Allopatric divergence and secondary contacts in Euphorbia spinosa L: Influence of climatic changes on the split of the s
- PDF / 608,950 Bytes
- 16 Pages / 595.276 x 790.866 pts Page_size
- 96 Downloads / 138 Views
ORIGINAL ARTICLE
Allopatric divergence and secondary contacts in Euphorbia spinosa L: Influence of climatic changes on the split of the species G. Zecca & G. Casazza & L. Minuto & M. Labra & F. Grassi
Received: 20 April 2011 / Accepted: 2 October 2011 / Published online: 20 October 2011 # Gesellschaft für Biologische Systematik 2011
Abstract Euphorbia spinosa, a perennial xerophilous shrub naturally distributed across the Italian peninsula, was selected for examination of the role of the Ligurian Alps and Apennines in glacial survival. The Italian Peninsula is considered to be one of the principal glacial refugia in Europe, but few plant population genetic and phylogeography studies have been undertaken in this region. The combined analysis of chloroplast and nuclear loci (ITS, cpSSR and ISSR) enabled us to detect extensive DNA variation and proved to be a very powerful tool for the reconstruction of the phylogeography. Molecular data support the hypothesis of a long-term separation of the Northwestern (Maritime Alps, Sardinia, Corsica, Northern Apennines) and Electronic supplementary material The online version of this article (doi:10.1007/s13127-011-0063-1) contains supplementary material, which is available to authorized users. G. Zecca : F. Grassi Botanical Garden, Department of Biology, Università degli studi di Milano, Via Celoria 26, Milan, Italy G. Casazza : L. Minuto DIP.TE.RIS, Università degli studi di Genova, Corso Dogali 1M, Genova, Italy M. Labra Department of Biosciences, Università degli studi di Milano-Bicocca, P. della Scienza 2, Milan, Italy F. Grassi (*) Botanical Garden of Milan, University of Milan, Via Celoria 26, 20133 Milan, Italy e-mail: [email protected]
Southeastern (Southern Apennines and Balkan area) lineages in glacial refugia. The existence of allopatrically fragmented lineages is most probably the result of isolation in different glacial refugia, possibly due to the Last Glacial Maximum cooling and the topographic complexity of the Italian peninsula. The most plausible hypothesis assumes the formation of two migration paths during more recent periods: the first one starting with southward migration and the second one moving northwards. The Central Apennines should be considered the confluence of migration routes radiating from separate refugia according to this hypothesis. Keywords Apennines . Glacial refugia . Haplotype . Admixture . Maritime alps . Multiple refugia
Introduction The Mediterranean climatic conditions emerged at the end of the Tertiary (Piacentian stage of Pliocene between 3.6 and 2.6 Myr) so the Mediterranean ecosystem can be considered ‘young’ with the majority of present-day species represented by colonizers of varying origins (Blondel and Aronson 1999). In particular, the Mediterranean flora is the result of a melting pot and meeting ground for different elements, some of which originated in situ and others that colonized the region from adjacent or distant areas at different times (Quézel 1995). During the Quaternary (dating from about 2.5 Myr to th
Data Loading...
