1a. Objectives (from AD-416):
1. In cooperation with breeders and geneticists, identify and facilitate the manipulation of genetic variation of end use quality characteristics in western wheat. Specific end-use quality traits to be studied include: kernel texture (sub-objective 1a), starch and non-starch carbohydrates (sub-objective 1b), polyphenol oxidase activity (sub-objective 1c), and overall milling and baking performance of wheat breeding lines (sub-objective 1d). Sub-Objective 1a. Alter wheat kernel hardness characteristics by identifying and incorporating novel puroindoline gene alleles and texture-related QTLs. Sub-Objective 1b. Determine the degree to which manipulation of polysaccharide content and structure can affect the end-use quality characteristics of wheat flour. Sub-Objective 1c. Determine the degree to which the many polyphenol oxidase genes in wheat impact noodle dough color stability. Sub-Objective 1d. Develop wheat cultivars with superior end-use quality characteristics in collaboration with regional wheat breeders and geneticists. 2. Develop, modify, and evaluate technologies and methodologies for measuring wheat kernel characteristics that impact end use functionality. Specific characteristics to be measured include: Kernel texture (sub-objective 2a), arabinoxylan composition (sub-objective 2b), gluten quality (sub-objective 2c) and polyphenol oxidase activity (sub-objective 2d). Sub-Objective 2a. Determine the reliability and performance of an endosperm brick test developed at the WWQL. Sub-Objective 2b. Develop a diagnostic assay for oxidative gelation of arabinoxylans in flour batters using free-radical-induced/peroxidase-mediated oxidative cross-linking. Sub-Objective 2c. Test a recently developed laser-based prototype instrument for measuring gluten strength via SDS-sedimentation (in collaboration with Dr. Rangan Chinnaswamy, GIPSA) Sub-Objective 2d. Modify our existing PPO L-DOPA assay to identify very low levels of grain PPO. 3. Identify and manipulate the biochemical constituents of wheat to improve the nutritional functionality of grain and flour, specifically dietary fiber and antioxidant content.
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 polyphenol oxidase 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:
This work falls under NP306. Progress was made on all three objectives and their sub-objectives. (1a) Over 1,000 Aegilops tauschii accessions were obtained and several hundred were grown in the greenhouse, nearly all have been haplotyped for the puroindoline genes. (1b) Crosses were made between waxy germplasm and Stephens, MDM and Xerpha; plots were grown at the WSU agronomy farm. (1c) A new family of PPO genes expressed in developing wheat kernels was identified and the three members named PPO-A2, PPO-B2, and PPO-D2. The chromosomal locations of the five PPO genes known to be expressed in the kernel have been determined through genetic mapping. The relative expression levels of these new PPO genes as well as the previously identified PPO-A1 and PPO-D1 genes were measured. (1d) The 2011 harvest breeder sample evaluations were completed. (2a) Research on kernel texture using endosperm bricks was completed. (2b) Bostwick viscosity test was essentially completed and manuscripts were published. (2c) Collaboration with Dr. Chinnaswamy, GIPSA, was completed on our laser-based gluten meter. Our SDS sedimentation instrument was used to analyze wheat samples and showed that the laser-diodes were capturing substantive gluten quality information. (2d) The work on this sub-objective has been temporarily placed on hold. (3) Over 1,000 Regional Nursery samples were obtained in furtherance of an AFRI/NIFA grant; milling and baking tests were completed.
Morris, C.F., Anderson, J.A., King, G.E., Bettge, A.D., Garland Campbell, K.A., Fuerst, E.P., Beecher, B.S. 2011. On the occurrence of a unique 'super soft' kernel trait in wheat. Cereal Chemistry. 88:576-583.