A genome-wide association study investigating fumonisin contamination in a panel of tropical maize elite lines

Native genetic resistance is an effective and environmental-friendly alternative to control fungal infections and reduce fumonisin content in maize kernels. Marker-assisted selection can accelerate the genetic gains over breeding cycles. This study aimed to identify genomic regions and candidate genes associated to fumonisin contamination in a panel of tropical maize elite lines. A total of 205 inbred lines were grown under field conditions in Brazil to measure the fumonisin content in grains. The lines were genotyped by sequencing, generating 385,654 high-quality polymorphic single-nucleotide polymorphisms (SNPs). The Genome Wide Association Study (GWAS) identified 40 SNPs located on 19 genomic regions associated to the fumonisin contamination, of which seven were coincident with other studies. Six candidate genes localized within these QTL regions shared functions related with pathogen resistance, six shared functions related with pathogen resistance, including one associated with Fusarium ear rot also identified at bin 10.03 in a previous study. Tropical maize lines resistant to fumonisin contamination were at low frequency in the Embrapa's panel, but most of the resistant lines shared more than 73% of the resistance alleles at SNP loci associated with the trait. Thus, favorable alleles could be potentially used to improve resistance to fumonisin contamination in maize.