Genetics on Resistance to Maize Kernel Infection by Aspergillus Flavus : Basics, Methodologies, Principles and Strategies

Maize kernel infection by Aspergillus flavus and later aflatoxin contaminatuion are worldwide problems in production and storage. Genetic resistance to A. flavus is most cost-effective to minimize the loss to kernels. To study the inheritance of A. flavus resistance, maize diallel and half-sib family crosses were made and genetic effects analyzed for percent kernel infection (PKI) rates using MIKI. Highly significant GCA, SCA and reciprocal effects were found. Two parents had desirable GCA effects on enhancing the average resistance performance in hybrid progeny. Three crosses had consistently negative SCA effects over year. They revealed that genetic resistance to kernel infection by A. flavus existed in maize and was identifiable and exploitable. Both diallel and half-sib analyses agreed and confirmed genotypic, additive and dominance effects. Lab-based PKI compared with the field-based demonstrated that it was more effective in screening for resistant maize germplasm. This study is instructive to breeders, geneticists, and pathologists in that these methods can be realistic solutions to identifying desired genes and breeding for genetic resistance.