title: Genotyping-by-sequencing approach indicates geographic distance as the main factor affecting genetic structure and gene flow in Brazilian populations of Grapholita molesta (Lepidoptera, Tortricidae).
abstract: The oriental fruit moth Grapholita molesta is one of the major pests of stone and pome fruit species in Brazil. Here, we applied 1226 SNPs obtained by genotyping-by-sequencing to test whether host species associations or other factors such as geographic distance structured populations of this pest. Populations from the main areas of occurrence of G. molesta were sampled principally from peach and apple orchards. Three main clusters were recovered by neighbor-joining analysis, all defined by geographic proximity between sampling localities. Overall genetic structure inferred by a nonhierarchical amova resulted in a significant ΦST value = 0.19109. Here, we demonstrate for the first time that SNPs gathered by genotyping-by-sequencing can be used to infer genetic structure of a pest insect in Brazil; moreover, our results indicate that those markers are very informative even over a restricted geographic scale. We also demonstrate that host plant association has little effect on genetic structure among Brazilian populations of G. molesta; on the other hand, reduced gene flow promoted by geographic isolation has a stronger impact on population differentiation.
authors.affiliation: Laboratório de Melhoramento de Plantas, Centro de Energia Nuclear na Agricultura, Universidade de São Paulo Piracicaba, SP, Brazil.
authors.forename: Karina Lucas
authors.initials: KL
authors.lastname: Silva-Brandão
authors.affiliation: Departamento de Entomologia e Acarologia, Escola Superior de Agricultura 'Luiz de Queiroz', Universidade de São Paulo Piracicaba, SP, Brazil.
authors.forename: Oscar Arnaldo Batista Neto E
authors.initials: OA
authors.lastname: Silva
authors.affiliation: Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas Campinas, SP, Brazil.
authors.forename: Marcelo Mendes
authors.initials: MM
authors.lastname: Brandão
authors.affiliation: Departamento de Entomologia e Acarologia, Escola Superior de Agricultura 'Luiz de Queiroz', Universidade de São Paulo Piracicaba, SP, Brazil.
authors.forename: Celso
authors.initials: C
authors.lastname: Omoto
authors.affiliation: Department of Biological Sciences, CW405 Biological Sciences Centre, University of Alberta Edmonton, AB, Canada.
authors.forename: Felix A H
authors.initials: FA
authors.lastname: Sperling
keywords: genetic structure; host plant association; oriental fruit moth; single-nucleotide polymorphisms