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United States Department of Agriculture

Agricultural Research Service

Related Topics

Research Project: Genetic Improvement of Durum and Spring Wheat for Quality and Resistance to Diseases and Pests

Location: Cereal Crops Research

Project Number: 5442-21000-037-00
Project Type: Appropriated

Start Date: Apr 15, 2013
End Date: Apr 14, 2018

Objective:
The proposed research involves the use of genetics and genomics to gain understanding of the genes associated with mechanisms of disease resistance or susceptibility and end use quality, and the identification, characterization, and development of genetic stocks, germplasm, and tools for the improvement of wheat and other small grains. Specific objectives are: 1. Identify new genes and sources for resistance and end-use quality in wheat. 1A. Identify new sources of Hessian fly resistance among wheat wild relatives of the Aegilops genus and newly developed synthetic hexaploid wheats. 1B. Identify new sources of stem rust resistance among wheat relatives of the Thinopyrum genus and newly developed synthetic hexaploid wheats. 1C. Identify new sources of Fusarium head blight (FHB), tan spot, and Stagonospora nodorum blotch (SNB) resistance among newly developed synthetic hexaploid wheats. 1D. Identify novel genes for resistance to stem rust, tan spot, SNB, and Hessian fly among the National Small Grains Collection and a collection of domesticated emmer accessions using association mapping. 1E. Identify novel genes for end-use quality among entries of the Uniform Regional Nursery using association mapping. 2. Identify and develop molecular markers for rusts, necrotrophic diseases, and pre-harvest sprouting in wheat. 2A. Determine the chromosomal locations of novel genes conferring sensitivity to newly identified host-selective toxins produced by S. nodorum using molecular markers. 2B. Develop molecular markers suitable for MAS of the S. nodorum toxin sensitivity genes Snn3-B1 and Snn3-D1 through genomic analysis and fine-mapping. 2C. Determine the chromosomal location of a new Ug99 stem rust resistance gene using molecular markers. 2D. Develop markers and populations for the fine-mapping and initiation of the map-based cloning of the Ug99 stem rust resistance gene Sr47. 2E. Develop molecular markers suitable for MAS of pre-harvest sprouting resistance QTLs on chromosome 2B in tetraploid wheat. 3. Characterize the genetic mechanisms of resistance involved in wheat-necrotrophic pathogen interactions. 3A. Determine the structural and functional diversity of the Tsn1 gene among accessions of the wild wheat ancestor Aegilops speltoides. 3B. Identify genes and/or genetic mechanisms involved in the Tsn1-ToxA interaction. 3C. Characterize the structure and function of families of Pr-1 and Pr-2 genes in wheat. 4. Develop genetic resources and tools for the improvement of wheat and other small grains. 4A. Develop HRSW lines nearly isogenic for S. nodorum toxin sensitivity genes. 4B. Develop adapted solid-stem durum wheat germplasm for resistance to sawfly. 4C. Develop durum and wheat germplasm with FHB and stem rust resistance. 4D. Develop a reference SNP map for durum wheat. 4E. Develop a SNP marker set for MAS in wheat. 4F. Provide genotyping services for barley, wheat, and oat varietal development.

Approach:
Durum and hard red spring wheat (HRSW) varieties with improved end-use quality and resistance to abiotic and biotic stresses are needed to meet the nutritional demands of the world’s growing population. This challenge must be met through the discovery and deployment of genes for disease resistance and traits that effect quality such as kernel texture, protein content, flour yield, dough strength, and baking performance. In this project, we will identify new sources of resistance to diseases and pests, and improved quality. Molecular mapping populations will be generated and used to identify genes and quantitative trait loci governing resistance to Stagonospora nodorum blotch, stem rust, and pre-harvest sprouting. This work will yield knowledge of the genetic mechanisms controlling these traits, the development of markers for marker-assisted selection, and genetic stocks and germplasm useful forgene deployment. Additional work on the molecular characterization of the genes and genetic pathways associated with wheat-necrotrophic pathogen interactions will be conducted as part of this project and will yield basic knowledge useful for devising novel strategies for developing crops with resistance to necrotrophic pathogens. Finally, genetic resources and tools for the development of improved wheat and durum cultivars will be generated, including stocks for the genetic analyses of Stagonospora nodorum blotch susceptibility genes, adapted germplasm with resistance to sawfly, Fusarium head blight, and stem rust, and high-throughput molecular marker sets for genomic selection in durum and common wheat. In addition, genotyping services will be provided to regional wheat, durum, barley, and oat breeders to expedite the development of improved varieties.

Last Modified: 7/30/2014
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