QTL mapping of resistance to Sporisorium reiliana in maize

We mapped and characterized quantitative trait loci (QTL) for resistance to Sporisorium reiliana. A population of 220 F-3 families produced from the c ross of two European elite inbreds (D32, D145) was evaluated with two repli cations at a French location with high natural incidence of S. reiliana and at a Chinese location employing artificial inoculation. The 220 F-3 famili es were genotyped with 87 RFLP and seven SSR markers. Using composite inter val mapping, we identified two different sets of 3 and 8 QTL for the French and the Chinese locations explaining 13% and 44% of respectively. Individu al QTL explained up to 14% of <(sigma)over cap>(2)(p). The 11 QTL mapped to eight maize chromosomes and displayed mostly additive or partial dominant gene action. Significant digenic epistatic interactions were detected for o ne pair of these QTL. Only a few QTL for S. reiliana were in common with QT L for resistance to Ustilago maydis and Puccinia sorghi, identified at a Ge rman location for the same population. Consequently, in our materials resis tance to these three fungal pathogens of maize seems to be inherited indepe ndently.