Format: ORAL

Jacopo Franzoni1, Gianluigi Bacchetta2, Fabio Conti3, Gianniantonio Domina4, Simone Fior5, Luigi Minuto6,Lorenzo Peruzzi1

1 University of Pisa, Pisa, Italy 2 University of Cagliari, Cagliari, Italy 3 University of Camerino, Camerino, Italy 4 University of Palermo, Palermo, Italy 5 ETH Zürich, Zürich, Switzerland 6 University of Genova, Genova, Italy

Species are hypotheses about how biological diversity is structured in nature, and robust hypotheses are typically supported by multiple lines of evidence. However, traditionally botanists have been prone to circumscribe species relying just on morphological observations. For instance, the Dianthus virgineuscomplex includes 21 wild putative species/subspecies in the central Mediterranean recognized according to qualitative morphology, but their boundaries await to be explored with other approaches. Thus, we are conducting an integrative taxonomy project to test the current taxonomy of the complex. For this purpose, we collected morphometric, cytogenetic, and genomic (ddRAD-seq) data from over 100 populations belonging to all the 21 taxa. The global structure of the morphometric dataset, built using continuous and categorical variables, suggest the presence of just two main groups. Populations distributed from southern France to peninsular Italy show shorter calyx teeth, epicalyx scales and mucros with respect to populations from Sicily and Corso-Sardinian system (including Tuscan Archipelago). These two groups show sub-clusters, only in some cases mirroring currently accepted taxa. These plants are all diploid with constant chromosome number (2n = 2x =30), albeit relative genome size is slightly higher in populations from Sicily and from Corso-Sardinian system. Genotyping thousands of SNPs revealed a genetic structure that parallels geography rather than taxonomy. Studied populations from the central Mediterranean belong to a unique genetic lineage, structured in two major clines. A first cline extends from southern France to the southern part of the Italian Peninsula, and the other from the Italian Peninsula to the Tuscan Archipelago, Corsica, and Sardinia. Sicilian and Sardinian populations are linked through those originating from Tunisia. All these evidences point to a number of groups lower than currently recognized taxa. In-depth morphometric classification models and multispecies coalescence model-based approaches are currently ongoing to test current and alternativetaxonomical settings.