Format: ORAL

Miguel Serrano1

Department of Botany, Faculty of Pharmacy, University of Santiago de Compostela, Santiago de Compostela, Spain

Jasione is a taxonomically complex genus with a disjunct east-west Mediterranean distribution pattern. Around 16 species are currently recognized, although more than one hundred taxonomic names have been proposed. The hypothesis that intense morphological stasis is concealing evolutionary relevant variability and hampering correct understanding of the evolutionary relationships in the genus needs to be tested. Internal phylogenetic relationships are investigated after a comprehensive sampling including different populations from most of the proposed names, to prevent a priori exclusion of evolutionary significant lineages. The underlying processes leading to the disjunct east-west Mediterranean distribution pattern are discussed. To address these questions, a five cpDNA loci time-calibrated phylogeny was constructed with 111 terminals. The lineage leading to Jasione originated in the late Oligocene (c. 25 Mya) and the extant lineages of Jasione derive from a much later diversification event, occurring in c. 9 Mya in the Miocene, from an ancestor most probably originated in the western Mediterranean region. Two main clades can be identified, one only present in the western Mediterranean and encompassing species with very different morphologies and another with the extant disjunct distribution pattern. The second clade began to diversify at the beginning of the Pleistocene, probably in the Balkan Peninsula, and at least two east to west dispersal events are identified in this clade, with niche modelling identifying niche conservatism in the eastern group and niche expansion in the western group. The disjunct pattern results from a dynamic biogeographic process in which the two extant areas provided the opportunity both to remain and to disperse, increasing the chances of the lineage to endure. Morphological stasis in Jasione led to taxonomic deflation and integrative approaches are addressed. Internal coherence and discontinuities are tested integrating information from key traits, ploidy, ecological niche and adequacy to biogeographical units to support cryptic species hypotheses.