Whole genome comparisons reveal panmixia among fall armyworm (Spodoptera frugiperda) from diverse locations

Authors: SCHLUM, KATRINA - University Of Tennessee; LAMOUR, K - University Of Tennessee; DE BORTOLI, CAROLINE - University Of Tennessee; BANERJEE, RAHUL - University Of Tennessee; EMRICH, SCOTT - University Of Tennessee; Meagher, Robert - Rob; PEREIRA, ELISEU - Universidade Federal De Vicosa; MURUA, MARIA - Estacion Experimental Agroindustrial Obispo Colombres (EEAOC); SWORD, GREGORY - Texas A&M University; TESSNOW, ASHLEY - Texas A&M University; DILLON, DIEGO - University Of Puerto Rico; LINARES PEREZ, ANGELA - University Of Puerto Rico; AKUTSE, KOMIVI - African Insect Science For Food And Health (ICIPE); Schmidt, Rebecca; FANGNENG, HUANG - Louisiana State University; JURAT-FUENTES, JUAN - University Of Tennessee

Submitted to: BMC Genomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/26/2021
Publication Date: 3/12/2021
Citation: Schlum, K., Lamour, K., De Bortoli, C.P., Banerjee, R., Emrich, S.J., Meagher Jr, R.L., Pereira, E., Murua, M.G., Sword, G.A., Tessnow, A.E., Dillon, D.V., Linares Perez, A.M., Akutse, K.S., Schmidt, R.A., Fangneng, H., Jurat-Fuentes, J.L. 2021. Whole genome comparisons reveal panmixia among fall armyworm (Spodoptera frugiperda) from diverse locations. BMC Genomics. 22. Article 179. https://doi.org/10.1186/s12864-021-07492-7.
DOI: https://doi.org/10.1186/s12864-021-07492-7

Interpretive Summary: The fall armyworm is an agricultural pest with long-distance migratory behavior that is threatening food security worldwide. This pest has a host range of more than 80 plant species but is primarily divided into two strain types based on their association and feeding preference on corn (C-strain) or on rice and smaller grasses (R-strain). Researchers from the University of Tennessee, Universidade Federal de Viçosa (Brazil), Estación Experimental Agroindustrial Obispo Colombre (Argentina), Texas A&M University, ICIPE (Kenya), NC State Univ., and LSU, in collaboration with a scientists from USDA-ARS, Center for Medical, Agricultural and Veterinary Entomology, Gainesville, Florida and Temperate Fruit & Vegetable Research Unit, Wapato, Washington, collected samples of fall armyworm from locations in the USA, Argentina, Brazil, Kenya, and Puerto Rico to compare genetic diversity among and within populations. Members from the Eastern Hemisphere were found interspersed within both continental USA overwintering subpopulations from Florida and Texas, suggesting multiple individuals were likely introduced into Africa. Comparisons between laboratory-reared and field collected fall armyworm support similar genomic diversity, validating the experimental use of laboratory strains as archetypes for population studies

Technical Abstract: The fall armyworm (Spodoptera frugiperda, J.E. Smith) is a highly polyphagous agricultural pest with long-distance migratory behavior threatening food security worldwide. This pest has a host range of >80 plant species, but two host strains are recognized based on their association with corn (C-strain) or rice and smaller grasses (R-strain). In this study, the population structure and genetic diversity in 55 S. frugiperda samples from Argentina, Brazil, Kenya, Puerto Rico and the United States (USA) were surveyed to further our understanding of whole genome nuclear diversity. Comparisons at the genomic level suggest lack of clear population structure, other than a minor reduction in gene flow between the two overwintering populations in the continental USA that also corresponded to genetically distinct host strains. Two maternal lines were detected from analysis of mitochondrial genomes. We found members from the Eastern Hemisphere interspersed within both continental USA overwintering subpopulations, suggesting multiple individuals were likely introduced to Africa. Comparisons between laboratory-reared and field collected S. frugiperda support similar genomic diversity, validating the experimental use of laboratory strains. Our research is the largest diverse collection of United States S. frugiperda whole genome sequences characterized to date, covering eight continental states and a USA territory (Puerto Rico). The genomic resources presented provide foundational information to understand gene flow at the whole genome level between S. frugiperda populations.