Genomics for wheat improvement

Abstract

The ability to meet the demands of global food production will require efficient means to develop modern cultivars adaptable to a range of adverse environmental conditions in marginal wheat production zones. Breeding programs will be relying on the tools used to track allelic combinations contributing to trait variation through DNA marker-assisted selection and efficient selection of genotypes expressing desirable phenotypes in target environments. The recent developments in wheat genomics have provided resources to develop new molecular markers and strategies for genetic analysis and identification of marker-trait associations. Included are new DNA marker technologies capable of developing high resolution genetic maps and QTL mapping allowing detection of trait variation at specific loci. The ability to locate the chromosomal region associated with phenotypic variation provides a leading edge towards developing functionally-associated markers (FAM) to track alleles in a breeding program. Map-based cloning, comparative genomics and sequencing the wheat genome provides current and future opportunities for discovering genes responsible for trait variation. Determining the function of newly discovered genes will allow their effective use in wheat improvement as FAM markers for marker-assisted breeding. Therefore, transgenic plants overexpressing or silencing genes by RNA interference (RNAi) and non-transgenic approaches such as virus-induced gene silencing (VIGS) and Targeting Induced Local Lesions IN Genomes (TILLING) provide strategies to determine gene function and their effects on phenotypic variation. Transgenic wheat plants and TILLING approaches also has the advantage in developing potential new varieties but the latter would be the only option in countries where the release of genetically modified wheat is constrained. © 2009 Springer Science+Business Media B.V.