Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/9/2007
Publication Date: 3/27/2007
Citation: Xu, S.S., Cai, X., Harris, M.O. Identification and Genetic Characterization of Hessian Fly Resistance in Synthetic Wheat. Meeting Abstract. 2007 ESA-NCB Annual Meeting March 25-28, 2007 Winnipeg, Manitoba, Canada.
Technical Abstract: The Hessian fly (Mayetiola destructor) is an important insect pest attacking wheat and, each year, causes extensive yield losses in the United States. Plant resistance via single resistance (R) genes has provided excellent control of the Hessian fly for over 50 years. However, because the Hessian fly can evolve virulence to the R gene deployed in wheat, there is a need for a large pool of effective R genes. Synthetic hexaploid wheat (SHW), derived from a tetraploid wheat (T. turgidum) ' Aegilops tauschii hybrid, has proven to be a good source of resistance genes for both the Hessian fly and important wheat diseases. The objectives of our study were to identify Hessian fly resistance genes in the SHW lines developed at the Northern Crop Science Laboratory (NCSL) of USDA-ARS and the International Maize and Wheat Improvement Center (CIMMYT) and genetically characterize the resistance genes. We screened 161 SHW lines along with their durum wheat (T. turgidum ssp. durum) parents for reaction to Hessian fly biotype Great Plain (GP) and identified 29 resistant lines. The resistance genes in two of the resistant SHW lines (SW8 and SW34) were further characterized through allelism tests and molecular mapping. Allelism tests indicated that resistance genes in SW8 and SW34 were allelic to H26 and H13 or corresponded to paralogs at both loci, respectively. The H26 locus was assigned to chromosome 3D through molecular analyses in this study rather than 4D as previously determined by monosomic analyses. Linkage analysis and physical mapping positioned the H26 locus to the chromosomal deletion bin 3DL3-0.81-1.00. Meanwhile, mapping of the resistance gene in SW34 verified the previous assignment of the H13 locus to chromosome 6D. The resistant SHW lines identified in this study provide excellent sources of resistance to Hessian fly and should be useful for both the development of durable resistant cultivars and the genetic and evolutionary studies of resistance genes. The molecular markers linked to the Hessian fly resistance genes will facilitate map-based isolation of the resistance gene and selection of resistance during the breeding process.