DEVELOPING HOST PLANT RESISTANCE FOR THRIPS IN COTTON TO ADDRESS EMERGING INSECTICIDE RESISTANCE

Thrips are major pests of cotton in the U.S. and the main pest species has developed resistance to insecticide seed treatments. Because supplemental applications of insecticide in addition to seed treatments are sometimes required, alternative management tactics are needed to address this unsustainable path which will likely lead to an increased environmental impact and reduced economic viability of cotton production. This project will examine host plant resistance to manage thrips in genotypes from the landrace collection maintained by the US National Plant Germplasm system. These landraces are known to have a broader genetic diversity compared to current commercial varieties. Field trials will be conducted in North and South Carolina to quantify resistance among landraces. Greenhouse and laboratory studies will then explore mechanisms of resistance. Susceptiblity among genotypes will be associated with physical and chemical measurements, including from metabolomic analyses, which involves the identification and quantitation of small molecule metabolites (metabolome) present in any biological system. Our study will be the first, to our knowledge, to use metabolomics as an approach to help identify mechanisms of resistance in cotton, with an ultimate goal of developing tools for cotton breeding programs to help identify resistant genotypes. The USDA ARS PI has rich experience in cotton improvement, and is well prepared and equipped to be an early adopter and user of host plant resistance information resulting from this project. His continued release to industry of high quality cotton germplasm provides an ideal vehicle to transfer germplasm with resistance to thrips to industry breeding programs, with potential to become rapidly adopted by growers as commercial varieties.