Prospecting molecular markers for evaluating the risk of evolution of pest resistance to insecticides and genetically modified plants in agricultural systems

Abstract

The adoption of biotechnology for managing insect pests has been increasing in Brazil, especially in genetically modified crops such as soybean, corn and cotton that express Bacillus thuringiensis (Bt) proteins. One of the major threats to preserve the lifetime of these technologies as well as insecticides used in agricultural systems has been the evolution of resistance of target pests to insecticides and Bt crops. Therefore, this research aims to identify molecular markers for resistance monitoring to be used in a proactive resistance management programs. Initially, we will conduct phenotypic monitoring of the susceptibility to flubendiamide (a diamide insecticide widely used in the management of these species) and to Cry1Ac protein expressed in Bt soybean in populations of Chrysodeixis includens and Helicoverpa armigera collected from different regions of the country in 2020 and 2021 growing seasons, besides the estimation of the frequency of the alleles that confer resistance and characterization of the inheritance pattern and the fitness cost of resistance to Cry1Ac. Then, screening of the SNPs under selection pressure of these populations will be carried out to identify the molecular markers and mapping of molecular markers using QTL and GWAS in field populations and F2 biparental population of H. armigera resistant to flubendiamide. These studies are essential for establishing the basis of a resistance management program of C. includens and H. armigera to flubendiamide and to the insecticidal protein Cry1Ac expressed in soybean and cotton biotechnology events, as well as to support the management strategies of Integrated Pest Management (IPM) for these two important pests in agricultural agrosystems in Brazil. (AU)