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Xerothermic species of the genus Campanula in Poland - a model for the phylogeographical assessment of reconstruction of post-glacial migration routes

Migration routes of the representatives of particular geographical and ecological groups (‘elements’) forming the contemporary Polish flora have been an object of botanical studies for more than a century. The present paper introduces a research project (being now carried out by the author) attempting to address this problem using phylogeographical approach (i.e. correlating present geographical distribution pattern with genetic relationships of populations) to confirm and/or correct reconstructions of the ‘steppic’ element migration routes, established by means of classical methods to date. As a model, four species of the genus Campanula (namely: C. sibirica, C. bononiensis, C. cervicaria and C. glomerata) were proposed, representing an ecological gradient (varied degree of the connection to dry and thermophilous habitats).

Abstract

Common ash (Fraxinus excelsior L.) has a widespread distribution throughout Europe, and Latvia is almost at the north eastern edge of the distribution range. In Europe, ash is threatened by ash dieback, a disease caused by the introduced ascomycete Hymenoscyphus fraxineus. Chloroplast and nuclear DNA markers have been used to study the genetic diversity and population structure of ash both in a broader pan-European context as well as in more restricted regions. Some of the markers analysed in these previously published reports were also utilised in this study, enabling comparisons of the genetic parameters calculated from the nuclear SSR marker data and of the haplotypes identified with the chloroplast markers. Analysis of chloroplast markers revealed one dominant haplotype in Latvian stands, which corresponds to the haplotype previously found in Eastern Europe and Scandinavia. A second haplotype, corresponding to a previously reported central European haplotype was found in all individuals from the Ķemeri stand, indicating that this stand was naturally established from introduced germplasm, which was planted in a neighbouring park. The nuclear SSR markers revealed low levels of differentiation of Latvian F. excelsior stands, probably due efficient pollen flow between stands. The analysis of both chloroplast and nuclear DNA markers has revealed different aspects of the structure and provenance of Latvian F. excelsior populations.

Abstract

Efficient use of any breeding resources requires a good understanding of the genetic value of the founder breeding materials for predicting the gain and diversity in future generations. This study evaluates the distribution of genetic variation and level of relatedness among and within nine breeding populations of Norway spruce for Northern Sweden using nuclear microsatellite markers. A sample set of 456 individuals selected from 140 stands were genotyped with 15 SSR loci. Over all loci each individual was identified with unique multilocus genotype. High genetic diversity (average He=0.820) and low population differentiation (FST=0.0087) characterized this material. Although low in FST, the two northernmost populations were clustered as a distinct group diverged from the central populations. The population differentiation pattern corresponds well with the post glacial migration history of Norway spruce and the current gene flow and human activity in the region. The average inbreeding coefficient was 0.084 after removal loci with high frequency of null alleles. The estimated relatedness of the trees gathered in the breeding populations was very low (average kinship coefficient 0.0077) and not structured. The high genetic variation and low and not structured relatedness between individuals found in the breeding populations confirm that the Norway spruce breeding stock for northern Sweden represent valuable genetic resources for both long-term breeding and conservation programs.

-49. SCHLARBAUM, S. E., R. P. ADAMS, W. T. BAGLEY and W. J. WAYNE (1982): Post-glacial migration pathwaya of Quercus rubra L., Northern Red Oaks, as indicated by regional genetic-variation patterns. Silvae genetica 31: 150-158. SCHMELZ, D. V. and A. A. LINDSEY (1965): Size class structure of old growth forests in Indiana. Forest Science 11: 258-264. SMALLWOOD, P. D., M. STEEL, A., E. RIBBENS and W. J. MCSHEA (1998): Detecting the effect of seed hoarders on the distribution of seedlings of tree species: Gray squirrels (Sciurus carolinensis) and oaks (Quercus) as a model system

use of RAPD analysis to study diversity in British black poplar ( Populus nigra L. subsp. betulifolia ( Pursh) W. Wettst., Salicaceae) in Great Britain. Watsonia 21:305-312 Cottrell JE, Krystufek V, Tabbener HE, Milner AD, Connolly T, Sing L (2005) Post-glacial migration of Populus nigra L.: lessons learnt from chloroplast DNA. Forest Ecol Manag 219:293-312 http://dx.doi.org/10.1016/j.foreco.2005.10.003 Degen B (2008) GDA_NT 2.0: Genetic data analysis and numerical tests. [last change 17.11.2015]. Available from bernd.degen@thuenen.de Du Q, Wang B, Wei Z, Zhang