Format: ORAL

Modesto Berbel1, Ana Garca-Muoz1, Andrs Ferreira-Rodriguez1, Melissa Moniz1, Jos Carlos del Valle2, Eduardo Narbona3, Gonzalo Nieto-Feliner4, A. Jess Muoz-Pajares1, Mohamed Abdelaziz1.

1 Departamento de Genética, Universidad de Granada, Granada, Spain 2 Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Seville, Spain 3 Departamento de Biología Molecular e Ingeniería Bioquímica, Universidad Pablo de Olavide, Seville, Spain 4 Departamento de Biodiversidad y Conservación, Real Jardín Botánico (RJB), CSIC, Madrid, Spain

The species hybridization is a phenomenon which consequences can go from the collapse and loss of diversity to the rise of this diversity. Global change, are promoting the secondary contact and hybridization between diverging taxa with incomplete reproductive barriers. These hybrid zones have the potential to shed light on evolutionary processes driving adaptation and are particularly powerful natural systems for studying the interaction between divergent genomes to explore how the rise of phenotypic novelties can modify the evolutionary trajectory. We have studied a total of 480 plants belonging to six populations and two transects of two Erysimum (Brassicaceae) species presenting a contact zone in the Serra da Estrela (Portugal). The plants were phenotyped using 25 traits and genotyped using more than 4000 SNPs across their whole genomes. Plants also were tagged during a complete session of reproduction and we used different component to quantify their fitness. We analyzed the patterns of hybridization using genomic approach, identifying two hybrid zones in different stages of hybridization. When we explore the patterns of natural selection acting on the parental and hybrid plants, we found different traits related to plant size and reproductive investment driving the population evolution for the parental plants. However, the natural selective pressures acting on hybrids were variable depending on the evolutionary stage of the hybrid zone. In the hybrid zone enriched with F1-hybrids we identified new adaptive trajectories acting on traits not selected in parental species. But the hybrid zone enriched by F2 and backcrosses, the adaptive trajectories were similar to those found at parental sites. Our results demonstrate that hybrids promote the rise of novelties in plant evolution but in absence of transgressive phenotypes the hybrid zone tends to become in parental secondary contact zones.