Location: Corn, Soybean and Wheat Quality Research
2023 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 and uses of eastern soft wheat varieties by developing accurate and reliable quality testing methods, identifying the associated biochemical and genetic characteristics, developing germplasms carrying unique functional and agronomic traits, 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 eastern U.S. soft winter (ESW) wheat. Our research continued to develop simple and fast methods for the estimation of wheat grain pre-harvest sprouting (PHS) (Sub-objective 1a). The electrical conductivity of wheat grain soaking water and hot-paste flow distance were further tested using 198 wheat grain samples with varying degrees of PHS to validate their reliability in estimating falling number (FN), which is the industry standard but has a low throughput. PHS increases the soluble solid content of grain soaking water, and these solids act as electrolytes to increase electrical conductivity. Increased alpha-amylase activity of sprouted wheat grain lowers the hot-paste fluidity/viscosity, consequently increasing its flow distance. The 198 ESW wheat varieties were grown and subjected to sprouting conditions in Wooster, Ohio, to obtain wheat grains of varying PHS for validation of the electrical conductivity and hot-paste flow distance tests. The electrical resistance of grain soaking water approximated FN with 51% predictability, whereas the hot-paste flow distance of whole grain meals approximated FN with 84% predictability. The results prove that: 1) the electrical conductivity of grain soaking water, although it is easy and fast to run, falls short of providing a reliable estimation of FN; and 2) the hot-paste flow distance of whole grain meals provides a satisfactory estimation of FN and is simpler, easier, and faster to run than the FN test.
We continued to improve the cracker baking test to make it easier and more widely useable (Sub-objective 1b). In furtherance of the previous accomplishments: 1) successful use of a pasta dough sheeter and a noodle maker to replace the heavy and not commonly available dough sheeter; and 2) determination of optimal water amount for the preparation of cracker dough, an additional improvement of the cracker baking test was accomplished by identifying and successfully adopting a press device, which allows the efficient, even and clear cutting and docking of the cracker dough sheet before baking. The employment of the device lowered variations in length, width and thickness of crackers prepared from the same batch of dough, contributing to the increased repeatability of the cracker baking test.
Objective 2, identify ESW wheat varieties with various quality characteristics for new food uses. We determined the quality attributes of tortillas in continuation of determining the suitability of ESW wheat for making tortillas and identifying the required quality characteristics (Sub-objective 2a). Tortilla diameter, opacity, and rollability of 25 ESW wheat flours were determined and compared to those of commercial tortilla flours (CTFs). ESW wheat flours with a lower damaged starch content and polyphenol oxidase activity than CTFs produced tortillas of larger diameter and brighter color than the latter. Seven ESW wheat flours with strong gluten protein were identified to produce tortillas of comparable quality to those prepared from CTFs in diameter, opacity score and rollability score. Lactic acid solvent retention capacity, a measure of protein strength, effectively estimated the tortilla making quality of ESW wheat flour. The results provide guidance for selecting ESW wheat varieties for making tortillas and prove that ESW wheat flours of strong gluten strength can be successfully used for making tortillas.
White salted noodles (WSN) were prepared from 25 ESW wheat varieties of varying protein characteristics and their quality attributes were determined (Sub-objective 2b) to further identify characteristics desirable for making WSN in comparison to those made from commercial flours. ESW wheat flours exhibited large differences in cooking loss and textural properties of cooked noodles, which was expected from the large variations in their physical and compositional characteristics. The thickness, length, and color of the noodle dough sheet of ESW wheat flours, as well as the cooking loss and textural properties of cooked noodles, overlapped those of commercial noodle flours, indicating that selected ESW wheat flours can be successfully used for making WSN. Twelve out of twenty-five ESW wheat flours similar in protein content and strength to commercial flours produced WSN of comparable color, cooking loss and textural properties of cooked noodles. Those ESW wheat flours, however, produced WSN lower in cohesiveness than commercial flours, likely due to the lack of starch of reduced amylose content. The grain and flour characteristics of ESW wheat varieties and WSN quality attributes will be analyzed and compared to those of commercial noodle flours to develop a quality profile of ESW wheat for making WSN.
We determined the pasting properties and starch amylose content of the partial and full waxy lines in continuation of their development and evaluation for new use (Sub-objective 2c). Starches were isolated from 26 partial waxy and 10 full waxy wheat lines of three cultivar backgrounds along with their parents and their amylose contents and pasting properties were determined to identify their potential uses. The parents with no waxy trait showed an amylose content ranging from 26.5 to 27.1%, while the amylose content of full waxy lines ranged from 2.0 to 7.2%. The amylose contents of single-null and double-null partial waxy lines, which carry one or two inactive amylose synthesis governing genes, were 24.3-27.1% and 17.3-25.1%, respectively. With a decreased starch amylose content, partial waxy and full waxy lines showed starch pasting properties distinctly different from their parents. Full waxy wheat lines had much higher starch paste viscosities at much lower temperatures than the parents. Starch pasting peak viscosities and temperatures of full waxy wheat lines were higher by 8.5-49.8 units and lower by 20 degrees C than those of the parents, respectively. The starch pasting peak viscosities and temperatures of partial waxy wheat lines were intermediate between full waxy lines and parents, but closer to the latter. With their unique functional properties of starch, partial and full waxy wheat lines would bring additional opportunities to ESW wheat for extended uses with improved product quality.
Objective 3, Develop markers for pre-harvest sprouting using a diverse ESW wheat population. Gene expression in pairs of genetically similar soft winter wheat cultivars that differ in pre-harvest sprouting resistance was studied. The resistant cultivar had an average falling number of 311 (acceptable as sound grain) under natural rain events. The susceptible cultivar had an average falling number of 106 (well below the threshold of acceptance by grain elevators). Forty-eight genes were discovered as potentially involved in pre-harvest sprouting. A gene was discovered that appears to regulate the expression of a major gene known to affect pre-harvest sprouting resistance. This work increases understanding of pre-harvest sprouting resistance gene regulation. This research can be used by the ARS lab in Wooster, Ohio, and other scientists to improve pre-harvest sprouting resistance in soft winter wheat. Marker development for this new pre-harvest sprouting resistance gene is underway. When completed, it will be used by wheat breeders to improve pre-harvest sprouting resistance. A genome-wide association study with 188 diverse soft winter wheat cultivars has been published. It details eleven chromosome locations for pre-harvest sprouting resistance that explain most of the variation under natural rain events in the tested wheat population. One chromosome location explains 40% and two others explain 17% each. Other locations had smaller effects. Only one chromosome location explaining minor variation in pre-harvest sprouting overlapped with an agronomic trait (heading date), and none overlapped with flour quality traits. Markers are associated with these 11 pre-harvest sprouting resistance chromosome locations; thus, breeders can use them to improve pre-harvest sprouting resistance with minimal impact on flour quality or the agronomic traits of wheat.
Objective 4, evaluate and report the milling parameters of commercially viable ESW wheat cultivars. The comprehensive milling and baking quality evaluations for 3,259 samples harvested in 2022 that were submitted by nine public and private eastern soft wheat breeding programs, five uniform regional performance trials, five state variety performance trials and one research collaborator 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) Project for the annual evaluation of new varieties and advanced breeding lines by organizing the entry grow-out locations, carrying out pilot-scale milling, distributing flour samples to collaborators, performing quality trait evaluations, assembling and analyzing the data, 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 advanced breeding lines and varieties for flour characteristics and baking quality.
Accomplishments
1. Partial-waxy wheat lines carrying unique starch properties introduced into eastern soft winter wheat cultivars. Partial waxy wheat carrying one or two inactive genes governing the synthesis of amylose (one of the two types of starch molecules) yields grain with a reduced starch amylose content, which is known to improve the cooking and textural properties and sensory acceptance of Asian noodles. It also better maintains moistness of baked wheat products, extending the shelf life. Partial waxy wheat varieties are available in soft white, hard white and hard red wheat classes, but not in eastern U.S. soft winter (ESW) wheat. ARS researchers in Wooster, Ohio, developed 12 partial waxy wheat lines by the introduction of inactive amylose synthesis genes into two ESW wheat cultivars and released them. Both single-null (one inactive gene) and double-null (two inactive genes) partial waxy wheat lines were not different from the parents of all active amylose synthesis genes in grain protein content and kernel hardness, but were significantly lower in starch amylose content than the parents. Single-null and double-null partial waxy wheat lines exhibited 2.3-2.8% and 4.1-5.7% lower starch amylose contents, respectively, than the parents, which makes their starch functionalities desirable for the improved cooking and textural properties of noodles and related food products. The released 12 partial waxy ESW wheat lines could be further screened for agronomic performance and used by wheat breeders as the genetic resources of unique starch characteristics for incorporation into the elite ESW wheat varieties, which will increase extended use potential and marketability.
2. Quality profiles of eastern soft winter (ESW) wheat for making soft-bite white salted noodles (WSN) established. With low-to-intermediate protein content, weak-to-strong gluten strength and low damaged starch content, selected ESW wheat could potentially be used to make noodles of desirable quality, which presents an unexplored opportunity for increased use and marketability. However, the suitability of ESW wheat for making WSN has yet to be substantiated and the quality characteristics required for making noodles still need to be identified and cataloged. ARS researchers in Wooster, Ohio, found that ESW wheat relatively low in kernel hardness and high in protein content and strength, produced WSN of comparable cooking and textural properties to those prepared from commercial noodle flours of premium quality. The low damaged starch content of ESW wheat flour was identified to be an advantage in the production of cooked noodles with reduced stickiness. The findings increase opportunities for expanding the use and marketing of ESW wheat for making noodles and provide millers and noodle manufacturers with guidance in the selection of ESW wheat grain and flour suitable for noodle production, and breeders with the screening tools to develop ESW wheat varieties suitable for making noodles.
3. Identification of high molecular weight glutenin subunit (HMW-GS) profiles of eastern U.S. soft winter (ESW) wheat appropriate for making soft-bite white salted noodles (WSN). The HMW-GS composition of wheat has a dominant influence on gluten strength and product quality. The flour protein content and gluten strength required for making WSN are well established, whereas the HMW-GS composition of ESW wheat desirable for making WSN and its association with WSN quality attributes are poorly understood. ARS researchers in Wooster, Ohio, identified the HMW-GSs of ESW wheat desirable for the production of WSN and established their profiles. ESW wheat varieties carrying one pair of HMW-GSs associated with the weakest gluten strength produced WSN with a higher cooking loss and lower textural quality compared to those carrying other HMW-GSs, and ESW wheat varieties carrying translocated rye genes (1BL/1RS) produced noodles of undesirably high stickiness. ESW wheat varieties carrying one of three HMW-GS profiles associated with strong gluten strength, and no translocated rye genes of the 1BL/1RS type, possess gluten characteristics associated with reduced cooking loss, reduced cooked noodle stickiness and improved cooked noodle textural properties, and thus are expected to produce WSN most comparable to those prepared from commercial noodle flours. The HMW-GS profiles will be an effective tool for the identification of ESW wheat breeding lines or varieties possessing protein characteristics suitable for making WSN, helping wheat breeders with the genetic improvement of ESW wheat and wheat millers with the procurement of desired quality wheat grain.
4. Eleven new winter wheat chromosome locations for pre-harvest sprouting resistance discovered. The value of the winter wheat crop in the U.S. last year was ~$2.3 billion. Pre-harvest sprouting damage can reduce the soft winter wheat crop value by up to 30% in the U.S. and is a growing problem in the rest of the world due to climate change. Ideally, when improving wheat resistance to pre-harvest sprouting other important characteristics, such as agronomic traits and milling and baking quality should remain unchanged or improved to encourage adoption of the variety by farmers and acceptance for use in baked goods. ARS researchers in Wooster, Ohio, conducted a genome-wide association study to find chromosome locations for pre-harvest sprouting resistance, milling and baking quality, and agronomic traits in 188 soft winter wheat breeding lines representing most of the soft winter wheat diversity in the eastern U.S. To find significant locations for all traits across 21 chromosomes, 1,978 markers were used in the analysis. The researchers found eleven chromosome locations explaining most of the variation in pre-harvest sprouting resistance under natural rain events in the tested wheat population, with one chromosome location explaining ~40% and two others explaining ~17% each. These chromosome locations have well-characterized markers that wheat breeders can use to develop new varieties that reduce pre-harvest sprouting damage without affecting milling and baking quality or agronomic traits.
5. Forty-seven new pre-harvest sprouting resistance genes of wheat identified by expression analysis. Ideally, all genes involved in pre-harvest sprouting resistance would be known to produce new wheat varieties that avoid significant losses for farmers and poor-quality baked goods. Only ten genes involved in pre-harvest sprouting have been characterized. ARS researchers in Wooster, Ohio, identified and described forty-eight genes, one previously known, involved in pre-harvest sprouting, using RNA sequencing to observe gene expression over the entire genome. Expression in a cultivar that was susceptible to pre-harvest sprouting was compared to one that was resistant at different seed development times. The resistant cultivar had an average falling number of 311 (acceptable as sound grain) under natural rain events. The susceptible cultivar had an average falling number of 106 (well below the threshold of acceptance by grain elevators). A gene that can regulate a previously known major pre-harvest sprouting resistant gene was discovered. This gene reduces the expression of the previously known gene by 50%. By combining the “best” versions of these genes in terms of their expression, stronger pre-harvest spouting resistance may be possible. All forty-eight genes improve scientists’ understanding of the pre-harvest sprouting resistance gene network and the entire pre-harvest sprouting process as it occurs. The new genes that have a direct effect on pre-harvest spouting resistance can be developed as resistance markers for breeders to improve wheat varieties. New varieties should reduce the losses of farmers due to pre-harvest sprouting damage and improve the quality of baked goods for consumers and the baking industry.
Review Publications
Ma, F., Brown Guedira, G.L., Kang, M., Baik, B.V. 2022. Allelic variations in phenology genes of eastern U.S. soft winter and Korean winter wheat and their associations with heading date. Plants. 11(22). Article #3116. https://doi.org/10.3390/plants11223116.
Ma, F., Baik, B.V. 2022. Grain and flour characteristics of eastern U.S. soft winter wheat desirable for making soft-bite white salted noodles. Cereal Chemistry. 100(2):445-459. https://doi.org/10.1002/cche.10625.
Penning, B. 2023. Gene expression differences related to pre-harvest sprouting uncovered in related wheat varieties by RNAseq analysis. Plant Gene. 33. Article #100404. https://doi.org/10.1016/j.plgene.2023.100404.
Lopez, S.R., Wiersma, A.T., Strauss, N.M., Watkins, T., Baik, B.V., Zhang, G., Sehgal, S.K., Kolb, F.L., Poland, J.A., Mason, R.E., Carter, A.H., Olson, E.L. 2023. Description of U6719-004 wheat germplasm with YrAS2388R stripe rust resistance introgression from Aegilops tauschii. Journal of Plant Registrations. 17(1):26-33. https://doi.org/10.1002/plr2.20226.
Moraes, W.B., Baik, B.V., Madden, L.V., Paul, P.A. 2023. Environmental conditions after fusarium head blight visual symptom development affect contamination of wheat grain with deoxynivalenol and deoxynivalenol-3- glucoside. Phytopathology. 113(2): 206-224. https://doi.org/10.1094/phyto-06-22-0199-r.
Patwa, N., Penning, B. 2023. Genetics of a diverse soft winter wheat population for pre-harvest sprouting, agronomic, and flour quality traits. Frontiers in Plant Science. 14. Article #1137808. https://doi.org/10.3389/fpls.2023.1137808.
Van Sanford, D., Clark, A.J., Bradley, C.A., Brown Guedira, G.L., Cowger, C., Dong, Y., Baik, B.V. 2023. Registration of ‘Pembroke 2021’ soft red winter wheat. Journal of Plant Registrations. 17:376-384. https://doi.org/10.1002/plr2.20271.
