Validation of two QTL Associated with Sclerotinia Blight Resistance in Peanut

Sclerotinia blight, caused by Sclerotinia minor Jagger, is a fungal disease of peanut that is widespread throughout the cooler peanut-growing regions of theU.S. and can cause yield losses up to 50%, threatening sustainable peanut production. Few cultivars with acceptable resistance have been developed due toa limited understanding of the inheritance of the trait. In this study, correlation of genotypic data collected from a RIL mapping population (Tamrun OL02 x PI497429), and phenotypic data collected between 2017 and 2020 revealed two QTL potentially associated with Sclerotinia blight resistance. Subsequently, members from a validation RIL population (Okrun X PI 497429) were selected based on genotype and phenotyped in 2023 for resistance under heavy disease pressure. Correlation of phenotypic and genotypic data validated the two QTL associated with resistance to Sclerotinia blight on chromosomes 6 and 15. These results will be used to develop and deploy markers for screening breeding populations and germplasm collections, as well as aid in the selection of advanced breeding lines for development of Sclerotinia-resistant cultivars.