Identification of QTL’s Linked for Resistance to Maize Cob Rot Caused by Fusarium graminearum in Tropical Maize

Maize cob rots caused by Fusarium graminearum cause yield losses and quality as a result of produced mycotoxins. Developing varieties resistant to cob rots is an alternative strategy that is practical and provides better insurance for the small scale farmers. The subjectivity of scoring and the varying virulence responses of these pathogens to environmental conditions make selection for resistance difficult. The objectives of this study were to i) identify quantitative trait loci (QTL’s) associated with resistance to F. graminearum and ii) evaluate the possibilities of utilising these QTL’s for marker assisted selection (MAS). A major QTL was identified on chromosome 5. The additive and dominance effects ranged from -0.11 to - 0.30 and all detected QTL’s were more than 5 cM from the nearest molecular marker utilised in the study. Therefore, there is need to utilise the maize genomic map to identify and test several markers (< 5 cM, to the detected QTL’s), in order to locate more reliable molecular markers for utilization in MAS.