Map-based Cloning Reveals the Origin of Fhb1 Gene in Wheat

Fhb1 (syn Qfhs.ndsu-3BS) is the most consistently reported QTL against the devastating Fusarium Head blight disease in wheat and has been reported to provide up to 60 % resistance in various mapping studies. Fhb1 provides high level of type-2 resistance and is found in a few Chinese landraces only, from where it has been deployed worldwide. Fhb1 from Chinese cultivar Sumai 3 has been cloned and validated in our Laboratory. Cloning of Fhb1 opens up new avenues in understanding the origin and the mechanism of its action against FHB. Based on phenotyping and haplotyping, the origin of Fhb1 is known to be restricted to a few Chinese landraces. Using sequence information obtained from the cloned gene, we studied the origin of Fhb1 in wheat and and related species. We sequenced Fhb1 gene from a large set of diploid A- genome, S- genome and D- genome accessions. Additionally, we sequenced it from a core set of tetraploid wheat species available with Wheat Genetics Resource Center at Kansas State University including T. turgidum and T. timopheevii. The findings of the association studies of Fhb1 on wild and related germplasm of wheat research will be presented.