Tree Genetics & Genomes

, Volume 6, Issue 3, pp 439–450

Phylogeography of Populus alba (L.) and Populus tremula (L.) in Central Europe: secondary contact and hybridisation during recolonisation from disconnected refugia

Original Paper

DOI: 10.1007/s11295-009-0262-5

Cite this article as:
Fussi, B., Lexer, C. & Heinze, B. Tree Genetics & Genomes (2010) 6: 439. doi:10.1007/s11295-009-0262-5

Abstract

The central aim of this paper is to clarify the picture of postglacial recolonisation and the reconstruction of refugia of Populus alba (L.) and Populus tremula (L.) in the light of hybridisation of the two species. We focussed our study on Central and Southeastern Europe including reference samples from Spain, Sweden and Northern Africa.We investigated 414 individuals of 26 populations using restriction fragment length polymorphisms (PCR-RFLPs) in six maternally inherited chloroplast markers. Altogether, 57 haplotypes were analysed of which four indicated hybridisation events in the past. Phylogeographic structure was found for P. alba with low diversity in Eastern Europe versus high diversity in Italy and Central Europe. A lack of phylogeographic structure was assessed for P. tremula as expected for a boreal forest tree, and diversity was evenly distributed in the studied populations. Two main refugia were identified for P. alba in Italy and Romania. A previously described hybrid zone between species in Central Europe turned out also to be a zone of contact between southern and eastern chloroplast lineages in P. alba. In contrast, P. tremula recolonised its present habitats in Central Europe from several refugia near the former ice cap. We assume separate disconnected refugia for P. alba and P. tremula and suggest an immigration scenario involving the mixing of colonisation routes and interspecific introgression to be responsible for the observed patterns.

Keywords

Postglacial recolonisationHybridisationPCR-RFLPscpDNAPopulus albaPopulus tremula

Supplementary material

11295_2009_262_MOESM1_ESM.pdf (108 kb)
Appendix S1Sampling locations and number of haplotypes per population (PDF 107 kb)
11295_2009_262_MOESM2_ESM.pdf (38 kb)
Appendix S2Haplotype definition of eight variable fragments (PDF 37 kb)
11295_2009_262_MOESM3_ESM.pdf (488 kb)
Appendix S3Haplotype distribution in Europe and Northern Africa (PDF 487 kb)

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Barbara Fussi
    • 1
  • Christian Lexer
    • 2
  • Berthold Heinze
    • 1
  1. 1.Department of GeneticsFederal Research and Training Centre for Forests, Natural Hazards and LandscapeViennaAustria
  2. 2.Unit of Ecology and Evolution, Department of BiologyUniversity of FribourgFribourgSwitzerland