A Genome-Wide Association Study for Fumonisin Contamination Resistance in Tropical Maize

Abstract

Native genetic resistance has been considered an effective and environmentally safe alternative to control fungal infections and to reduce mycotoxins accumulation in maize grains. Marker-assisted breeding can be used to accelerate the genetic gains for fumonisin contamination resistance. Thus, the objective of this study was to identify quantitative trait loci (QTLs) and candidate genes for resistance to fumonisin contamination in an Embrapa’s tropical maize panel. Two-hundred and five inbreed lines were evaluated in three field trials Brazil in order to quantify fumonisin contamination in maize grains. The lines were genotyped-by-sequencing (GBS), generating 385,654 high-quality polymorphic SNPs. Mycotoxins in the grain samples were isolated using commercial immunoaffinity columns and its concentrations were evaluated by fluorometric technique. Nine quantitative trait loci (QTL) were found associated with fumonisin concentration resistance in maize. Seven candidate genes with annotated functions associated with biosynthetic pathways of pathogen resistance and four genes have not been previously described as related to fumonisins contamination resistance. These findings will be important to better understand the fumonisin contamination resistance and to support the development of SNP markers to accelerate the selection process in tropical maize breeding programs.