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United States Department of Agriculture

Agricultural Research Service

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Research Project: Enhancement of Wheat Through Genomic and Molecular Approaches

Location: Genomics and Gene Discovery

Project Number: 5325-21000-019-00
Project Type: Appropriated

Start Date: May 13, 2013
End Date: May 12, 2018

Objective:
The long-term goal of this project is to understand and control the genetic and molecular basis of wheat quality traits conferred both by the seed proteins and other factors contributing to seed formation (directly or indirectly through plant fitness). Objective 1: Generate novel genetic and genomic sequence information and resources for wheat breeding. • Sub-objective 1.A. – Mapping of the wheat D-genome. • Sub-objective 1.B. – Sequencing of the wheat 3D chromosome. • Sub-objective 1.C. – Completion of the sequencing of the complete set of wheat prolamin loci. Objective 2: Characterize genes and mechanisms for important wheat traits such as baking quality and cold temperature tolerance. • Sub-objective 2.A. – Molecular dissection of wheat HMW-subunit contributions to baking quality. • Sub-objective 2.B. – Application of molecular, genomic, and bioinformatic tools to developmental and metabolic traits.

Approach:
Objective 1: Generate novel genetic and genomic sequence information and resources for wheat breeding. • Sub-objective 1.A. - Map the wheat D-genome using radiation hybrid wheat lines, constructing a linkage map of the D-genome, and constructing a physical map of the wheat genome through a minimum-tiling-path (MTP) of bacterial-artificial-chromosomes (BACs). Integration of all such maps once mapping is complete. • Sub-objective 1.B. – Sequence the MTP of the wheat 3D chromosome using Roche 454 technology. The chromosome sequence will be annotated along with collaborators and made available to public databases. • Sub-objective 1.C. – Sequence with Roche 454 technology and analyze wheat contiguous genomics regions spanning the prolamin loci responsible for wheat quality characteristics to further understanding of the evolution, expression, and regulation of prolamin genes in wheat. Objective 2: Characterize genes and mechanisms for wheat traits focusing on two important traits; i.e., baking quality and cold temperature tolerance. • Sub-objective 2.A. – Molecular dissection of wheat HMW-subunit contributions to baking quality. The three approaches under this sub-objective involve alterations in seed prolamin structure, alteration in total seed prolamin composition, and studying mechanisms for processing of wheat prolamins during seed development. Experimental approaches will include laboratory studies of modified prolamins and mutagenized wheat lines with altered prolamin compositions and the effects on dough properties. Prolamin sub-cellular processing will be studied using modified prolamins with specific molecular tags. • Sub-objective 2.B. – The application of molecular and genomic tools to cold temperature tolerance. The specific goal is to identify the genetic factors critical to the development of wheat cold temperature tolerance. The approach will utilize genetic stocks, double haploid mapping populations, and genotype-by-sequencing to identify genes involved in cold-temperature tolerance. The objectives will be accomplished with the following approaches: 1) Integrate genetic, physical, and radiation hybrid maps of Ae. tauschii to provide a foundational framework for sequencing the wheat D genome. 2) Contribute to a collaboration to sequence the minimum tiling path (MTP) of the Ae. tauschii 3D chromosome. 3) Sequence and analyze contiguous genomics regions spanning the prolamin loci of wheat. 4) Study the structure, composition, and processing of seed prolamin correlate changes in structure and composition with wheat quality characteristics. 5) Map and characterize genes involved in cold tolerance by testing for correlations with cold temperature tolerance phenotype in wheat.

Last Modified: 7/31/2014
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