BREEDING FOR RESISTANCE TO FALLARMYWORM (Spodoptera frugiperda J.E. Smith) IN MAIZE

Abstract

Incursion of the fall armyworm (FAW) in Africa and some other part of the world since 2016 has posed serious threat to food security. Conventional breeding has been extensively used to develop resistant genotypes through artificial and natural screening. Studies have been carried out on diet combinations for mass rearing of the insect for effective screening. However, due to the length of time involved and problem of genotype by environment, a faster approach through use of transgenes have been employed. In the Americas, Bt maize has successfully controlled FAW, however it has been discovered that the FAW is resistant to some of these Bt genes. Bt maize has also been released in Nigeria and few other parts of Africa. Molecular markers have also been used to fast-track progress in breeding for resistance to FAW. Simple Sequence Repeat (SSR) and Single Nucleotide Polymorphism (SNP) markers have been used to determine FAW identity, validate the origin of the African FAW population, and identify the main QTL for FAW resistance in maize. One of the most sophisticated methods for mapping the regions of the genome is the use of Genome-Wide Association Studies (GWAS), which is currently being used to investigate loci associated with resistance against FAW among maize genotypes. Some FAW resistant maize genotypes have been released for commercialization and some are still in the pipeline.