|COAN, MARLON - Universidade Estadual De Maringá
|SENHORINHO, HENRIQUE - Universidade Estadual De Maringá
|SCAPIM, CARLOS - Universidade Estadual De Maringá
|PINTO, RONALD - Universidade Estadual De Maringá
|TESSMANN, DAURI - Universidade Estadual De Maringá
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/1/2017
Publication Date: 2/1/2018
Citation: Coan, M., Senhorinho, H., Scapim, C., Pinto, R., Tessmann, D., Williams, W.P., Warburton, M.L. 2018. Genome-wide association study of resistance to ear rot by Fusarium verticillioides in a tropical field maize and popcorn core collection. Crop Science. 58:564-578. https://doi.org/10.2135/cropsci2017.05.0322.
Interpretive Summary: Corn is a valuable commodity used for industrial purposes, as a feed grain, and as a food staple around the world. Brazil is the third largest producer of corn, but yield is threatened by several diseases in the tropical growing environments. Fusarium ear rot (caused by Fusarium verticillioides) is one of the more destructive diseases of corn in Brazil. The development of corn lines that are resistant to infection by the fungus would alleviate the problem in an efficient and very economical manner for farmers. In this study, we have applied genome wide association mapping to identify genes with a very high probability of causing resistance to fusarium ear rot. Four genes in regions of the chromosomes with high probability encode defense related proteins and can soon be used to breed new resistant maize lines and hybrids in the most efficient manner possible.
Technical Abstract: Fusarium ear rot (caused by Fusarium verticillioides) is one of the most prevalent diseases of maize worldwide, and has one of the greatest negative economic impacts on this cereal crop globally. Fusarium ear rot is a highly complex trait, under polygenic control with minor effects per gene and low heritability, and is strongly influenced by environmental conditions. The aim of this study was to identify genomic regions, including putative candidate genes, associated with resistance to fusarium ear rot and the starburst pattern caused by F. verticillioides under artificial inoculation. We conducted a genome-wide association study using high-quality single nucleotide polymorphism (SNP) markers (268k) with phenotypic data from three environments on a panel of 183 inbred linesand a set of 267,525 polymorphic SNPs generated using genotyping by sequencing. Fourteen SNPs were significantly associated with fusarium ear rot, some of which were co-localized to previously reported QTL regions, and some of which were novel. Four genes linked to the associated SNPs encode defense related proteins including gibberellin 2-oxidase4, a glucosyltransferase, a Ras-related protein RHN1 and phosphoribosylanthranilate transferase. Each of these SNPs explains a considerable proportion of the phenotypic variance, ranging from 15% to 25%. Once these SNPs are validated, they will be useful for marker–assisted selection and for a better understanding of maize resistance to Fusarium ear rots.