Abstract:Southern corn rust has become an economically important disease that affects maize yield in China. To explore new genetic resources for resistance to southern rust, we developed F1 hybrids and F2 population by a cross between a highly resistant inbred line W456 and susceptible Huangzaosi. These genetic materials were subjected for genetic analysis and QTL mapping of resistance genes. A framework of linkage map comprising 200 SSR markers was constructed which expands 3331 cM of the maize genome with an average marker interval of 16.6 cM. QTL mapping for resistance was conducted using software IciMapping V4.1 package for inclusive composite interval mapping. As a result, six QTLs including qSCR3, qSCR7, qSCR8-1, qSCR8-2, qSCR9 and qSCR10, were detected on chromosomes 3, 7, 8, 9 and 10, which were flanked by markers umc2105 and umc1729, umc1066 and bnlg2271, umc1904 and umc1984, umc1984 and bnlg1651, umc1957 and bnlg1401, and umc2034 and umc1291, respectively. The phenotypic variance explained (PVE) ranged from 2.61% to 24.19%, explaining 62.3% of the total phenotypic variation. Notably, qSCR10 on chromosome 10 accounted for 24.19% of the phenotypic variation, thus being a major QTL responsible for resistance to southern rust in maize. Moreover, this resistance locus was further delimited by new flanking markers to a 2.51 cM genetic interval. Thus, this work accomplished the preliminary mapping of resistance loci, which might be valuable in breeding for resistant varieties against Southern corn rust.