QTL Mapping for Fusarium Ear Rot and Fumonisin Contamination Resistance in Two Maize Populations

Fusarium verticillioides (Sacc.) Nirenberg (synonym F. moniliforme Sheldon) (teleomorph: Gibberella moniliformis) and F. proliferatum (Matsushima) Nirenberg (teleomorph: G. intermedia) are fungal pathogens of maize (Zea mays L.) that cause ear rot and contaminate grain with fumonisins, mycotoxins that can harm animals and humans. The objective of this study was to identify quantitative trait loci (QTL) for resistance to Fusarium ear rot and fumonisin contaminationintwomaizepopulations,comprisedof213BC1F1:2familiesfrom the first backcross of GE440 to FR1064 (GEFR) and 143 recombinant inbred lines from the cross of NC300 to B104 (NCB). QTL mapping was used to study the genetic relationships between resistances to ear rot and fumonisin contamination and to investigate consistency of QTL acrosspopulations.IntheGEFRpopulation,sevenQTLexplained47% of the phenotypic variation for mean ear rot resistance and nine QTL with one epistatic interaction explained 67% of the variation for mean fumonisin concentration. In the NCB population, five QTL explained 31% of the phenotypic variation for mean ear rot resistance and six QTL and three epistatic interactions explained 81% of the phenotypic variation for mean fumonisin concentration. Eight QTL in the GEFR population and five QTL in the NCB population affected both disease traits. At least three ear rot and two fumonisin contamination resistance QTL mapped to similar positions in the two populations. Two QTL,localized tochromosomes fourand five, appearedtobe consistent for both traits across both populations.