elm species have also been caused by Dutch elm disease (DED). Previous studies have indicated a low level of genetic variation in European white elms. However, in Poland, the genetic resources and demographic history of U. laevis populations remain poorly recognized.AimsHere, we present the first study in which the genetic resources of U. laevis in Poland were identified and characterized. Additionally, tests were performed to determine the bottleneck signatures and effective population sizes of the examined populations.MethodsPolymorphism was analysed using a set of six nuclear microsatellite markers (nSSRs) for 1 672 individuals from 41 populations throughout the species range in Poland.Results1) A low level of genetic variation was estimated. 2) Low genetic differentiation and lack of population structuring were identified. 3) Evidence of demographic processes was found.ConclusionWe speculated that the loss of genetic diversity of U. laevis probably occurred in their refugia or shortly after their postglacial recolonization. This loss may have been affected by past DED pandemics similar to those seen at present.The attached files provides the genetic data of analyzed white elm individuals from the 41 populations of the species from Poland obtained with the use of six microsatellite markers.