Abstract:

Head smut of maize (Zea mays L.) caused by Sporisorium reliana is an important fungal disease in China. Development of varieties resistant to this disease is one of the effective approaches to control the disease. In this study, we mapped and characterized quantitative trait Loci (QTL) conferring resistance to head smut. A genetic linkage map with 84 SSR and 48 AFLP marker loci were constructed based on a maize (Zea mays L.) population consisting of 191 F₂ individuals from the cross Mo17×Huangzao4. The linkage map spans maize genome 1 542.9 cM with average interval of 11.7 cM between adjacent markers. The corresponding 184 F₃ families (7 missed) were evaluated for head smut resistance with two replications in Gongzhuling, Jilin province and Harbin, Heilongjiang province under artificial inoculation with chlamydospore, respectively. Quantitative trait Loci (QTL) were detected using composite interval mapping. In Gongzhuling, 5 putative QTL conferring resistance to head smut were detected on chromosomes 1, 2, 3, 8 and 9, respectively, accounting for 10.0% to 16.3% of the phenotypic variance. In Harbin, 5 putative QTL for resistance to head smut were found on chromosomes 1, 2, 3, 4 and 7, respectively, accounting for 4.6% to 13.4% of the phenotypic variance. The QTL with high LR values could be consistently identified on chromosomes 2 and 3 over two environments, displaying over-dominant and additive effects, respectively. These results provided important information for germplasm improvement of heat smut resistance in maize.

Key words: Zea mays L., Head smut, Resistance inheritance, Quantitative trait loci, Molecular marker