Format: ORAL

Carlos Vila-Viosa1,2,3,4,*, RicardoArraiano-Castilho5, AndrewHipp6, FranciscoM.Vzquez7, Rubim Almeida1,2,3,4, Cristina Garca8, Albano Beja-Pereira1,2,9, Herlander Azevedo1,2,4

1 BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO. Campus de Vairão, 4485-661 Vairão, Portugal 2 CIBIO (Research Center in Biodiversity and Genetic Resources) - InBIO (Research Network in Biodiversity and Evolutionary Biology), University of Porto. Campus Agrário de Vairão; Rua Padre Armando Quintas; 4485-661 Vairão; Portugal 3 MHNC-UP - Museu de História Natural e da Ciência da Universidade do Porto – Herbário PO, Universidade do Porto. Praça Gomes Teixeira, 4099-002, Porto, Portugal 4 Departamento de Biologia, Faculdade de Ciências, Universidade do Porto. Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal 5 Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland 6 The Morton Arboretum, Lisle IL 60532-1293, USA 7 Department of Forest Production and Vegetal Biodiversity, Institute of Agricultural Research “Finca La Orden Valdesequera” (CICYTEX), A5 km 372, 06187 Guadajira, Spain 8 Department of Biological Science. Centre for Evolution, Ecology and Behaviour. Bourne Building, Office 3-29B. Royal Holloway University of London, Egham, Surrey, TW20 EX, United Kingdom 9 DGAOT, Faculdade de Ciências, Universidade do Porto, Rua Campo Alegre 687, 4169-007 Porto, Portugal

The Iberian Peninsula is a wide known hotspot and refugia for the Eurasian white oak species. In classic literature, this group of oaks are traditionally assumed to form common hybrid swarms, and their resulting nothotaxa have suffered of nomenclatural uncertainty. This comes from natural history artifacts and the unknown validation of putative parent species, as valid taxa that have been suffering of distinct rankings, with no consensus by the broad authors that treated the Iberian oaks. Here, we aimed to ?re-assess the phylogeographic relationships among species and investigate the occurrence of hybrid swarms in marcescent oak species (Subsection Macrantherae) across the Iberian Peninsula, disentangling putative hybridization and ancestral relationships. Towards this end, we used restriction-site associated DNA sequencing (RADSeq) to identify single nucleotide polymorphisms across the genomes of 275 samples representing eight widespread Iberian oak species, including infraspecific taxa and nothotaxa. Our results show that the marcescent oak species addressed in this study hold high levels of hybridization, validating several nothotaxa (Q.coutinhoi, Q. cerrioides, Q. subpyrenaica, Q. tlemcenensis) known to form hybrid swarms in particular biogeographic areas of the Iberian Peninsula, where sometimes they exclude at least one of the parental species. We discuss these results in the framework of the Iberian oak forests conservation, and the implications it brings to understanding the western Mediterranean biogeography. Finally, we conclude that binding taxonomic and biogeographic awareness, rooted in strong historical collections and literature review is of extreme relevance for solving difficult groups of plants displaying reticulate evolution.