Resistance to insecticide in Euchistus heros (Hemiptera: Pentatomidae): genetic diversity and association mapping of resistance genes

Abstract

The popularization of Bt soybeans strains- primarily used to control lepidopterans larvae -, the environmental changes caused by the expansion of cropping areas, and climate changes will change the status of E. heros and other pests from secondary pests to primary pest and eventually will become the primary focus of the pest management in soybean crops. For the efficient management of E. hero's population levels, chemical control using insecticides is widely used and possible complications derived from its usage must be addressed. Problems such as the rapid evolution of resistance to insecticide molecules, the range expansion of the pest to other areas, the dispersion of resistance gene might make E. heros a real concern to Brazilian agribusiness. Next Generation Sequencing (NGS) applied to population genomics is nowadays an important tool for the characterization of genetic diversity helping us to understand gene flow pattern in a landscape. The selection of environmental and climatic variables can shed light on the phenomenon of local adaptation. Popular approaches using quantitative tools such as association mapping can link phenotypes such as insecticide resistance to specific markers are now feasible and considerably simpler. Genotyping by Sequencing (GBS) has become very popular in recent years and has helped to elucidate important problems in many different research fields. The objectives of this project are to monitoring insecticide resistance in Brazilian populations, to characterize the genetic diversity in the main soybean producing regions in Brazil, to identify markers associated with different levels of resistance to insecticides, to identity of possible markers under selection, and to generate predictive models for the gene flow. The changes in allelic frequencies in soybean regions, the information regarding where are the major focuses of allelic diversity, the discovery of major gene flow routes, and identification of local adaptation will provide valuable information for decision-makers to define better tactics and management plans for E. heros.