Molecular and Functional Diversity in the Maize Genome

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

In 2001, maize became the number one production crop in the world, and current US maize production is almost four times wheat and rice production combined. Maize (or corn) is also the single most diverse crop species, containing tremendous variation in morphological and physiological traits and extensive polymorphism in its DNA sequences. This exceptional diversity allows maize to be cultivated in a range of environments including parts of Africa, the Amazonian rainforest, Arizona deserts, the Gaspe peninsula in Canada, and the Andes Mountains at heights above 3500 m elevation. The challenges for modern biologists are to describe the genes that control the diverse phenotypes and adaptation of maize, to identify the useful variants (alleles) at these genes, and to establish a high-throughput, high-resolution platform for finding and evaluating allelic variation throughout the genome and the breadth of the gene pool. This project will meet these challenges. First, the project will perform marker discovery for 1000 genes in diverse maize inbred and teosinte lines to identify an unbiased set of markers for molecular diversity analysis. Second, the project will analyze the sequences of 4,000 genes in diverse types of maize and wild maize (teosinte). This data will provide a direct measure of the amount and distribution of molecular variation in the maize genome and enable the identification of genes that have been selected by humans over the past 10,000 years to adapt maize to diverse environments and to improve the agronomic performance of maize. Third, the project will include functional assays of 750 genes in order to determine which traits they control and at which alleles these genes confer the best agronomic qualities. This work will produce two major resources: (1) a large database of validated molecular polymorphisms throughout the genome, and (2) a set of maize and teosinte lines that can be used for gene mapping for almost any trait. These results and products will be made available to a wide range of researchers through public depositories such as the Maize Genetics Cooperation Stock Center (http://www.ag.uiuc.edu/maize-coop), North Central Regional Plant Introduction Station (http://www.ars-grin.gov/ars/MidWest/Ames/), Gramene (http://www.gramene.org) and Genbank (http://www.ncbi.nlm.nih.gov/Genbank/). Additionally, the project will make this research accessible to a wide range of people through outreach programs. The project will focus on transmitting the excitement of science and knowledge of maize to students in rural schools and through mentoring programs, with an emphasis on broadening participation.