Genetic Architecture of Maize and Teosinte

PI Edward Buckler (Cornell University/USDA-ARS)

CoPIs: John Doebley (University of Wisconsin - Madison), Sherry Flint-Garcia and Michael D. McMullen (University of Missouri - Columbia/USDA-ARS), James Holland (North Carolina State University/USDA-ARS), Stephen Kresovich and Qi Sun (Cornell University)

Senior Personnel: Jeffrey C. Glaubitz and Theresa Fulton (Cornell University)

Genetic architecture is the constellation of gene effects and interactions that underlie variation in a quantitative trait. Essentially, genetic architecture is the map between phenotype and genotype. Understanding variation in genetic architecture is key to understanding evolution, manipulating species for a sustainable agriculture, and preserving variation as species adapt. This project will improve our understanding of the genetic architecture of complex traits in maize and its wild relative, teosinte. Maize has a combination of life history, economic and societal value, and genetic tools that make it uniquely suited to studying genetic architecture. The project will identify genes that control domestication traits and three key agronomic traits: flowering time, plant height, and kernel quality. Genetic linkage, association, and fine mapping analyses will be performed on the largest and most diverse set of mapping families publicly available for any species. A large series of isogenic lines will be used to characterize allelic series and epistatic interactions. The genetic architecture of each of the four trait groups will be compared and contrasted, and the influence of recombination and past domestication bottlenecks on the genomic distribution of functional diversity will be examined. Finally, the ability of genetic architecture-based models to predict phenotype will be evaluated in a broad range of germplasm, including elite US hybrids. This project will take a step toward the ultimate goal of predicting phenotype from genotype.

Broader Impacts

Maize has the highest production of any crop in the world, and plays a central role in all of US agriculture and food production. Maize also has the greatest molecular and phenotypic diversity among crop species. This genetic diversity enabled domestication and is key for future maize improvement. Understanding maize genetic architecture will accelerate the breeding of future crops. In addition, this project will generate valuable germplasm resources and develop genomic tools to access and utilize maize and teosinte diversity. These resources will be used by many other research groups to dissect numerous other traits and facilitate marker assisted breeding, allele mining, and genetic analysis. Project resources will be made available to the public through a project website (www.panzea.org), integration with community websites (Gramene, www.gramene.org; MaizeGDB, www.maizegdb.org), and stock centers (Maize Genetics Cooperation Stock Center, maizecoop.cropsci.uiuc.edu; CIMMYT, www.cimmyt.org; North Central Regional Plant Introduction Station). Maize is also an excellent system for teaching about evolution, genetics, and agriculture. Outreach activities will target four audiences: (1) the general public and students through a traveling museum exhibit on maize domestication, diversity and improvement, (2) high school teachers through an enrichment course with North Carolina Agriculture & Technical State University, (3) collaborative science through an African Scientist Fellowship at Cornell's Institute of Genomic Diversity (www.igd.cornell.edu), and (4) undergraduate students through mentoring and research opportunities.