Location: Wheat Health, Genetics, and Quality Research
2022 Annual Report
Objectives
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.
Progress Report
Progress was made on all three objectives, which fall under NP306.
In support of Objective 1, research continues on the utilization of genetics to identify new commercial end-uses of Western wheat. Although flour and baking analyses are critical components of a wheat breeding program, early-generation selection is also highly efficient and useful. At early generations there is typically not sufficient grain to mill and perform flour and baking evaluations. In collaboration with Washington State University, a large study was performed examining the effectiveness of genomic selection for optimized breeding for end-use quality traits in soft wheat. Several areas of high genomic prediction accuracies were found, which will allow those models to be used in the future for greater genomic selection at an earlier generation of wheat. Along with this work on genomic selection, machine learning and deep learning models were explored with similar high accuracy to the optimized genomic selection.
Additionally, in support of Objective 1, several aspects of soft durum quality were examined using several different genetic introgressions and mapping populations. These introgressions included the strong gluten variant at the High Molecular Weight Glutenin Subunit (HMW-GS) Glu-D1 gene. These genes occur in hexaploid on the short arm of Chromosome 1D and were introgressed into soft durum. There are HMW-GS on the A and B genome but those on the D genome have the greatest influence over gluten strength of all HMW-GS. The two haplotypes examined showed how gluten strength in soft durum could be modulated to “optimally strong” and “overly strong” for increased use of soft durum in a baking application.
In support of Objective 2, collaborative research with Washington State University resulted in advancement of High Amylose Cadenza lines by single seed descent (SSD) after the haplotypes were verified for the SBEIIa genes which control the amylose/amylopectin ratio in grain. These genes can be manipulated to produce a range amylose from high amylose to waxy wheat which possesses low or no amylose. These new lines allow us to explore novel uses of low/no amylose wheat such as puffing. A soft white spring wheat showing heterogeneity for the Waxy 4A allele was selected for the partial Waxy trait and progeny continued to be screened to verify the null 4A allele.
In support of Objective 3, research continues in evaluating and reporting the milling (processing and intrinsic end-use quality) parameters of Western Soft White Common and Club (spring and winter), Hard Red Winter and Spring, and Hard White Winter and Spring Wheat commercially-viable germplasm as part of the Congressionally-designated direct mission of service (non-hypothesis driven). A total of ca. 5,000 experimental wheat germplasm and commercial cultivars were evaluated for breeding programs in the western United States.
Accomplishments
1. High-throughput analysis of grain properties of peas. Efficient and timely pulse quality research requires consistent and rapid methods of evaluation. Some traits that are required for high quality pulses are sound seeds, specific seed weight and color, and intact seeds. These quality traits are important not only for the Federal Grain Inspection Service (FGIS) grade, but also for customer specifications for whole or split peas, and for milling applications. Two ARS scientists in Pullman, Washington, have developed protocols using a seed-image analyzer to quickly evaluate pea samples for thousand-seed weight, seed dimensions, volume, color, broken seeds, and other traits. The ability to rapidly evaluate pulse grain properties is an important and substantial step in developing a robust pulse end-use quality evaluation program.
2. High Molecular Weight Glutenin Subunit characterization in Pacific Northwest wheat germplasm. High Molecular Weight Glutenin Subunits (HMW-GS) in wheat have profound effects on both hard and soft wheat quality. While the effects of HMW-GS on hard wheat quality have been studied, less research has been done on the different HMW-GS profiles that key determinants of the best uses for soft wheat flour; cookies and cakes require a “weaker” glutenin profile, whereas crackers and pancakes require a “stronger” glutenin profile. An ARS scientist at Pullman, Washington, characterized the HMW-GS profile of the soft white wheats commonly grown in the western region. Creating a running database of these HMW-GS profiles for soft white wheat allows the export customers to source wheat based on their specific products and provides needed information to support the overall export market.
3. Pulse pasta using peas and lentils compared to semolina pasta. There is an increased demand for pulse-based products because of their high protein and fiber content along with being gluten-free. Pasta is traditionally made from semolina, but in this work in collaboration with Washington State University, an ARS Scientist in Pullman, Washington, extruded spaghetti using pea flour, lentil flour, and semolina separately. The spaghetti made from 100% pulse flour had shorter cooking times and similar quality characteristics to the semolina pasta. Pulse flours are a valuable ingredient for making highly nutritious, gluten-free pasta.
4. Genomic selection for soft wheat end-use quality. Phenotyping wheat for end-use quality is most commonly performed at later stages of the breeding-line cycle and requires large grain samples. End-use quality issues become apparent at this later stage, but at that point many resources have been invested into potential breeding lines. Two genomic selection models were created by ARS scientists at Pullman, Washington, with scientists at Washington State University to more accurately predict end-use quality for early-generation soft wheat breeding lines. This genomic selection allows for earlier prediction of a breeding line’s potential end-use quality and lines can either be advanced or discarded earlier in the breeding-line cycle, making the process more resource-efficient.
5. Gluten strength in soft durum wheat. Soft durum has been used to bake soft wheat products like Pizza crust and hearth bread, but has been less optimal for pan-bread baking. The soft durum lacks the D genome where the most critical gluten protein genes reside. ARS scientists at Pullman, Washington, introgressed the High-Molecular Weight Glutenin Subunits (HMW-GS) at the Glu-D1 locus from wheat chromosome 1D for stronger or weaker gluten strength into soft durum to create populations with and without these weaker and stronger gluten strength genes. Bread volumes from the Glu-D1 2x+12y gene showed excellent promise for optimal pan-bread baking in a soft durum background with similar bread loaf volume to a hard hexaploid wheat. The Glu-D1 5x+10y gene introgression had overly-strong gluten for bread, but could be used in a blend. Soft durum is a novel ingredient and improving gluten strength increases the versatility of this unique product.
6. Field pea traits and variation. The assessment of end-use quality for peas requires an understanding of the relationship among traits measured on different types of field peas. Some of these important traits are dehulling efficiency, protein content of dehulled peas, starch lost during dehulling, and extractability of protein. Isolation of Pea protein is a desired end use for peas and there is a need to identify traits contributing to improved protein isolation and to evaluate the variation of protein among pea genotypes. A large genetic by environment study was undertaken by ARS scientists at Pullman, Washington, to assess these qualities, finding that a large amount of pea seed is lost as seed coat, starchy byproduct, and soluble components in protein extraction. Understanding the factors contributing to this loss of starchy material from peas during dehulling and protein extraction furthers processors’ understanding of, and plans for, how to mechanically and chemically handle peas for optimum end-use.
Review Publications
Daba, S.D., Morris, C.F. 2022. Pea proteins: Variation, composition, genetics, and functional properties. Cereal Chemistry. 99(1):8-20. https://doi.org/10.1002/cche.10439.
Morris, C.F. 2021. Bread-baking quality and the effects of Glu-D1 gene introgressions in durum wheat (Triticum turgidum ssp. durum). Cereal Chemistry. 98(6):1151-1158. https://doi.org/10.1002/cche.10473.
Kiszonas, A., Ibba, M., Boehm Jr., J.D., Morris, C.F. 2021. Effects of Glu-D1 gene introgressions on soft white spring durum wheat (Triticum turgidum ssp. durum) quality. Cereal Chemistry. 98(5):1112-1122. https://doi.org/10.1002/cche.10459.
Aoun, M., Carter, A., Thompson, Y.A., Ward, B.P., Morris, C.F. 2021. Environment characterization and genomic prediction for end-use quality traits in soft white winter wheat. The Plant Genome. 14(3). Article e20128. https://doi.org/10.1002/tpg2.20128.
Kiszonas, A.M., Ibba, M., Boehm Jr., J.D., Morris, C.F. 2021. Effects of the functional Gpc-B1 allele on soft durum wheat grain, milling, flour, dough, and breadmaking quality. Cereal Chemistry. 98(6):1250-1258. https://doi.org/10.1002/cche.10477.
Daba, S.D., McGee, R.J., Morris, C.F. 2022. Trait associations and genetic variability in field pea (Pisum sativum L.): Implications in variety development process. Cereal Chemistry. 99(2):355-367. https://doi.org/10.1002/cche.10496.
Kiszonas, A., Ibba, I.M., Boehm Jr., J.D., Morris, C.F. 2021. Effects of Glu-D1 gene introgressions on soft white spring durum wheat (Triticum turgidum ssp. durum) quality. Cereal Chemistry. 98(5):1112-1122. https://doi.org/10.1002/cche.10459.
Sandhu, K.S., Aoun, M., Morris, C.F., Carter, A.H. 2021. Genomic selection for end-use quality and processing traits in soft white winter wheat breeding program with machine and deep learning models. Biology. 10(7). Article 689. https://doi.org/10.3390/biology10070689.
Lafiandra, D., Sestili, F., Sissons, M., Kiszonas, A., Morris, C.F. 2022. Increasing the versatility of durum wheat through modifications of protein and starch composition and grain hardness. Foods. 11(11). Article 1532. https://doi.org/10.3390/foods11111532.
