Research Project: Enhancement of Eastern U.S. Wheat Quality, Genetics and Marketability

Location: Corn, Soybean and Wheat Quality Research

2021 Annual Report

Objectives
Objective 1: Develop accurate and efficient testing methods for processing and marketing quality of soft winter (SW) wheat. Sub-objective 1a. Develop simple and fast methods for the estimation of wheat grain PHS. Sub-objective 1b. Improve the existing cracker baking test to make it easier and more widely useable. Objective 2: Identify SW wheat varieties with various quality characteristics for new food uses. Sub-objective 2a. Determine the suitability of eastern SW wheat for making tortillas and identify the required quality characteristics. Sub-objective 2b. Determine the suitability of eastern SW wheat for making white salted noodles and identify the required quality characteristics. Sub-objective 2c. Develop and evaluate partial and full waxy wheat germplasms for new use. Objective 3: Develop markers for pre-harvest sprouting using a diverse SW wheat population. Sub-objective 3a. Find Eastern SW wheat varieties closely related genetically that differ in PHS resistance. Sub-objective 3b. Locate regions for PHS resistance using a Genome-Wide Association Study (GWAS) on a diverse panel of SW wheat with genotype-by-sequencing (GBS) markers. Sub-objective 3c. Uncover genes differentially expressed under conditions conducive to PHS versus non-conducive comparing results between lines that are resistant or susceptible to PHS. Sub-objective 3d. Develop markers for resistance to PHS. Objective 4: Evaluate and report the milling (processing and intrinsic end-use quality) parameters of SW wheat commercially viable cultivars.

Approach
The Soft Wheat Quality Laboratory (SWQL) aims to improve the end-use quality, uses and marketability of soft winter (SW) wheat in the eastern U.S. by contributing to the development of wheat varieties of improved end-use quality potential and developing new food uses. To attain this goal, the SWQL works to develop reliable and efficient quality testing methods, performs fundamental research on grain characteristics and genetics associated with quality traits, explores potentials of eastern soft wheat for extended uses and performs the comprehensive evaluation of breeding lines for end use quality. The project plan encompasses the effective evaluation of pre-harvest sprouting (PHS) damage and cracker baking quality potential, extended use potentials for tortillas and noodles, genetic factors controlling PHS, and milling and baking quality evaluation of SW wheat, which are crucial for the quality improvement and extended uses of eastern SW wheat. The required quality characteristics and suitability of eastern SW wheat grain for making tortillas and soft-bite wheat salted noodles will be identified and demonstrated, respectively. Development of partial and full waxy wheat germplasms will be continued, and their potential uses including tortilla and noodles will be examined. The identification of genetic factors controlling PHS and development of markers for PHS resistance will be conducted in four phases: 1) identify eastern SW wheat varieties closely related genetically that differ in PHS resistance; 2) locate regions for PHS resistance using a Genome-Wide Association Study (GWAS) on a diverse panel of SW wheat with genotype-by-sequencing markers; 3) identify genes differentially expressed under conditions conducive to PHS versus non-conducive comparing results between lines that are resistant or susceptible to PHS; and 4) develop markers for PHS resistance from GWAS and expression analysis. To contribute to the development of wheat varieties of improved end-use quality potential, the annual evaluation of eastern SW wheat breeding lines for defined milling and baking quality characteristics wil be conducted in collaboration with eastern SW breeding programs.

Progress Report
This project aimed to improve the milling and baking quality of eastern soft wheat varieties by developing accurate and reliable quality testing methods, identifying the biochemical and genetic characteristics of wheat important for extended uses, and contributing to the development of wheat varieties by conducting the end-use quality evaluation of wheat breeding lines. Objective 1, develop accurate and efficient testing methods to determine the processing and marketing quality of soft winter (SW) wheat. Under the assumption that pre-harvest sprouting (PHS) damaged wheat grain releases a greater amount of minerals, sugars, protein, and soluble fibers than sound grain, which reduces the electrical resistance of the grain soaking water, wheat grain was soaked in distilled water, and the electrical resistance of the soaking water was determined using a portable electrical multi-meter as an estimate of PHS damage. The optimum grain weight, grain soaking time and electrical resistance reading time were determined for the electrical resistance test of wheat grain soaking water. The best differentiation of three soft wheat grain samples showing low, medium and high degrees of PHS was achieved with 2 g wheat grain soaked in 25 mL distilled water for 15 sec with vortex stirring, and electrical resistance was read 2 min after soaking. For a set of 15 samples with a wide range of PHS damage, the electrical resistance showed strong relationships with two conventional PHS tests, falling number and a-amylase activity, proving that the approach could be developed as a method to more simply and quickly assess wheat grain PHS than the falling number test. The current cracker baking test employs an uncommon, expensive piece of equipment that is not readily available, limiting its widespread adoption by the baking industry and wheat quality testing labs. A pasta dough sheeter attached to a tabletop dough mixer and a portable laboratory scale noodle maker were tested for their potential application in the preparation of cracker dough sheets (as a replacement for the current dough sheeter) using three soft winter wheat flours considerably different in the flour characteristics important for making crackers. The pasta sheeter produced a heavier dough sheet, which exhibited a smaller weight loss during baking, and consequently a heavier and larger cracker with a lower stack height and fewer blisters than the noodle maker and currently used dough sheeter. The pasta sheeter led to bigger differences in cracker stack height, but smaller differences in width and blister number, than the other two sheeters. The noodle maker produced bigger differences in cracker width and blister number than the other sheeters. Both the paster sheeter and noodle maker produced cracker dough sheets of comparable thickness to the currently used sheeter and effectively differentiated three flours with regards to their cracker quality parameters, indicating their potential as replacements for the current dough sheeter, which will be further examined using 15 wheat flours with widely different baking qualities in subsequent experiments. Objective 2, identify SW wheat varieties with various quality characteristics for new food uses. Thirty-nine eastern soft wheat (ESW) varieties were grown in 2020 to obtain the grains, and five commercial tortilla flours were obtained from milling companies in the U.S. and Mexico and used as the references. Wheat grains were analyzed for test weight, kernel hardness and protein content, and milled to flour using a pilot scale mill. To determine the tortilla-making potential of ESW varieties, both ESW and commercial tortilla flours were evaluated for comprehensive compositional and biochemical characteristics. The ESW varieties varied widely in both grain protein content and kernel hardness. Flour protein and damaged starch contents of ESW varieties ranged from 6.6 to 10.2% and 1.4 to 6.2%, respectively, and were lower or comparable to those of commercial tortilla flours. The protein strength of ESW varieties as determined by lactic acid solvent retention capacity and sodium dodecyl sulfate sedimentation volume tests was comparable to that of commercial tortilla flours with overlapping test values. Wheat grains of 25 eastern soft wheat (ESW) varieties grown in 2020 were obtained, and five commercial white salted noodle (WSN) flours from milling companies in Japan and Korea were used as the references. Wheat grains were analyzed for test weight, kernel hardness and protein content, and milled to flour using a pilot scale mill. To determine the WSN-making potential of ESW varieties, both ESW and commercial WSN flours were evaluated for comprehensive compositional and biochemical characteristics. ESW varieties exhibited typical grain protein contents and kernel hardness values ranging from 8.6 to 11.1% and 5.4 to 20.0, respectively, with no sign of pre-harvest sprouting damage. The flours milled from the 25 ESW varieties with a milling yield ranging from 66.1 to 73.8% showed a flour protein content and strength, ash content and damaged starch content comparable to or lower than those of commercial WSN flours. The ESW flours had a finer flour particle size with a lower proportion of coarse particles and a higher proportion of fine particles compared to commercial WSN flours. Twenty-eight additional partial-waxy lines were identified using marker-assisted selection. Three ESW breeding programs were provided with thirty-nine to forty-three waxy and partial waxy germplasms for the determination of their agronomic performance and grain yield potential. Forty-six to sixty waxy and partial waxy lines in each of three cultivar backgrounds were grown in the 2020/21 crop year and analyzed for grain and flour characteristics, starch amylose content and starch gelling and hot-paste properties. Ten waxy wheat lines of two soft red winter wheat cultivar backgrounds were released and their germplasm registrations were completed with a publication in the Journal of Plant Registrations. Five thousand seeds of each germplasm were deposited at the National Center for Genetic Resources Preservation. Objective 3, develop markers for pre-harvest sprouting using a diverse SW wheat population. For Objective 3a, we were to identify closely related soft winter wheat varieties with opposite pre-harvest sprouting resistance. We have identified four pairs, related genetically by >1,600 markers. One of the pairs had high alpha-amylase activity and a low falling number indicating susceptibility, and another pair had low alpha amylase activity and a high falling number indicating resistance. The alpha-amylase and falling number results were consistent over four years of data. For Objective 3b, we were to develop at least 1,000 markers for the association mapping population. We have developed 1,600 and plan to add additional markers, especially on the D genome which is underrepresented. For Objective 3c, we were to perform RNA sequencing on pairs of genetically similar SWW varieties as part of next year’s objective. Samples have been sent for sequencing and we await their return for on-time analysis next year. For Objective 3d, we were to develop markers using data from genome-wide association studies and expression analyses. While we have no goals currently due, we have performed a genome-wide association study on our current data set and have found several significant locations with agreement of at least three of six genome-wide association models. Objective 4, evaluate and report the milling (processing and intrinsic end-use quality) parameters of SW wheat commercially viable cultivars. The comprehensive milling and baking quality evaluations for 3,616 samples harvested in 2020 and submitted by eleven public and private eastern soft wheat breeding programs have been completed. The test results were summarized, analyzed, and shared with the breeding programs with suggestions, directly contributing to the development of new wheat varieties possessing superior quality. We coordinated the Soft Wheat Quality Council (SWQC) annual evaluation of new varieties and advanced breeding lines by managing the entry grow-outs in three locations, procuring wheat grain samples, carrying out pilot-scale milling, distributing flour samples to collaborators, performing quality trait evaluations, and preparing a report that collates quality evaluations among the collaborators for presentation at the annual SWQC Meeting. We participated in the Pacific Northwest Wheat Quality Project and Michigan State University Wheat Quality Testing Project and performed the comprehensive evaluation of nineteen advanced breeding lines and varieties for the former and eight for the latter for flour characteristics and baking quality.

Accomplishments
1. Gluten protein characteristics desirable for making baking powder biscuits. Baking powder biscuits are a type of quick bread commonly consumed in the United States and are prepared from soft wheat flour of intermediate-to-high protein content; however, little is known about the gluten protein strength and composition of U.S. eastern soft wheat (ESW) suitable for making biscuits, making the development and efficient selection of biscuit wheat varieties difficult. ARS scientists in Wooster, Ohio, identified the gluten protein composition, especially the high molecular weight glutenin subunit (HMW-GS) profiles and rye-origin protein types, of ESW varieties required for producing good-quality biscuits with a high height and large volume. Thirty-five ESW wheat varieties carrying thirteen predominant HMW-GS profiles and three different rye protein types were tested for flour protein characteristics and biscuit quality attributes including height, shape and volume to determine the influences of protein characteristics on biscuit quality parameters and identify the protein profiles ideal for biscuit baking. It was found that HMW-GSs and rye protein types differently influenced the overall gluten protein strength and biscuit quality, which are crucial for the selection of the appropriate parents for crossings and the screening of breeding lines in the development of biscuit wheat varieties with necessary protein characteristics. These results provide wheat breeders with an effective and efficient tool for identifying and eventually developing varieties designed for making biscuits by allowing them to use the HMW-GS genetic markers for the rapid and reliable selection of breeding lines and varieties possessing the appropriate protein content and strength for making biscuits. The obtained information has been shared with the scientific community via a presentation at an international meeting, and will be presented to the milling and baking industry and wheat breeders at the future annual stakeholders meeting and published in a refereed journal.

2. Release and registration of ten soft red winter waxy wheat germplasms. Wheat starch is composed of two different types of molecules, amylose and amylopectin, which are considerably different in size, structure, and properties. The proportion of these two molecules is the major determinant of starch functional properties and subsequently product quality including shape, texture, and self-life. The starch of normal wheat varieties is typically composed of 25% amylose and 75% amylopectin molecules, while the starch of waxy varieties is primarily composed of amylopectin molecules. Waxy wheat starch cooks at a lower temperature and absorbs more water faster when heated, produces thicker paste, forms a weaker gel, and retains water better than normal wheat starch, and is useful for extending the moistness of bread, improving textural properties and shortening the cooking time of white salted noodles (like udon-type noodles) when blended with normal wheat flour. For the first time, ARS scientists in Wooster, Ohio, released ten soft red winter (SRW) waxy wheat germplasms, which produce grain containing starch largely composed of amylopectin molecules, completed their registrations in the Journal of Plant Registrations, and deposited 5,000 seeds of each germplasm at the National Center for Genetic Resources Preservation. The ten waxy wheat germplasms were developed by the incorporation of null waxy genes into two SRW wheat cultivars, Kristy and Wilson, and have been shared with three wheat breeding programs for the evaluation of their agronomic performance, including grain yield and disease resistance, and eventual selection as varieties. The released waxy wheat germplasms would also serve as useful genetic resources of waxy starch characteristics in the development of waxy wheat varieties and, when further selected and released as varieties, would be uniquely fit for the products requiring such starch characteristics. They could also be used by millers and bakers as new and novel ingredients for product quality improvement and new uses.

Review Publications
Ma, F., Baik, B.V. 2021. Influences of grain and protein characteristics on in vitro protein digestibility of modern and ancient wheat species. Journal of the Science of Food and Agriculture. 101(12):4578-4584. https://doi.org/10.1002/jsfa.11100.
Lee, Y., Ma, F., Byars, J.A., Felker, F.C., Liu, S.X., Mosier, N.S., Lee, J., Kenar, J.A., Baik, B.V. 2021. Influences of hydrothermal and pressure treatments on compositional and hydration properties of wheat bran and dough mixing properties of whole wheat meal. Cereal Chemistry. 98(3):673-682. https://doi.org/10.1002/cche.10411.
Shiga, T.M., Yang, H., Penning, B., Olek, A., McCann, M.C., Carpita, N.C. 2021. A TEMPO-catalyzed oxidation-reduction method to probe surface and anhydrous crystalline-core domains of cellulose microfibril bundles. Cellulose. 28:5305-5319. https://doi.org/10.1007/s10570-021-03815-9.
Sim, E., Park, E., Ma, F., Baik, B.V., Fonseca, J.M., Delwiche, S.R. 2020. Sensory and physicochemical properties of whole wheat salted noodles under different preparations of bran. Journal of Cereal Science. 96(1):Article 103112. https://doi.org/10.1016/j.jcs.2020.103112.
Xu, M., Hou, G.G., Ma, F., Ding, J., Deng, L., Kahraman, O., Niu, M., Trivettea, K., Lee, B., Wu, L., Baik, B.V. 2020. Evaluation of aleurone flour on dough, textural, and nutritional properties of instant fried noodles. LWT - Food Science and Technology. 126: Article 109294. https://doi.org/10.1016/j.lwt.2020.109294.
Mergoum, M., Johnson, J.W., Buck, J.W., Sutton, S., Lopez, B., Bland, D., Chen, Z., Buntin, G.D., Mailhot, D.J., Babar, M.A., Mason, R.E., Harrison, S.A., Murphy, J., Ibrahim, A.M., Sutton, R.L., Simoneaux, B.E., Bockelman, H.E., Baik, B.V., Marshall, D.S., Cowger, C., Brown Guedira, G.L., Kolmer, J.A., Jin, Y., Cambron, S.E. 2021. A new soft red winter wheat cultivar, 'GA 07353-14E19', adapted to Georgia and the US Southeast environments. Journal of Plant Registrations. 15(2):337-344. https://doi.org/10.1002/plr2.20113.
Mergoum, M., Johnson, J.W., Sutton, S., Lopez, B., Bland, D., Chen, Z., Mailhot, D.J., Buck, J.W., Buntin, G.D., Babar, M.A., Mason, R.E., Harrison, S.A., Murphy, J.P., Ibrahim, A.M., Sutton, R., Simoneaux, B.E., Bockelman, H.E., Baik, B.V., Marshall, D.S., Cowger, C., Brown Guedira, G.L., Kolmer, J.A., Jin, Y., Cambron, S.E., Boyles, R. 2021. Soft red winter wheat, ‘GA 051207-14E53’: Adapted cultivar to Georgia and the USA southeast region. Journal of Plant Registrations. 15(1):132-139. https://doi.org/10.1002/plr2.20102.
Gill, K.S., Kumar, N., Carter, A.H., Randhawa, H.S., Morris, C.F., Baik, B.V., Higginbotham, R.W., Engle, D.A., Guy, S.O., Burke, I.C., Lyon, D., Murray, T.D., Chen, X. 2020. Registration of ‘Curiosity CL+' soft white winter wheat. Journal of Plant Registrations. 14(3):377-387. https://doi.org/10.1002/plr2.20066.
Gill, K.S., Kumar, N., Randhawa, H.S., Carter, A.H., Yenish, J., Morris, C.F., Baik, B.V., Higginbotham, R.W., Guy, S.O., Engle, D.A., Chen, X., Murray, T.D., Lyon, D. 2020. Registration of 'Mela CL+' soft white winter wheat. Journal of Plant Registrations. 14(2):144:152. https://doi.org/10.1002/plr2.20006.
Meier, N., Malla, S., Oakes, J.C., Murphy, J.P., Baik, B.V., Chao, S., Griffey, C.A. 2020. Registration of three soft red winter wheat germplasm lines with exceptional milling and cookie baking performance. Journal of Plant Registrations. 14(3):450-456. https://doi.org/10.1002/plr2.20055.
Griffey, C., Malla, S., Brooks, W., Seago, J., Christopher, A., Thomason, W., Pitman, R., Markham, R., Vaughn, M., Dunaway, D., Beahm, M., Barrack, C.L., Rucker, E., Behl, H., Hardiman, T., Beahm, B., Browning, P., Schmale Iii, D., Mcmaster, N., Curtis, J.T., Gulick, S., Ashburn, S.B., Jones Jr., N., Baik, B.V., Bockelman, H.E., Marshall, D.S., Fountain, M.O., Brown Guedira, G.L., Cowger, C., Cambron, S.E., Kolmer, J.A., Jin, Y., Chen, X., Garland Campbell, K.A., Sparry, E. 2020. Registration of ‘Hilliard’ wheat. Journal of Plant Registrations. 14(3):406-417. https://doi.org/10.1002/plr2.20073.
Pradhan, Sumit, Babar, M., Bai, G., Khan, J., Shahi, D., Avci, M., Guo, J., McBreen, J., Asseng, S., Gezan, S., Baik, B.V., Blount, A., Harrison, S. 2019. Genetic dissection of heat-responsive physiological traits to improve adaptation and increase yield potential in soft winter wheat. BMC Genomics. 66:941–950. https://doi.org/10.1007/s10722-019-00742-4.