Identification, cloning and mapping of avirulence-linked molecular markers from the Hessian fly

Stanley Dean Rider, Purdue University

Abstract

The Hessian fly has an intimate genetic relationship with wheat, and the two species have co-evolved. The plant has developed genes that allow it to resist infestation by the fly. The fly has developed mutations in avirulence genes that allow it to overcome this resistance. This interaction has not been characterized at the molecular level, and much is to be learned about the interaction if durable resistance to the Hessian fly is to be developed into wheat cultivars. We are in the process of identifying and cloning the genes from the fly that are responsible for inducing a resistance response in the plant. A direct, map-based approach is being pursued because little biochemical information is available about the fly-wheat interaction. A genetic map of the Hessian fly was constructed to aid in predicting the potential success of a positional cloning approach, and to aid in the acquisition of molecular markers for Hessian fly avirulence loci. The Hessian fly has a relatively small genome (98 megabases, 545 cM) and a relatively high rate of recombination. About 180 kb represents one centimorgan of recombination. Thus, map-based cloning in the Hessian fly is feasible. Molecular markers were identified that are within walking distance of the vH13 locus—the locus that confers avirulence to the H13 wheat resistance gene. Positional cloning of this avirulence locus is underway.

Degree

Ph.D.

Advisors

Stuart, Purdue University.

Subject Area

Entomology|Molecular biology

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