CHARACTERIZATION OF STRESS RESISTANCE GENES AND MECHANISMS, & IMPROVEMENT AND GENOTYPING OF WHEAT AND BARLEY GERMPLASM FOR THE WESTERN U.S.
Location: Wheat Genetics, Quality Physiology and Disease Research
Title: Using the solvent retention capacity test when breeding wheat for diverse production environments
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 9, 2007
Publication Date: January 3, 2008
Citation: Walker, C., Garland Campbell, K.A., Carter, B., Kidwell, K. 2008. Using the solvent retention capacity test when breeding wheat for diverse production environments. Crop Sci. 48: 495-506.
Interpretive Summary: Evaluation of wheat end use quality is an important component of wheat improvement programs due to the need for new varieties to meet current marker demands. The solvent retention capacity tests are useful methods of evaluating wheat end use quality but small scale 5 and 0.2 g SRC tests have not been evaluated for their predictability in wheat breeding programs. This research indicated that predictability of SRC tests were high for the larger 5g samples and were acceptable for two of the SRCs, lactic acid and sucrose, at the smaller 0.2g scale. The lactic acid SRC predicts protein quality and the sucrose SRC predicts starch damage. Thus, the SRCs can be used early in wheat breeding programs but to be most predictive, evaluation should occur across environments. These results give breeders a method of assessing use of limited resources to set up quality evaluation procedures in their breeding programs.
The solvent retention capacity (SRC) test is used to predict commercial baking performance of soft wheat (Triticum aestivum L.) by measuring the capacity of flour to retain each of four sol- vents—water, Na 2CO3, sucrose, and lactic acid— to assess overall absorption capacity, starch damage, pentosan and gliadin content, and glutenin quality, respectively. Our objectives were to determine sources of variation in the test, repeat- ability, and optimum scale and resource alloca- tion needed to maximize efficiency. Duplicate SRC tests were conducted for each solvent using two flour sample sizes (5 and 0.2 g) from two field replications of each of 8 soft white spring and 16 soft white winter genotypes grown in five and three environments, respectively. We con- ducted ANOVAs and used variance components to assess the consistency with which genotypic differences were detected. The interactions of genotype × environment and genotype × field replication within environment were significant (P < 0.05) for most solvent and sample weight combinations. Repeatability values were high and consistent for all solvents (0.86–0.96) when 5-g samples were used, indicating that selection based on any solvent should result in gains from selection at this scale. Only lactic acid and sucrose were accurately predictive at the 0.2-g scale, limiting its utility. Repeatability values improved with increased numbers of environments, field replications, or laboratory replications; however, this may be cost prohibitive when evaluating early-generation breeding material on a large scale, especially since the magnitude of increase in predictability diminished with each additional unit.