Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/13/2005
Publication Date: 4/10/2005
Citation: Liu, X.M., Reese, J.C., Wilde, G.E., Fritz, A.K., Gill, B.S., Chen, M. 2005. Hessian fly-resistance genes h9, h10, and h11 are mapped to the distal region of wheat chromosome 1as. Journal of Theoretical and Applied Genetics. 10:1473-1480. Interpretive Summary: Traditional breeding based on phenotypic selection is labor intensive and time consuming. It is almost impossible to pyramid multiple resistance genes if these genes have similar phenotypic reactions. Molecular breeding based on marker-assisted selection (MAS) can speed up breeding and make pyramiding multiple genes a reality. The first step for MAS is to identify reliable markers. In this research, we identified several markers that are tightly linked with Hessian fly resistance genes H9, H10, and H11. We also found that H9 and H10 are located on the short arm of wheat chromosome 1A, in stead of 5A where they were previously assigned. The correction of the chromosomal localization of these genes and the markers we identified will be very useful for MAS in Hessian fly resistance breeding in the future. The Hessian fly is one of the most destructive insect pests of wheat. Resistance genes in wheat is the most effective and cost efficient way to control this insect.
Technical Abstract: H9, H10, and H11 are major dominant resistance genes in wheat expressing antibiosis against Hessian fly (Hf) [Mayetiola destructor (Say)] larvae. Previously, H9 and H10 were assigned to chromosome 5A and H11 to 1A. The objectives of this study were to identify simple-sequence-repeat (SSR) markers for fine mapping of these genes and for marker-assisted selection in wheat breeding. Contrary to previous results, there was no linkage between H9 or H10 and SSR markers on chromosome 5A. Instead, H9, H10 and H11 were linked with SSR markers on the short arm of chromosome 1A. Both H9 and H10 were tightly linked to flanking markers, Xbarc263 and Xcfa2153, within a genetic distance of 0.3-0.5 cM. Our results also indicate that the same markers are linked with H11. Deletion bin mapping assigned these markers and genes to the distal 14% of chromosome arm 1AS, where another Hf-resistance gene Hdic (derived from emmer wheat) was also mapped previously. Marker polymorphism results indicated that a small terminal segment of chromosome 1AS containing H9 or H10 was transferred from the donor parent to the wheat line Iris or Joy, and a small intercalary fragment carrying H11 was transferred from the resistant donor to the wheat line Karen. Our results suggest that H9, H10, H11, Hdic, and the previously identified H9- or H11-linked genes may compose a cluster (or family) of Hf-resistance genes in the distal gene-rich region of wheat chromosome 1AS, and H10 most likely is the same gene as H9.