CONICET | Buscador de Institutos y Recursos Humanos

Genetic studies in Lepidoptera allow the identification of adaptive genes under selection associated with ecological phenotypes. Diatraea saccharalis (Lep. Crambidae) has a wide geographical distribution and wide range of host plants. However, genetic and reproductive studies suggest the existence of biotypes by geographic isolation and an insect-host association. The aim of this study was to explore the genetic variability of D. saccharalis populations through a mitochondrial marker COI and a nuclear marker (genomic library). The populations were collected on sugarcane and conventional corn, in Tucumán, Jujuy, Buenos Aires and San Luis provinces of Argentina. On the other hand, to obtain a regional perspective, populations of Brazil from sugarcane and conventional corn were included in the genomic library study. The COI marker showed significant differences in the Fu?s F test that revealed incipient expansion processes in the populations. The analysis of the minimum extension network resulted in 17 haplotypes with a distribution that shows changes in the genetic diversity of the populations. From the genomic library, 2349 outlier loci were determined, which indicate that environmental factors are potentially responsible for adaptive divergence. The inbreeding coefficient (Fis) shows that the mating, although it is random, presents a certain degree of selection. The values of FST (statistical index of fixation) showed a high variation among the populations of Argentina and Brazil. The Discriminant Analysis of Principal Components, based on geographic variation and host plants, showed three groups, revealing changes in the genetic structure of the populations by subdivision. The divergence obtained is predicted within the divergence model with partial gene flow, influenced in different degrees by the action of factors such as geographical isolation, insect-host plant association and different founding events.