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United States Department of Agriculture

Agricultural Research Service


Location: Wheat Genetics, Quality Physiology and Disease Research

2009 Annual Report

1a.Objectives (from AD-416)
Genetically improve wheat and other cereals for endosperm texture, Asian noodle color, carbohydrate composition, and develop new methods to evaluate end-product quality. Define genetic basis of desirable quality of Asian foods. Facilitate research on improving western wheats for domestic and Asian food product quality.

1b.Approach (from AD-416)
Determine the molecular and genetic basis of wheat grain texture by assessing puroindoline gene structure. Determine the effect of two different hardness alleles on grain texture, milling performance and baking quality. Assess the molecular genetic basis of discoloration in Asian noodles by identifying and characterizing polyphenoloxidase from wheat. Develop or adapt methods to evaluate wheat end-use quality with an emphasis on early generation testing. Employ gene expression measurement technology to identify genes contributing to desirable Asian food characteristics.

3.Progress Report
Considerable progress has been accomplished on identifying the genes, mechanisms and constituents of end-product quality of wheat grain. These include greater elucidation on dietary fiber, product darkening, the variety and environmental effects of wheat grain mineral content, the effects of different grain hardness genes in wheat and barley, the use of DNA markers for wheat improvement, laboratory methods related to cookie baking and flour quality. A book chapter was written on methodology used for assessing end-use quality in wheat. We determined that it is possible to manipulate mineral content of wheat grain using contemporary adapted germplasm. We determined that wheat grain ash is more greatly influenced by crop year and location than by variety though enough variation exists that the potential to manipulate ash content through plant breeding is plausible. Genetic analysis of wheat and its relatives would greatly advance the understanding of molecular mechanisms of grain discoloration in foods. We examined six wheat relative species. Seven new gene types were identified from these species and given designation. The development of high quality wheat varieties depends on a thorough understanding of the constituents of grain, and their variation due to genetics and environment. Certain carbohydrates are key constituents of wheat grain and have broad and far-reaching influences on milling and baking quality. Yet, variation in these constituents due to variety and environment are not fully understood. We analyzed fractions of carbohydrates in fifty-one hard winter and spring wheat varieties developed from eight public and private breeding programs in the U.S. Pacific Northwest. Winter and spring varieties were grown in three environments each. Grain hardness in common wheat is one of the most important parameters affecting milling and end-use qualities. Common wheat is classified and traded as either hard or soft based on endosperm texture. Soft-textured wheat typically has increased break flour yield, a smaller flour particle size, and less starch damage compared with hard-textured wheat. Therefore, flours from hard wheat are usually used for making bread, while flours from soft wheat are more suitable for producing biscuits, cookies and cakes. China is the largest producer and consumer of wheat in the world, where noodles are the most widely consumed wheat products in China, representing about 40% of national wheat consumption. We found that Chinese white noodles quality attributes were related to grain hardness, protein quality, flour whiteness, and starch properties. Therefore, genetic improvement of grain hardness is an important breeding objective for Chinese noodle quality.

1. Dietary fiber in wheat grain. Differences in dietary fiber levels in wheat grain are not well known. ARS researchers at the Western Wheat Quality Lab in Pullman, Washington, in cooperation with collaborators determined how dietary fiber levels vary among a collection of different varieties and grown in different locations. Different wheat varieties differed significantly due to genetics. The nutritional quality of wheat grain can be increased by genetically increasing the content of dietary fiber.

2. Noodle dough discoloration in wheat and wheat relatives. An undesirable brown color appears in Asian noodles and certain other wheat products due to an enzyme known as “Polyphenol Oxidase (PPO)”. ARS researchers at the Western Wheat Quality Lab in Pullman, Washington, in cooperation with collaborators characterized the PPO genes in wheat and wheat relatives. Further knowledge of the origins of PPO and the levels of PPO that occur in various wheat relatives was gained, showing that high PPO activity is likely caused by only a small number of the many PPO genes that are found in wheat. Future research can now be more efficiently focused on a few candidate genes.

3. Genes controlling barley grain hardness. The hardness of cereal grains, including barley, has a tremendous impact upon their suitability for various end-uses. ARS researchers at the Western Wheat Quality Lab in Pullman, Washington, in cooperation with collaborators identified the genes controlling endosperm texture in barley. These genes were found to vary greatly among varieties from diverse locations. Using these new genes, further modification of barley endosperm texture may be possible, which is believed to be advantageous to improving barley for end uses such as improved feed quality.

4. Development of new wheat varieties using special genetic techniques. Development of new wheat varieties requires efficient combining of genes from each parent. ARS researchers at the Western Wheat Quality Lab in Pullman, Washington, in cooperation with collaborators applied special genetic techniques to track parental genes. We demonstrated that these techniques provide a more efficient means to combine favorable genes from each parent. Application of the techniques will improve and speed the development of new wheat varieties.

5. Mineral content of wheat grain. Differences in the mineral content of wheat grain are not well known and affect milling and human health. ARS researchers at the Western Wheat Quality Lab in Pullman, Washington, in cooperation with collaborators determined how mineral content varies within a collection of different varieties grown in multiple locations. The mineral content of wheat grain was found to mostly be determined by where wheat is grown with smaller differences amongst varieties. The research indicates little ability to manipulate grain mineral content via breeding and genetics.

6. Effect of added proteins on noodle making. Certain genes control most of the variation in wheat grain texture, which in turn affects milling characteristics as well as end product quality. ARS researchers at the Western Wheat Quality Lab in Pullman, Washington, in cooperation with collaborators examined the color and texture characteristics of white salted noodles processed from flour made from a wheat variety containing additional levels of proteins. In general, the flours performed equally well. This shows that even high levels of certain proteins can be added to noodle doughs without detrimental effects on product quality.

7. Quality of wheat grain depends on kernel hardness. There are different genetic ways to make wheat kernels hard, but we don’t know which specific gene produce the best quality. ARS researchers at the Western Wheat Quality Lab in Pullman, Washington, in cooperation with collaborators studied a number of these different genes and how they affected Chinese noodle quality. Specific genes were shown to produce better flour milling performance and Chinese noodle quality. Plant breeders can incorporate the better genes into new wheat varieties to improve quality.

8. Color of wheat foods. Certain genes in wheat produce enzymes that discolor wheat foods, but the variety of genes is not fully understood. Such color changes affect the perceived quality and the product. ARS researchers at the Western Wheat Quality Lab in Pullman, Washington, in cooperation with collaborators identified discoloration enzymes in wheat and some of its relatives. Knowledge of these genes will allow plant breeders to develop new wheat varieties that produce grain with reduced discoloration problems.

9. Baking quality of cookie flour. Defining the potential cookie baking quality of flour is crucial to both wheat variety development programs, and to the baking industry where flour must be evaluated so that process parameters can be adjusted to successfully and economically produce baked products. ARS researchers at the Western Wheat Quality Lab in Pullman, Washington, in cooperation with 12 international collaborators evaluated a cookie bake test method. The new method was found to be a substantial improvement over the method it replaced. This new method will assist wheat breeders, cereal chemists and others tasked with accurately evaluating the baking quality of cookie flours.

10. More accurate assessment of flour quality. Occasionally, methods contain errors that have become entrenched over the years. Researchers at the Western Wheat Quality Lab in Pullman, Washington, in cooperation with collaborators identified an error in the “Solvent Retention Capacity (SRC)” method that is used extensively in both variety development work and in industry to define the potential utility of flour in baking. The Official method was corrected and communicated to users, and the implications of the correction were also evaluated. The corrected method will allow more accurate and reliable assessment of flour quality.

5.Significant Activities that Support Special Target Populations
SCEP employee/student at Washington State University is enrolled in the organic ag/sustainable agriculture program.

6.Technology Transfer

Number of Active CRADAs1
Number of the New/Active MTAs (providing only)1
Number of Invention Disclosures Submitted1

Review Publications
Li, S., Morris, C.F., Bettge, A.D. 2009. Genotype and environment variation for arabinoxylans in hard winter and spring wheats of the U.S. Pacific Northwest. Cereal Chemistry 86:88-95.

He, X.Y., He, Z.H., Morris, C.F., Xia, X.C. 2009. Cloning and phylogenetic analysis of polyphenol oxidase genes in common wheat and related species. Genetic Resources and Crop Evolution 56: 311-321.

Fuerst, E., Beecher, B.S., Xu, S.S. 2008. Genetic Characterization of Kernel Polyphenol Oxidases in Wheat and Related Species. Journal of Cereal Science 48:359-368.

Turuspekov, Y., Beecher, B.S., Darlington, Y., Bowman, J., Blake, T., Giroux, M. 2008. Hardness locus sequence variation and endosperm texture in spring barley. Crop Science 48:1007-1019.

Ross, A.S., Bettge, A.D. 2009. Chaper 20: Passing the Test on Wheat End-Use Quality. Pages 455-494. Wheat: Science and Trade. Ed: B.F. Carver.

Ma, D., Zhang, Y., Xia, X., Morris, C.F., He, Z. 2009. Milling and Chinese raw white noodle qualities of common wheat near-isogenic lines differing in puroindoline b allele. Journal of Cereal Science 50:126-130.

Randhawa, H.S., Mutti, J.S., Kidwell, K.K., Morris, C.F., Chen, X., Gill, K.S. 2009. Rapid and Targeted Introgression of Genes into Popular Cultivars Using Marker-Assisted Background Selection. PLoS One 4(6):e5752

Morris, C.F., Li, S., King, G.E., Engle, D.A., Burns, J.W. 2009. A Comprehensive Genotype and Environment Assessment of Wheat Grain Ash Content in Oregon and Washington -- Analysis of Variation. Cereal Chemistry 86:307-312.

Bettge, A.D., Kweon, M. 2009. Collaborative Study on updated Method 10-52: Baking Quality of Cookie Flour - Micro Method (Sugar-Snap Cookie). Cereal Foods World 54(2): 70-73.

Haynes, L., Bettge, A.D., Slade, L. 2009. Soft wheat and flour products methods review: solvent retention capacity equation correction. Cereal Foods World July-August 2009, Vol. 54, No. 4, 174-175.

Martin, J.M., Beecher, B.S., Giroux, M.J. 2008. White Salted Noodle Characteristics from Transgenic Isolines of Wheat Over Expressing Puroindolines. Journal of Cereal Science 48:800-807.

Last Modified: 7/28/2014
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