DECIPHERING THE GENETIC BASIS OF S. CHACOENSE MEDIATED COLORADO POTATO BEETLE RESISTANCE

The Colorado potato beetle (Leptinotarsa decemlineata) (CPB) is the most widespread anddestructive insect defoliator pest of potato and its control has historically been achieved throughthe use of insecticide. The diploid potato species S. chacoense has been utilized for over 4 decadesin an attempt to introgress glycoalkaloid-based insect resistance into cultivated potato. Despitethese efforts, insect resistant cultivars have not been achieved, due in part to polyploidy,heterozygosity, and the complex genetics underlying the trait. We propose that the introgressionof self-compatibility into diploid insect resistant S. chacoense germplasm will provide an idealgenetically structured germplasm and set of populations that will allow us to study, understand anddeploy this mechanism of host-plant insect resistance in cultivated, diploid breeding lines.Integrating expression and metabolite profiling with genomic variants identified between highlyhomozygous, diploid CPB resistant and susceptible S. chacoense genomes, we will curate highconfidence genes conferring CPB resistance. We will utilize genome editing technology to validatethe necessity and sufficiency of candidate genes. This information will facilitate the developmentof markers to efficiently transfer beetle resistance identified in wild relatives to cultivated material.