Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/14/2005
Publication Date: 9/1/2005
Citation: Liu, X.M., Brown Guedira, G.L., Hatchett, J.H., Owuoche, J.O., Chen, M. 2005. Genetic characterization and molecular mapping of a hessian fly resistance gene transferred from t. turgidum ssp. dioccum to common wheat. Journal of Theoretical and Applied Genetics. Interpretive Summary: The Hessian fly is one of the most destructive pests of wheat. Resistant wheat has been the most effective way to control this pest. The challenge for the wheat resistance strategy is that the Hessian fly can overcome resistance after a wheat cultivar is released. Therefore, we need to continually identify new sources of resistance. The present research transferred a Hessian fly resistance gene from a wild relative to aurum wheat to common wheat. Analysis indicated that this resistance gene is either a novel gene or a new allele. The identification of this gene provides breeders a new choice to generate Hessian fly resistant cultivars.
Technical Abstract: A Hessian fly (Hf) [Mayetiola destructor (Say)] resistance gene, Hdicoccum, was previously identified from an accession of German cultivated emmer wheat (Triticum turgidum ssp. dicoccum) PI 94641, and was transferred to the Hf-resistant hard red winter wheat germplasm KS99WGRC42. The Hdicoccum gene is partially dominant and temperature-insensitive, with a high level of homogeneous antibiosis. Six microsatellite (simple sequence repeats, SSR) markers (Xgdm33, Xgwm136, Xcfa2153, Xpsp2999, Xgwm33, and Xbarc263) were linked to the Hdicoccum gene on the short arm of wheat chromosome 1A. Flanking markers Xgwm33 and Xcfa2153 were mapped at distances 0.6 cM proximal and 1.4 cM distal, respectively. Deletion analysis assigned the Hdicoccum gene to the distal 14% of chromosome 1AS. Two known Hf-resistance genes located on chromosome 1A, H5 and H11, confer resistance to Hf biotype GP but exhibit susceptibility to biotype L, whereas the Hdicoccum gene confers resistance to both biotypes. Therefore, this is either a new gene, or an allele variant of either H5 or H11. Marker analysis revealed that a very small intercalary chromosomal segment containing Hdicoccum was transferred from emmer wheat to KS99WGRC42. This is the first Hf-resistance gene derived from emmer wheat that has been mapped and characterized.