Year: 2020
Type: preprint
Abstract: A successful biological invasion involves survival in a newly occupied environment. If a population bottleneck occurs during an invasion, the resulting depletion of genetic variants could increase inbreeding depression and decreased adaptive potential, potentially resulting in the extinction. How invasive populations survive and thrive in a newly occupied environment and how, in many cases, they maintain moderate levels of heterozygosity are still contentious issues. The pest Fall armyworm (FAW; Lepidoptera: Spodoptera frugiperda) is native to the Western hemisphere. Its invasion in the Eastern hemisphere was first reported from West Africa in early 2016, and in less than four years, it swept sub-Saharan Africa and Asia, finally reaching Australia. In this study, we used population genomics approaches to investigate the factors explaining the invasive success of the FAW. We observe a drastic loss of mitochondrial polymorphisms in invasive populations, whereas nuclear heterozygosity exhibits a mild reduction. The population from Benin in West Africa has the lowest length of linkage disequilibrium amongst all invasive and native populations despite its reduced population size. This result supports that balancing selection increased heterozygosity by facilitating the admixture of invasive populations from distinct origins and that, once heterozygosity was sufficiently high, the FAW started spreading globally in the Eastern hemisphere. As comparable heterozygosity levels between invasive and native populations are commonly observed, we postulate that heterozygosity restoration through balancing selection could be widespread among successful cases of biological invasions.
Authors: Sudeeptha Yainna, Wee Tek Tay, Estelle Fiteni, Fabrice Legeai, Anne-Laure Clamens, Sylvie Gimenez, Marie Frayssinet, R Asokan, CM Kalleshwaraswamy, Sharanabasappa Deshmukh, Robert L. Meagher, Carlos A. Blanco, Pierre Silvie, Thierry Brévault, Anicet Dassou, Gael J. Kergoat, Thomas Walsh, Karl Gordon, Nicolas Nègre, Emmanuelle d’Alençon, Kiwoong Nam
Institutions: Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement, Diversité, génomes et interactions micro-organismes-insectes, Commonwealth Scientific and Industrial Research Organisation, Lyon 1 Université, Université de Montpellier, Institut national de recherche en sciences et technologies du numérique, Institut de Recherche en Informatique et Systèmes Aléatoires, Institut de Génétique, Environnement et Protection des Plantes, Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Institut Agro Montpellier, Centre de Biologie pour la Gestion des Populations, Institut de Recherche pour le Développement, Indian Institute of Horticultural Research, University of Agricultural and Horticultural Sciences, Agricultural Research Service, United States Department of Agriculture, Animal and Plant Health Inspection Service, Agro-écologie et intensification durable des cultures annuelles, National University of Sciences, Technologies, Engineering and Mathematics
Language: English
Subfield: Genetics
Domain: Life Sciences
SDGs: Life on land, Zero hunger
Open Access status: green
Funders: Agropolis Fondation, Commonwealth Scientific and Industrial Research Organisation, Agence Nationale de la Recherche, Institut National de la Recherche Agronomique, Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement
OpenAlex ID: W3097270865