ORIGINAL RESEARCH published: 25 August 2021 doi: 10.3389/fpls.2021.687094 Asymmetric Reproductive Barriers and Gene Flow Promote the Rise of a Stable Hybrid Zone in the Mediterranean High Mountain Mohamed Abdelaziz 1*†, A. Jesús Muñoz-Pajares 1,2,3†, Modesto Berbel 1, Ana García-Muñoz 1, José M. Gómez 3,4 and Francisco Perfectti 1,3 1 Departamento de Genética, Facultad de Ciencias, Campus Fuentenueva, Universidad de Granada, Granada, Spain, 2 Laboratório Associado, Plant Biology, Research Centre in Biodiversity and Genetic Resources, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade Do Porto, Campus Agrário de Vairão, Fornelo e Vairão, Portugal, 3 Research Unit Modeling Nature, Universidad de Granada, Granada, Spain, 4 Departamento de Ecología Funcional y Evolutiva, Estación Experimental de Zonas Áridas, Consejo Superior de Investigaciones Científicas, Almeria, Spain Edited by: Andrew A. Crowl, Hybrid zones have the potential to shed light on evolutionary processes driving Duke University, United States adaptation and speciation. Secondary contact hybrid zones are particularly powerful Reviewed by: Adrian Christopher Brennan, natural systems for studying the interaction between divergent genomes to understand Durham University, United Kingdom the mode and rate at which reproductive isolation accumulates during speciation. We Santiago Martín-Bravo, Universidad Pablo de Olavide, Spain have studied a total of 720 plants belonging to five populations from two Erysimum *Correspondence: (Brassicaceae) species presenting a contact zone in the Sierra Nevada mountains Mohamed Abdelaziz (SE Spain). The plants were phenotyped in 2007 and 2017, and most of them were
[email protected] genotyped the first year using 10 microsatellite markers. Plants coming from natural †These authors have contributed populations were grown in a common garden to evaluate the reproductive barriers equally to this work and share first between both species by means of controlled crosses.