Location: Wheat Health, Genetics, and Quality Research
2018 Annual Report
Objectives
The long-term objective of this project is to improve wheat quality, functionality and marketability in the Western U.S. Specifically, during the next five years we will focus on the following objectives:
Objective 1: Resolve the underlying genetics of end-use quality traits, and identify useful genetic variation to produce predictable and new end uses.
• Sub-objective 1A: Extend our understanding of the role(s) of kernel hardness and puroindoline genes in wheat grain quality and utilization.
• Sub-objective 1B: Extend our understanding of the role(s) of starch composition and waxy genes on wheat grain quality and utilization.
Objective 2: Increase the value and global competiveness of U.S. commercial wheat by enabling new technologies and methods to accurately assess end-use functionality; and to manipulate wheat fiber and antioxidant components to improve grain and flour quality.
• Sub-objective 2A: Develop a model system for identifying putative grain flavor loci/genes in wheat.
• Sub-objective 2B: Manipulate grain arabinoxylan content to improve flour quality, nutrition and utilization.
Objective 3: Congressionally designated as a direct mission of service, and non-hypothesis driven, the USDA-ARS Western Wheat Quality Laboratory will identify, evaluate, and screen the intrinsic end-use quality to enhance cultivar development.
Approach
Objective 1A: Puroindoline a, b, and Grain softness protein-1 genes are amplified from genomic DNA via PCR and sequenced, followed by alignments and phylogenetic analyses. Aegilops tauschii accessions are obtained from germplasm banks. Unique haplotypes are identified in synthetic hexaploid wheats and evaluated for kernel texture. Soft durum lines derived from Soft Svevo will be increased and receive complete milling and baking analyses. Kernel texture variation in the RIL population derived from Butte 86 x ND2603 will be mapped. Kernel texture variation referred to as “Super-Soft” will be mapped using an Alpowa Super-Soft derivative. RILs will be developed using single seed descent. Contingencies: Marker density will need to be sufficient to detect linkage disequilibrium. If a particular chromosome or arm has low polymorphsism, then additional markers will be added.
Objective 1B: Full waxy and partial waxy lines will be developed in Stephens, Xerpha, and MDM varieties. Waxy progeny are identified with I2/KI. Partial waxy lines are identified using PCR markers. NILs will be developed in a BC7F2 population using marker assisted selection. The 4A-null lines will be evaluated for Japanese Udon noodle. Full waxy lines will be evaluated in twin barrel extrusion.
Objective 2a: A system that uses a common check variety will be developed. Hollis (yummy) and ID703 (yucky) were used to make a DH mapping population. DH line vs. check t-values will be used as the phenotypes for mapping. Mapping will be employed to identify candidate genes/QTLs for consumption preference. Contingencies: Different ‘check’ varieties may be needed depending on the relative preference/avoidance. If the QTLs from one check variety do not fully agree with the QTLs from the second check variety, then a third intermediate preference variety will be evaluated. If LOD scores are not sufficiently large, then a sub-set of lines with contrasting consumption preference will be evaluated with a larger number of mice.
Objective 2b: Yumai 34 and Alpowa have high arabinoxylan (AX) content, whereas Louise has low levels. DH populations from Yumai 34 x Louise, Yumai 34 x Alpowa, and Alpowa x Yumai 34 were produced. These populations will be milled and baked, and evaluated by Solvent Retention Profiles and Bostwick viscosity. Total AX, water extractable AX (WE-AX), and arabinose to xylose ratio will be analyzed via GC-FID. All the DH lines will be genotyped with markers. Lines with contrasting high and low AX contents, high and low ratios of WE-AX vs. water unextractable, and high and low ratios of arabinose substitution will be identified. These traits will be compared with end-use quality phenotypes and will be analyzed via molecular markers. Contingencies: We will identify the ‘best’ choices for full AX analyses based on contrasting end-use quality traits. If there is not a ‘consensus’ among traits, then contrasting phenotypes will be selected for individual traits.
Objective 3: Testing and evaluation of experimental wheat breeding germplasm follows standard testing protocols, including Approved Methods of AACCI and AOAC. Tests include grain, milling, flour and end-products tests.
Progress Report
This report covers months 30-41 of the 5-year Project. Progress was made on all three objectives and their sub-ojectives, all of which fall under National Program 306, and contributes directly to the accomplishment of ARS Strategic Plan Goal 1 (Nutrition, Food Safety, and Quality), Performance measure 1.1.3 (Develop methods and technologies to better define, measure, preserve or enhance quality and improve utilization of food crops, animals and agricultural fibers). This research also addresses several problem areas, products, and outcomes identified in the NP 306 Action Plan, namely; Component 1 (Foods) Problem 1.A (Define, measure, and preserve/enhance/reduce attributes that impact quality and marketability).
Specific contributions were made by performing the sequence analysis and phylogenetic analysis of genes involved in wheat grain hardness and completing studies on soft kernel durum wheat milling and baking quality. Further, a study was completed on identifying additional quantitative trait loci (QTLs) responsible in hard red spring wheat for kernel texture. Germplasm for the analysis of a unique ‘Super Soft’ kernel trait was developed. Both spring and winter waxy wheat germplasm were developed and evaluated for agronomic, milling and baking quality. Lastly, we responded to a crisis involving low Falling Number by evaluating commercial enzyme-linked immunosorbent assay (ELISA) kits for alpha-amylase and performed a study on the relationship between Falling Number and soft wheat quality.
Accomplishments
1. The reason soft kernel durum is soft. Durum wheat normally has extremely hard kernels. The invention of soft kernel durum has the potential to revolutionize durum wheat utilization and production, however; the genetic basis for the soft kernel trait has not been fully understood. An ARS scientist in Pullman, Washington, in cooperation with a Washington State University researcher, and one with North Dakota State University, Fargo, North Dakota, have identified that a very small tip of a chromosome from bread wheat was transferred to durum wheat, potentially correlating to soft kernel. This discovery will help guide the development and breeding of new, improved soft kernel durum wheat varieties.
2. Milling and baking quality of U.S. soft white wheat. A more thorough understanding of the underlying genetics of soft white wheat quality will aid the development of new varieties. ARS scientists in Pullman, Washington, in cooperation with Washington State University researchers, have identified additional genetic determinants of the milling, flour performance, and baking quality of soft white wheat. These determinants can be used to select for better and more specific end-use quality. This more in-depth understanding of the genetic factors impacting milling and baking quality will enable breeders to more effectively discard poor quality germplasm while retaining superior material, thus saving time and resources.
3. Grain hardness of U.S. hard red spring wheat. Grain hardness (kernel texture) is a key factor controlling milling, flour performance and baking quality. Yet, variation in grain hardness is not fully understood. ARS scientists in Pullman, Washington, in cooperation with Washington State University researchers, have identified genetic factors that contribute to overall variation in grain hardness. These identified genetic factors can be used to breed higher quality hard red spring wheat varieties.
4. Testing commercial kits for detecting an enzyme related to wheat grain quality. The enzyme alpha-amylase decreases quality when present in flour, and affects farmers, millers and bakers. Although there are various means to measure amylase, all have limitations. ARS scientists in Pullman, Washington, have evaluated three off-the-shelf commercial enzyme detection kits, and found that one was effective in accurately measuring amylase in wheat grain. This research demonstrates one possible, accurate means of measuring this quality-degrading enzyme in wheat. Accurate detection is an important step in controlling wheat grain quality.
5. A historical review of breeding wheat for quality. One important aspect of breeding new wheat varieties is ensuring that they have superior end-use quality. A concise summary of the techniques and history of wheat improvement provides a valuable resource for students and scientists. ARS scientists in Pullman, Washington, have produced a historical review of the methods used to breed new wheat varieties with superior quality. The authors conclude that certain types of new technologies may provide significant advances but must be applied in specific, effective ways.
6. Wheat bran may mitigate child malnutrition. One aspect of child malnutrition is pathogen-related diarrhea. Wheat bran with its high content of dietary fiber may contribute to a healthier microbiome in the gut. An ARS scientist in Pullman, Washington, found that in a laboratory model system, wheat bran provided positive effects on four health-related traits. If the model results prove applicable, wheat bran could play a role in mitigating the damaging effects of malnutrition and pathogens on the intestines.
7. Proteins that interact with gluten. Puroindolines are two endogenous proteins that cause wheat grain to be soft. It is not known if or how they may interact with gluten proteins. An ARS scientist in Pullman, Washington, in cooperation with researchers at the University of Minnesota, Italy and Ghana, has determined that puroindolines altered the structure of gluten proteins. These structural modifications were observed using various analytical methods and may occur prior to dough mixing. The results provide greater insight into how various factors contribute to flour and baking quality.
Review Publications
Jernigan, K.L., Godoy, J.G., Huang, M., Zhou, Y., Morris, C.F., Garland Campbell, K.A., Zhang, Z., Carter, A.H. 2018. Genetic dissection of end-use quality traits in adapted soft white winter wheat. Frontiers in Plant Science. https://www.frontiersin.org/articles/10.3389/fpls.2018.00271/full.
Quayson, E.T., Marti, A., Morris, C.F., Marengo, M., Bonomi, F., Seetharaman, K., Iametti, S. 2018. Structural consequences of the interaction of puroindolines with gluten proteins. Food Chemistry. 253:255-261.
Boehm, J.D., Ibba, M., Kiszonas, A., See, D.R., Skinner, D.Z., Morris, C.F. 2018. Genetic analysis of kernel texture (grain hardness) in a hard red spring wheat (Triticum aestivum L.) bi-parental population. Journal of Cereal Science. 79:57-65.
Kiszonas, A., Morris, C.F. 2018. Wheat breeding for quality: An historical review. Cereal Chemistry. 95:17–34.
Kiszonas, A. 2017. Can wheat bran mitigate malnutrition and enteric pathogens? Cereal Foods World. 62:214-217.
Kiszonas, A., Morris, C.F. 2018. Evaluation of commercial a-amylase enzyme-linked immunosorbent assay (ELISA) test kits for wheat. Cereal Chemistry. 95:206-210.
Boehm, J.D., Zhang, M., Xiwen, C., Morris, C.F. 2017. Molecular and cytogenetic characterization of the 5DS-5BS chromosome translocation conditioning soft kernel texture in durum wheat. The Plant Genome. 10:1-11.
Kiszonas, A., Engle, D.A., Pierantoni Arroyo, L.A., Morris, C.F. 2018. Relationships between falling number, a-amylase activity, milling, and sponge cake quality of soft white wheat. Cereal Chemistry. 95:373-385.
Murray, J.C., Kiszonas, A., Morris, C.F. 2017. Pasta production: complexity in defining processing conditions for reference trials and quality assessment models. Cereal Chemistry. 94:791-797.
Ibba, M., Kiszonas, A., Morris, C.F. 2018. Development of haplotype-specific molecular markers for the low-molecular-weight glutenin subunits. Molecular Breeding. 38:68. https://doi.org/10.1007/s11032-018-0827-9.
Itria, M., Kiszonas, A., Morris, C.F. 2017. Influence of low-molecular-weight glutenin subunit haplotypes on dough rheology in elite common wheat varieties. Cereal Chemistry. 94:1016-1027.
Boehm, J.D., Ibba, M., Kiszonas, A., See, D.R., Skinner, D.Z., Morris, C.F. 2017. Identification of genotyping-by-sequencing sequence tags associated with milling performance and end-use quality traits in hard red spring wheat (Triticum aestivum L.). Journal of Cereal Science. 77:73-83.
