New QTL for resistance to Puccinia polysora Underw in maize.

Southern corn rust (SCR) is a prevalent foliar disease in maize. Deployment of resistant cultivars is an effective way to control SCR. In this study, resistance to SCR was evaluated in a BCRIL population comprising 118 lines grown under three different field conditions. Combined with a genetic map constructed from 1635 SNP markers obtained from the maize 9.4 K SNP Affymetrix® Axiom® Genotyping Array, single quantitative trait loci (QTL) were mapped on chromosomes 4, 9, and 10, respectively. The QTL on chromosome 4 (qSCR4.08) and chromosome 9 (qSCR9.04) were stable across multiple environments, and each explained more than 10% of the phenotypic variation. The stable QTL detected could be desirable sources of SCR resistance in maize-breeding programs.