Submitted to: Journal of Heredity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/29/1996
Publication Date: N/A
Interpretive Summary: The Hessian fly is the most important insect pest of wheat in the U.S. The use of resistant wheat varieties has been the most effective control method for managing this insect. However, virulent biotypes or races of the Hessian fly have evolved that can overcome resistance and survive on resistant varieties. The evolution of virulent biotypes limits the life time (durability) of resistant varieties. In Indiana, for example, where only two generations of Hessian fly develop each year, the durability of a resistant wheat variety is limited to 8-10 years, approximately the same amount of time (10-12 years) required to develop a resistant variety. A better understanding of the genetics of the Hessian fly/wheat plant interaction would aid development of durable wheats. This research reports the study of the genetic control of virulence in the Hessian fly to wheat resistance gene H13, one of the undeployed genes for resistance that is being incorporated into new wheat varieties. Results reveal that virulenc in the Hessian fly to H13 is controlled by a single recessive gene located on a sex chromosome and linked to a white-eye trait in the adult. The linkage between virulence and eye color will facilitate the identification of molecular markers associated with the virulence gene and the location of the gene on the fly chromosome. This information will aid wheat researchers when they are incorporating resistance genes into new wheat cultivars.
Technical Abstract: Current knowledge of the genetic and molecular basis of virulence in the Hessian fly, MAYETIOLA DESTRUCTOR (Say) to resistance in wheat, TRITICUM AESTIVUM L., is inadequate to provide sustainable protection of the crop. Resistance resources are expected to be finite and research to prolong resistance is needed. More viurlent biotypes of the fly continue to emerge ein response to selection pressure from resistance genes deployed in wheat. A gene-for-gene interaction has been proposed to form the genetic basis of resistance in the Hessian fly/wheat system. The genetic control of the ability of Hessian fly to survive on resistant wheat, however, has been confined to a single published report. The present work was undertaken to test gene-for-gene resistance in the Hessian fly/wheat interaction with respect to resistance gene H13, one of the undeployed genes for resistance bing incorporated into wheat cultivars for Hessian fly protection. Results srevealed the virulent phenotype was controlled by a single recessive, sex-linked gene (H13 virulent, vir H13). Additionally, genetic analysis of avirulent/virulent phenotypes confirmed previous observations that males express only maternally derived sex chromosomes in the soma. Segregation of white and dark eye color in backcrosses revealed a disequilibrium from the expected 1:1 phenotypic ratio. This suggests the locus controlling the white-eye trait is linked in repulsion with that controlling virulence to H13. Use of the white-eye trait to facilitate identifying molecular markers linked to H13 virulence is discussed.