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United States Department of Agriculture

Agricultural Research Service

Research Project: USING GENETIC DIVERSITY OF IMPROVE QUANTITATIVE DISEASE RESISTANCE AND AGRONOMIC TRAITS OF CORN Title: Genome-wide association study of quantitative resistance to southern leaf blight in the maize nested association mapping population

Authors
item Kump, Kristen -
item Bradbury, Peter
item Buckler, Edward
item Belcher, Araby -
item Oropeza-Rosas, Marco -
item Wisser, Randall -
item Zwonitzer, John -
item Kresovich, Stephen -
item McMullen, Michael
item Ware, Doreen
item Balint-Kurti, Peter
item Holland, Jim

Submitted to: Nature Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 14, 2010
Publication Date: February 1, 2011
Citation: Kump, K., Bradbury, P., Buckler IV, E.S., Belcher, A., Oropeza-Rosas, M., Wisser, R., Zwonitzer, J., Kresovich, S., McMullen, M.D., Ware, D., Balint Kurti, P.J., Holland, J.B. 2011. Genome-wide association study of quantitative resistance to southern leaf blight in the maize nested association mapping population. Nature Genetics. 43:163-168.

Interpretive Summary: Southern leaf blight is a potentially devastating disease of maize, the primary staple crop in many parts of the world. Identification of the numerous genes responsible for quantitative resistance to this disease represents an important step toward ensuring global food security. Our research relies on the tremendous genetic resources that have recently become available for complex trait analysis in maize. These include the nearly complete and well-annotated maize reference sequence, the maize Nested Association Mapping population, and the maize Haplotype Map, which provides 1.6 million DNA markers segregating in this population. We implemented a genome-wide analysis methods developed specifically for the maize Nested Association Mapping and identified specific sequence variants associated with southern leaf blight resistance throughout the genome. A high proportion of these variants are inside of, or adjacent to, genes that have been previously demonstrated to affect disease resistance in plants.

Technical Abstract: Nested association mapping (NAM) offers unprecedented power to resolve complex, quantitative traits to their causal loci. The maize NAM population, consisting of 5000 lines from 25 families representing the global diversity of maize, was evaluated for resistance to Southern leaf blight (SLB) disease, which threatens maize production in many environments. Joint-linkage analysis identified 32 quantitative trait loci (QTL) with predominantly small, additive effects on SLB resistance. Genome-wide association tests of maize HapMap SNPs were conducted by projecting founder inbred SNP genotypes onto the NAM RILs. SNPs both within and outside of QTL intervals were associated with variation for SLB resistance. Many of these SNPs were within or immediately adjacent to sequences homologous to genes previously demonstrated to be involved in plant disease resistance.

Last Modified: 10/20/2014