Location: Wheat Health, Genetics, and Quality Research
Project Number: 2090-43440-008-000-D
Project Type: In-House Appropriated
Start Date: May 6, 2020
End Date: May 5, 2025
Objective:
This project is focused on enhancing wheat grain quality in the Western U.S. and elsewhere by providing the knowledge and means to breed better quality wheat varieties. We will achieve three primary objectives: 1) Resolve the underlying genetics of kernel texture (grain hardness), 2) develop wheat germplasm with lower and higher levels of starch amylose, and 3) collaboratively develop superior and novel wheat cultivars for the Western U.S. to ensure that millers and food processors have superior food ingredients, farmers grow high-value crops and consumers have appealing, nutritious and less expensive foods. Production of superior wheat cultivars makes the U.S. more competitive abroad and U.S. agriculture more sustainable. Objectives 1 and 2 are separated each into two Subobjectives, 1A involves the role of puroindolines, and other kernel texture loci derived from Aegilops tauschii, Extra-Soft, and Super-Soft germplasm. Subobjective 2B involves Granule bound starch synthase I and Starch branching enzyme IIa to reduce and increase amylose, respectively. Subobjectives 1B and 2B involve developing germplasm and genetic stocks with novel traits.
The above objectives represent multiple, interrelated issues of improving wheat quality, functionality, and marketability that have been identified by the PNW Wheat Quality Council over the last 20+ years during their annual collaborative tests. Project objectives and linkages among other projects that contribute to achievement of the overall project goal are illustrated in Figure 1. Guidance and input to the project plan come from a number of sources. Peer science guides the direction and evaluates the quality of much of the research on end-use quality traits. By synthesizing the needs of the end-use sector and state-of-the-art science, cutting-edge, relevant research is targeted. The result is embodied in Objectives 1 and 2, and the traits that will be studied. By extension and creativity, novel traits are envisaged and studied (e.g. ‘Super Soft’ kernel trait and soft durum). The outcome/products are improved cultivars that have superior and predicable end-use quality, genetic stocks, novel germplasm and new knowledge. In guiding the breeder line evaluation (Objective 3), the PNW Wheat Quality Council provides direct input from a large and representative number of end-users, cereal scientists, and stakeholders. New varieties are evaluated and discussed in an open forum. These discussions provide for establishing specific testing methodologies and strategies as well as specific target values.
Approach:
Objectives 1 and 2: Extend our understanding of the role(s) of kernel hardness, puroindolines and other genes in wheat grain quality and utilization. Hypothesis: Different gene sequences of puroindoline a and b modulate different levels of kernel hardness; additional novel non-puroindoline genes/loci affect kernel texture. Extend our understanding of the role(s) of starch composition, including Waxy and high amylose genes on wheat grain quality and utilization. Hypothesis: Starch composition, i.e., amylose: amylopectin ratios can be manipulated via null mutations in GBSSI and SbeIIa; wheat with different starch composition provides novel processing and nutritional opportunities.
Puroindoline a, Puroindoline b and Grain softness protein-1 genes are sequenced. Aegilops tauschii and synthetic hexaploid wheats are obtained from germplasm collections. Synthetics are evaluated for kernel texture phenotype. Unique lines are crossed to Alpowa soft white spring wheat. The genetic basis for Extra-Soft and Super Soft genes hexaploid and durum germplasm will be determined. Develop germplasm and genetic stocks with unique starch biosynthesis genes. Develop, register and release spring wheat NILs for all eight haplotypes of GBSSI and SbeIIa; develop soft white winter wheat germplasm with the GBSS 4A null allele. The unique synthetics, backcross NILs, and starch mutants will be grown for milling and baking evaluations. Germplasm will be released and registered.
Contingencies: The experiments with synthetics are dependent on obtaining germplasm from the USDA and other repositories and having greenhouse space available. All other germplasm is currently housed in the WWQL. Successful crossing and plant growth, equipment being operational, etc. are essential. Marker density will need to be sufficient to detect the loci of interest. The effect of the environment on phenotypic expression of kernel texture will be addressed through replicated trials over two or more environments.
Objective 3: Evaluate and report the milling and end-use quality of PNW wheat under a Congressionally-designated direct mission of service, with the goal to develop and release new wheat cultivars to growers. Most tests follow AACCI Approved Methods. Standard methods include SKCS, Quadrumat milling, Solvent Retention Capacity, SDS sedimentation, Mixograph, cookie and bread baking.
