Genetic diversity of Salixlapponum populations in Central Europe.

Jacek Urbaniak,Paweł Kwiatkowski,Paweł Pawlikowski

doi:10.3897/phytokeys.184.71641

Abstract

Salixlapponum is a cold-tolerant relict species in Europe that occurs in several sites, probably reflecting previous migration routes of S.lapponum during the Pleistocene. However, only a few data are available on the genetic structures of populations of S.lapponum. In this study, we use PCR-ISSR markers to investigate genetic variation in 19 European populations of S.lapponum L. AMOVA analysis shows that most of the variation (55.8%) occurs within populations; variability among groups accounts for 19.7%. An AMOVA analysis based on four groups determined by STRUCTURE analysis shows similar results: variability of 54.1% within the population and variability of 18.9% between the four population groups, based on geographic regions. Within individual geographic groups, which are characterised by the studied populations, the lowest variability (as well as the highest homogeneity) was found in populations located in Belarus. The obtained results are consistent with our expectations that the European Lowland could be a significant geographic barrier for gene flow over large geographic distances for S.lapponum. Both the Scandinavian and Belarusian populations, as well as those coming from NE Poland, are characterised by significant genetic distinctiveness. However, some populations from NE Poland and the Sudetes show similarities with populations from other geographic regions, indicating existing genetic relationships between them. Moreover, the results suggest a fairly clear division of the population into 4 emerging geographic regions, although separated by a geographical barrier: the Polish lowland, which forms part of the larger geographic unit known as the European Lowland.

Highlights

Quaternary glaciation, with numerous glaciations and deglaciations in Scandinavia and Central Europe, strongly influenced changes in the distributions of both specific plants and entire plant biomes
During the Ice Age, the tundra developed on a portion of the European Lowlands (Van Andel 2002; Birks and Willis 2008), where arctic and alpine plants grew on much wider territory than their current ranges
Molecular variance analysis (AMOVA) indicates that most of the genetic variation in two groups of populations: Sudetes vs. NE Poland and Belarus occurs within populations (55.8%), while the variability among the groups accounts for 19.7% (Table 2)

Summary

Introduction

Quaternary glaciation, with numerous glaciations and deglaciations in Scandinavia and Central Europe, strongly influenced changes in the distributions of both specific plants and entire plant biomes. During Pleistocene climatic fluctuations, numerous arctic plants migrated southward, where they commonly colonised habitats primarily in European mountain ranges; in some cases, they disappeared from these locations during warmer period called interglacials. Plant species that lived outside of refugia retreated northward or disappeared completely Under these conditions, gene flow and some isolated populations could occur in between migrating populations; these were commonly subjected to unfavourable genetic conditions such as a sharp reduction in population size due to environmental events, which reduced variation in the gene pool (known as a population bottleneck) or due to other changes in allele frequency, including genetic drift (Comes and Kadereit 1998; Hewitt 2004; Schönswetter et al 2005; Stewart et al 2010; Urbaniak et al 2019). Some papers that have examined the effect of spreading disjunctive plant populations have clearly reported its negative effect (Paun et al 2008)

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Conclusion