Molecular Markers for Assisted Selection in Sclerotinia Blight and Peanut Smut Resistance

Argentina is a global leader in peanut production, exporting over 90% of its yield to nearly 100 countries. However, soilborne diseases, particularly Sclerotinia blight and peanut smut, critically impact the sustainability of peanut agriculture. Sclerotinia blight, caused by Sclerotinia minor and S. sclerotiorum , and peanut smut, caused by Thecaphora frezzii, have led to severe economic losses with incidence rates up to 50%. Despite efforts in cultural and chemical disease management, their effectiveness is limited. Consequently, the development of resistant cultivars offers a realistic and sustainable solution. This study focuses on developing and validating KASP markers for resistance against these diseases. By adapting a rapid and cost-effective DNA extraction method, the research facilitated the genotyping of 2,575 F2 plants derived from five crosses of promising parental lines. Three KASP markers for each disease were tested, with Scl1, Scl3, and S3 showing high predictive efficiency for Sclerotinia blight and peanut smut. The study identified 265 plants carrying resistance alleles which represents 10.3% of the total tested plants. These findings highlight the potential of molecular markers in breeding disease-resistant peanut varieties, ensuring sustainable production in Argentina.