Phylogeography and evolution of three ecologically divergent amphi-Adriatic plant groups

 Funding: Croatian Science Fund (HRZZ): Installation Research Grants (UIP-05-2017)

 Project duration: 01. 03. 2018. – 28. 02. 2023. (60 months)
 Project leader: Ivana Rešetnik, PhD
 Project number:  UIP-2017-05-2882
 Funding (HRZZ): 1.516.075,00 HRK (202.143,00 EUR)
 Co-funding (PMF): 227.900,00 HRK (30.387,00 EUR)

Project summary:
South-eastern Europe is one of the major European biodiversity hotspots largely due to the fact that Apennine and Balkan Peninsulas have acted as major glacial refugia for temperate plant and animal species during the glacial–interglacial cycles of the Quaternary. The impact of Pleistocene climatic fluctuations in shaping intraspecific genetic variability of the Peninsulas is still not well understood, although several microrefugia have been proposed for some plant groups on the Balkans (‘refugia-within-refugia hypothesis’). Here we propose a comparative phylogeographic study that combines traditional (morphology and plastid DNA sequences) and state-of-the–art approaches taking advantage of the next-generation sequencing (Restriction-site associated DNA sequencing, RADseq) and ecological niche modelling in order to uncover mechanisms that contributed to the high levels of south European biodiversity. Specifically, we aim to explore the evolutionary trajectories and diversification of three ecologically divergent plant groups distributed on both sides of the Adriatic (amphi-Adriatic) and thus across the two southern European glacial refugia, Apennine and Balkan Peninsulas. The project contains four inter-related components. First, we aim to reconstruct the individual phylogeographic histories of Aurinia leucadea, A. sinuata, Dianthus sylvestris group and Festuca bosniaca on the two Peninsulas in order to assess evolutionary pathways and reveal range-wide patterns of genetic diversity of divergent lineages. In addition, we will explore whether ecologically divergent plant groups responded differently to Pleistocene climatic fluctuations. Second, we aim to identify morphological variation of the study groups and examine if the morphological divergence corresponds to their genetic diversity and/or current taxonomy. Third, we will evaluate ecological niches of the study groups to obtain their potential present and past habitat suitability pointing to putative refugial locations, and to examine the relationship between their genetic and environmental divergences. Fourth, we will examine spatial and temporal congruence among the reconstructed phylogeographies and compare inferred locations of glacial refugia and postglacial expansion routes. In particular, we ask whether the Apennines harbour similar microrefugia as detected in the western Balkans and Iberian Peninsula and whether genetic structure and migration routes across the Adriatic differs between ecologically contrasting study groups. The strength of the proposed study lies in the following: 1) the implementation of high-resolution RADseq data will provide comprehensive examination of natural variation within range-wide native environment, 2) the obtained results will present direct contribution to conservation and management of the endemic and threatened species 3) the synthesis of comparative phylogeography and ecological niche modelling will yield a much broader basis to address questions of interest going beyond investigated groups: how the biodiversity on the Balkans and Apennines arose and which processes were involved in its formation. Therefore, our integrated approach tackles the central issues in evolution and conservation biology and based on our results we expect to outline further prospects for research of south-eastern European diversity.