Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/28/1994
Publication Date: N/A
Citation: Interpretive Summary: The Hessian fly, which is a major pest of wheat, has been effectively controlled by resistant wheat varieties for over 30 years. During this period, however, fly strains, or biotypes, have evolved that can survive on and injure wheat varieties with resistance genes. New resistance genes have been identified and incorporated into improved wheat lines that are effective against resistance-breaking (virulent) biotypes, but with time, these genes also may be reduced in effectiveness unless varieties are developed with more durable forms of resistance. One approach to improving durability of resistance is to incorporate several genes in wheat varieties, particularly genes that control different plant responses to the Hessian fly. However, in order to be certain that all resistance genes are retained in breeding lines during development of wheat varieties, researchers need a rapid method to identify the presence of the individual genes. This research describes investigations to identify DNA (molecular) markers on the wheat chromosome that can be used to confirm the presence of specific genes by biochemical methods. A marker associated with the Hessian fly resistance gene H9 was identified and determined to co-segregate with H9 in second generation progeny of a cross between a susceptible and resistant parent. The marker also remained associated with the H9 gene when the gene was incorporated into different common and durum wheat parents. This research is an important step in developing the means to identify multiple genes in wheat breeding lines and cultivars and improving durability of resistance to Hessian fly.
Technical Abstract: The Hessian fly, [MAYETIOLA DESTRUCTOR (Say)] is a major pest of wheat (TRITICUM AESTIVUM L.) and genetic resistance has been used effectively over the past 30 years to protect wheat against serious damage by the fly. To-date, 25 Hessian fly resistance genes, designated H1 to H25, have been identified in wheat. With near-isogenic wheat lines differing for the presence of an individual Hessian fly resistance gene, in conjunction with random amplified polymorphic DNA (RAPD) analysis and denaturing gradient gel electrophoresis (DGGE), we have identified a DNA marker associated with the H9 resistance gene. The H9 gene confers resistance against biotype L of the Hessian fly, the most virulent biotype. The RAPD marker co-segregates with resistance in a segregating F2 population, remains associated with H9 resistance in a number of different T. AESTIVUM and T. DURUM L. genetic backgrounds, and is readily detected by either DGGE or DNA Agel-blot hybridization.