Monday, November 5, 2007 - 2:45 PM
80-4
New Microarray-Based Tools to Relate Genes to Traits for Wheat Improvement.
Daryl J. Somers, Mark C. Jordan, and Travis Banks. Agriculture and Agri-Food Canada-Cereal Research Centre, 195 Dafoe Rd, Winnipeg, MB R3T 2M9, Canada
Genomics is accelerating the development of tools for molecular breeding of crops. Microarrays represent a vast resource of different genes and gene sequence information that can be examined for 1) functional genes controlling a desirable trait or 2) genetic markers. The search for genetic markers is underpinned by mapping. Thus, our microarray approach uses typical bi-parental segregating wheat populations or well characterized collections of wheat that can be used for association genetics. When the gene expression profile is generated for a segregating population with replication, “Gene Expression Markers” (GEMs) and “Single Feature Polymorphisms” (SFPs) can be discovered. The GEMS and SFPs translate into useful genetic markers that are employed for QTL analysis. Further, the GEMs and SFPs are derived from genes, thus knowledge on the physical location of genes and chromosome regions controlling gene expression is generated. We are engaged in a project to merge gene expression profiling and marker development with seed quality and agronomic performance data, all generated from replicated field studies. The microarray platform is the Affymetrix Wheat Genome Array which holds >60,000 expressed genes represented by 605,000 individual 25 bp probes, or features. The RNA samples are taken from a segregating doubled haploid population (AC Domain/RL4452) in early seed development, 5 days post anthesis. With this genomics/genetics platform, we have mapped 100’s of individual gene expression patterns as well as SFPs. This presentation will summarize this progress and demonstrate the utility and future directions of this new genomics tools for wheat improvement. This information will be useful in devising strategies to sequence genome regions which contain important traits in complex unsequenced genomes such as wheat.