Genomic Analysis of Resistance to Exserohilum turcicum in Nigerien and Senegalese Sorghum Using GWAS and Machine...

Sorghum, an essential crop in Niger, ranks second to pearl millet in importance for food, feed, and commerce. However, its yields are hindered by various factors, including diseases such as leaf blight caused by Exserohilum turcicum. In this study, field phenotypes were analyzed on 102 accessions (including checks SC748-5 and BTx623) grown and evaluated at two locations in Niger for leaf blight incidence and severity. The panel included accessions originally collected from Niger and Senegal. Genotypes were generated for 120 accessions, and GWAS/ML analyses were performed on 102 accessions due to missing phenotypic data. Among the accessions, S39, N23, and N38 exhibited mean leaf blight incidence below 50%, while S3, S43, N23, and N38 displayed the lowest severity levels, with a mean severity in Niger of 24.5 ± 0.64. Accession N23 showed relatively low incidence and severity levels across the Niger field evaluations. Using genome-wide association studies and machine learning, candidate SNPs associated with leaf blight phenotypes were identified. Genes near these SNPs were associated with functions related to plant defense mechanisms and stress responses, providing preliminary targets for future validation in sorghum leaf blight studies.