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ARS Home » Plains Area » Lincoln, Nebraska » Wheat, Sorghum and Forage Research » Research » Research Project #434418

Research Project: Improved Winter Wheat Disease Resistance and Quality through Molecular Biology, Genetics, and Breeding

Location: Wheat, Sorghum and Forage Research

Project Number: 3042-21000-033-00-D
Project Type: In-House Appropriated

Start Date: May 3, 2018
End Date: May 2, 2023

Objective:
Objective 1: Identify candidate viral and host genes, through use of mutational analysis, protein-protein interaction, and genomic studies for enhanced control and management of Wheat streak mosaic and Triticum mosaic viruses. Subobjective 1A: Examine virus-host interactions of Wheat streak mosaic virus (WSMV) to identify means of disruption and effect control of viral diseases. Subobjective 1B: Examine virus-virus interactions of WSMV and Triticum mosaic virus (TriMV) to identify proteins responsible for superinfection exclusion. Subobjective 1C: Examine interactions between WSMV and wheat curl mites to identify means of interrupting vector transmission. Objective 2: Develop and characterize transgenic wheat for resistance to WSMV and TriMV, and pyramid transgenes with natural resistance genes. Subobjective 2A: Develop transgenic wheat with WSMV and/or TriMV genes involved in superinfection exclusion (cross protection). Subobjective 2B: Pyramid transgenes of WSMV and TriMV with natural resistance genes, Wsm1 and/or Wsm2. Subobjective 2C: Knockout wheat curl mite transmission of WSMV by silencing WSMV-interacting mite gene(s) through RNAi approach in transgenic wheat. Objective 3: Identify, characterize, and deploy biologically active peptides and genes from the primary and secondary gene pool of wheat for resistance to viral, fungal, and bacterial diseases of wheat. Subobjective 3A: Characterize genes from perennial wheat conferring resistance to WSMV and TriMV, determine if they are unique or allelic to Wsm1 and Wsm2, and define mechanism of virus resistance. Subobjective 3B: Determine whether a truncated version of an intermediate wheatgrass chromosomal introgression would serve as an improved vehicle for deployment of Wsm1 in wheat cultivars. Subobjective 3C: Express anti-microbial peptides using TriMV-based expression vectors, and test for efficacy at control of bacterial streak in wheat. Objective 4: Develop and characterize adapted winter wheat germplasm with broad and specific disease resistance, and with improved grain nutritional quality. Subobjective 4A: Develop wheat with low levels of grain phytic acid, and effective field resistance to predominant Great Plains fungal and bacterial pathogens.. Subobjective 4B: Identify Great Plains adapted hard winter wheat germplasm with resistance to multiple forms of Ug99 stem rust. Subobjective 4C: Coordinate the Hard Winter Wheat Regional Nursery Program and use the nurseries to: 1) determine the yield potential and stability of newly developed low phytate and stem rust resistant germplasm, and 2) distribute germplasm to Great Plains breeding programs.

Approach:
The primary objectives of this project are to develop improved wheat germplasm by enhancing disease resistance and grain quality traits. The project will characterize genes of Wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TriMV) responsible for pathogenicity and vector transmission. This information will be used to develop transgenic wheat with resistance to both viruses, and to the common vector, the wheat curl mite. The project also will use TriMV to express biologically active peptides in wheat, to effect control of bacterial and fungal diseases. Natural (non-transgenic) sources of virus resistance will be used to develop and select germplasm with such resistance, and distribute it to breeding programs world-wide. The project will complete the evaluation and distribution of wheat breeding materials with resistance to Ug99 forms of stem rust, and with low levels of grain phytic acid. The latter will lead to wheat with improved mineral nutrition and diminished anti-nutrient properties. Developed germplasm will be characterized and distributed via the USDA-ARS Lincoln coordinated Winter Wheat Performance Nursery Program. The project consists of three integrated components: germplasm development and evaluation, viral genetics, and plant pathology. Molecular and conventional methodologies will be utilized, and the project scale will range from DNA molecules to field-level. The project also has extensive formal and informal collaborations enhancing our ability to conduct this research. Anticipated products include improved wheat germplasm for the wheat seed industry with value-added traits and biotic stress tolerance, and new targets to continue the laudable goal of developing host-plant resistance.