High genetic differentiation in marginal populations of European White Elm (Ulmus laevis)

Abstract

Studies on the amount of genetic variation in marginal populations and differentiation between them are essential for assessment of best gene conservation strategies and sampling schemes. Thirteen marginal populations of Ulmus laevis in southern Finland and one in Estonia were investigated for genetic variation in 20 allozyme loci. Population differentiation among Finnish stands was high, Fst = 0.290, and mean genetic diversity low, H e = 0.088. The differentiation follows the isolation-by-distance structure within the core of the distribution area (lake Vanajavesi). Fairly high frequency of recurrent genotypes was observed, but this did not have an influence on the genetic parameters. The observed genetic structure is consistent with the central-marginal hypothesis. In the light of the results, the Finnish gene conservation strategy for U. laevis seems to be on a sound basis.