Inheritance of multiple resistance to fungal diseases in tropical maize germplasm

Abstract

Maize (Zea mays L.) ear rots caused by Aspergillus flavus, Fusarium graminearum and Stenocarpella maydis affect grain quality and are associated with mycotoxins that pose precarious food and feed safety issues. The objective of this study was to determine the inheritance of multiple resistance to major fungal pathogens (Aspergillus flavus, Fusarium graminearum and Stenocarpella maydis) in maize in the tropical Africa. A total of 30 tropical inbred lines with varying resistance to A. flavus and both F. graminearum and S. maydis, were mated in a North Carolina II Design and the progeny consisting of single crosses, test crosses and their parents evaluated for single infection and yield performance. Resistance to the three ear rot pathogens and grain yield was found to be inherited independently. Therefore the three fungal infections had low or negligible effect on grain yield, though adversely reduced the grain quality. Multiple resistance to the three ear rot pathogens was majorly additive in nature. Some non-additive gene effects like dominance and epistasis could be contributing to multiple ear rot resistance. Maize hybrid vigour was found to enhance ear rot resistance.