Discovery and deployment of molecular markers linked to fusarium head blight resistance: An integrated system for wheat and barley

Fusarium head blight (FHB), caused by Fusarium graminearum Schwabe [teleomo rph Gibberella zeae (Schwein.)], is a devastating disease that reduces yiel d, quality and economic value of wheat (Triticum aestivum L.) and barley (H ordeum vulgare L.). The quantitative nature of resistance and tremendous ex pense of phenotypic screening indicate that the identification of resistant genotypes in breeding populations might be expedited by molecular markers. The markers must be polymorphic and informative across populations for the m to be used by breeders. Worldwide, several groups are mapping genes for F HB resistance in wheat and barley and marker discovery is underway. Althoug h these markers may be validated and made breeder-friendly by the laborator ies that developed them, the urgency of the FHB situation in North America and worldwide requires efforts to accelerate this process. To take advantag e of economies of scale and accelerate information sharing, we propose the establishment of a National Genotyping Center (NGC) for barley and wheat. T he immediate objective of the NGC would be to identify and deploy breeder-f riendly markers linked to FHB resistance quantitative trait loci (QTL). Ove r time, we propose that several regional genotyping centers will he establi shed to correspond to regional and market class needs. The NGC would provid e the regional centers with high throughput marker systems that would be us ed to genotype plants in breeding populations submitted by plant breeders. For the long term, we expect that the focus of the NGC will extend beyond F HB resistance, and that a key objective will be the development of new tech nologies to enhance plant breeding efforts.