ASSOCIATION OF A DNA MARKER WITH HESSIAN FLY RESISTANCE GENE H9 IN WHEAT

The Hessian fly [Mayetiola destructor (Say)] is a major pest of wheat (Triticum aestivum L.) and genetic resistance has been used effectivel y over the past 30 years to protect wheat against serious damage by th e fly. To-date, 25 Hessian fly resistance genes, designated H1 to H25, have been identified in wheat. With near-isogenic wheat lines differi ng for the presence of an individual Hessian fly resistance gene, in c onjunction with random amplified polymorphic DNA (RAPD) analysis and d enaturing gradient-gel electrophoresis (DGGE), we have identified a DN A marker associated with the H9 resistance gene. The H9 gene confers r esistance against biotype L of the Hessian fly, the most virulent biot ype. The RAPD marker cosegregates with resistance in a segregating F-2 population, remains associated with H9 resistance in a number of diff erent T. aestivum and T. durum L. genetic backgrounds, and is readily detected by either DGGE or DNA gel-blot hybridization.