Location: Plant Science ResearchTitle: A genome-wide association study to understand the effect of Fusarium verticillioides infection on seedlings of a maize diversity panel
|STAGNATI, LORENZO - Università Cattolica Del Sacro Cuore|
|RAHJOO, VAHID - Seed And Plant Improvement Institute|
|SAMAYOA, LUIS - North Carolina State University|
|Holland, Jim - Jim|
|BUSCONI, MATTEO - Università Cattolica Del Sacro Cuore|
|LANUBILE, ALESSANDRA - Università Cattolica Del Sacro Cuore|
|MAROCCO, ADRIANO - Università Cattolica Del Sacro Cuore|
Submitted to: G3, Genes/Genomes/Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/7/2020
Publication Date: 5/1/2020
Citation: Stagnati, L., Rahjoo, V., Samayoa, L.F., Holland, J.B., Busconi, M., Lanubile, A., Marocco, A. 2020. A genome-wide association study to understand the effect of Fusarium verticillioides infection on seedlings of a maize diversity panel. G3, Genes/Genomes/Genetics. 10:1685-1696.
Interpretive Summary: The fungus Fusarium verticilliodes infects corn and causes ear and stalk rots, leading to lower yields and reduced grain quality. The fungus can also infect seedlings and damage the development of young maize plants as well. In this study, we evaluated the response of 267 diverse maize inbreds to infection by Fusarium verticillioides as seedlings. We identified a number of genetic variants associated with the amount of change in seedling weight or length caused by infection. More resistant lines had smaller changes in their growth due to infection. A subset of these genes are in similar genomic positions as ear rot genes, suggesting that there is some subset of genes conferring resistance to both seedling infection and adult infection.
Technical Abstract: Fusarium verticillioides which causes ear rot, kernel rot and stem rot, has been reported as the most prevalent species on maize worldwide. Kernel infection by F. verticilliodes results in reduced grain yield and quality and fumonisin contamination, and may affect seedling traits like germination rate, entire seedling length oleoptile, and seedling weight. Resistance to Fusarium ear rot of maize is a quantitative and complex trait controlled by numerous genes with small effects. In the present work, Genome Wide Association Study (GWAS) was applied for Fusarium seedling rot related traits in 267 maize lines of the maize association population using 226,446 SNP markers. Phenotypes were scored on artificially infected kernels applying the Rolled Towel Assay (RTA) and six seedling traits related to disease reaction were measured. GWAS resulted in 42 SNPs significantly associated with the traits examined. Two and 11 SNPs were associated with seedling length in inoculated and non-inoculated kernels respectively. Six and nine SNPs were also associated with seedling weight in inoculated and non-inoculated kernels respectively and one and 13 SNPs were also associated with germination rate in inoculated and non-inoculated kernels respectively. Some genes containing the significant SNPs or physically closed to them are proposed for Fusarium resistance. Some genes containing or adjacent to significant SNPs identified by GWAS in current research co-localized with some QTLs regions reported for FER and fumonisin accumulation. Linkage disequilibrium analysis revealed an additional gene not directly detected by GWAS analysis. These findings help us to understand better the complex interaction between maize and F. verticillioides.