Identification of QTL for resistance to head smut in maize (Zea mays. L)

Abstract

Head smut (HS) is one of the most devastating diseases of maize in spring production regions in China. Quantitative trait loci (QTL) for HS resistance were identified in this study to provide theoretical and applied tools for breeding HS resistance in maize. QTL associated with HS resistance were identified in a F_2:3 population derived from a T32 (highly resistant genotype) × HC (highly susceptible genotype) cross. Analysis in each of three environments and a collective analysis across all three environments were used to identify QTL in the F_2:3 population. A significant difference in HS resistance was found between the inbred lines, ‘T32’ and ‘HC’. Large genetic variation and transgressive segregation in the F_2:3 population were observed between the three different sites, Guian (GA), Huaxi (HX), and Pingba (PB). Two stable and novel QTL for resistance to HS were detected in the different environments that were located within the bnlg1014 to umc2224 (qHS1) interval on chromosome 1 and in the umc1006 to umc1857 (qHS6) interval on chromosome 6. Both QTL can be used for further fine mapping, marker-assisted selection breeding, and theoretical studies on HS resistance in maize.