Location: Wheat Health, Genetics, and Quality Research
2019 Annual Report
Accomplishments
1. New statistical methodology identifies wheat cultivars with stable high falling numbers. Statistical methods for separating genetic and environmental effects were applied to a large dataset of falling numbers data collected over five years. Northwest farmers lost approximately $200 million to discounts due to low falling numbers in 2016. ARS researchers and collaborators at Washington State University in Pullman, Washington, examined the utility of statistical methods to identify resistant varieties based on over 15,000 falling numbers datapoints from testing of state extension variety trials performed since 2013. The results allow wheat breeders and farmers to identify varieties that had more stable higher falling numbers over many years and locations.
2. A new club wheat, Castella, is released for the intermediate rainfall region of Washington state. ARS scientists in Pullman, Washington, developed and released Castella club wheat, which is resistant to stripe rust, aluminum, and hessian fly, and possesses excellent club wheat end use quality. Club wheat is a significant part of the wheat export market in the Pacific Northwest, but current club wheat cultivars are either susceptible to low falling numbers, or susceptible to stripe rust. A combination of single seed descent, marker assisted selection and multi-location field trials was used to develop Castella club wheat from a cross with a diverse pedigree including breeding lines from Washington, New York, and Arkansas. This diverse pedigree has resulted in an unusual combination of traits in Castella that increase marketing opportunities for growers.
3. Two molecular markers are effective screening tools for seedling and adult plant resistance to stripe rust in Pacific Northwest germplasm. Two molecular markers, the YR17-SNP marker and a new marker, Yr_IWB12603, are being used to select for seedling and adult plant resistance to stripe rust (also known as yellow rust (Yr)). Although several molecular markers have been identified for stripe rust resistance, their use is limited in soft wheat breeding programs. ARS researchers in Pullman, Washington, examined several combinations of molecular markers in the ARS wheat breeding program and associated these with seedling and adult plant stripe rust resistance based on greenhouse and field trials. The SNP marker, Yr_IWB12603, for the QYr.wac-1B.1/Qyr.wpg-1B.2/ QYrMa.wgp-1BS locus on chromosome 1B is likely a new combination of genes for seedling and adult plant resistance in the same region as several other stripe rust resistance (Yr) genes. The use of these two markers provides an alternative to the use of markers associated with the stripe rust genes Yr5 and Yr15 and will increase the frequency of combined adult plant and seedling resistance to major stripe rust races.
4. The regulation of the plant hormone gibberellic acid, which is critical in seed dormancy and crop emergence, is highly specialized. The ‘GID1’ gibberellic acid (GA) receptors can both positively and negatively regulate seed germination. Mechanisms controlling seed dormancy and crop emergence, major factors determining preharvest sprouting resistance and yield, are not well understood. The plant hormone GA stimulates germination and seedling emergence, leading to an assumption that the GA receptors should also stimulate germination. ARS researchers in Pullman, Washington, used mutant analysis in Arabidopsis to learn that the ‘GID1c’ receptor stimulates germination, the ‘GID1b’ receptor represses germination, and the ‘GID1a’ receptor can both positively and negatively regulate germination in the dark. This reveals that GA receptor function can be highly specialized and are interesting targets for controlling preharvest sprouting and emergence.
5. A method of evaluating late maturity alpha amylase (LMA) in the field is developed to facilitate breeding for reduced LMA. A field-based late maturity alpha amylase (LMA) testing system was developed. Over half of northwestern winter wheat cultivars are susceptible to LMA, a problem that caused major losses due to low falling numbers in several years since 2012. ARS researchers in Pullman, Washington, developed a field LMA testing system and used this method to screen hundreds of wheat breeding and germplasm for LMA susceptibility. This work enabled wheat breeders to select against LMA susceptibility in their breeding programs.
6. Antibodies to specific wheat alpha amylase enzymes are developed for use in development of rapid assays for low falling numbers in wheat. Monoclonal antibodies to wheat alpha-amylase were raised. Problems with low falling numbers can result from either preharvest sprouting (the germination of mature grain on the mother plant) or a cold-induced defect during grain development called late maturity alpha-amylase (LMA). ARS researchers and Washington State University researchers in Pullman, Washington, raised monoclonal antibodies that specifically recognize wheat TaAmy1 or TaAmy1 and TaAmy2. These results enable the development of ELISA assays for wheat preharvest sprouting and LMA.
Review Publications
Ibba, M., Kiszonas, A., See, D.R., Skinner, D.Z., Morris, C.F. 2018. Mapping kernel texture in a soft durum (Triticum turgidum ssp. durum) wheat population. Journal of Cereal Science. 85:20-26. https://doi.org/10.1016/j.jcs.2018.10.006.
Ando, K., Krishnan, V., Rouse, M.N., Danilova, T., Friebe, B., See, D.R., Pumphrey, M. 2019. Introgression of a novel Ug99-effective stem rust resistance gene into wheat and development of Dasypyrum villosum chromosome specific markers via genotyping-by-sequencing (GBS). Plant Disease. https://doi.org/10.1094/PDIS-05-18-0831-RE.
Qie, Y., Liu, Y., Wang, M., Li, X., See, D.R., An, D., Chen, X. 2018. Development, validation, and re-selection of wheat lines with pyramided genes Yr64 and Yr15 linked on the short arm of chromosome 1B for resistance to stripe rust. Plant Disease. 103(1):51-58. https://doi.org/10.1094/PDIS-03-18-0470-RE.
Liu, L., Wang, M.N., Feng, J.Y., See, D.R., Chen, X. 2019. Whole genome mapping of stripe rust resistance QTL and race-specificity related to resistance reduction in winter wheat cultivar Eltan. Phytopathology. 109(7):1226-1235. https://doi.org/10.1094/PHYTO-10-18-0385-R.
Ge, W., Steber, C.M. 2018. Positive and negative regulation of seed germination by the Arabidopsis GA hormone receptors, GID1a, b, and c. Plant Direct. 2(9):e00083. https://doi.org/10.1002/pld3.83.
Gizaw, S.A., Godoy, J.G., Garland-Campbell, K.A., Carter, A.H. 2018. Genome-wide association study of yield and component traits in Pacific Northwest winter wheat (Triticum aestivum L.). Crop Science. 58(6):2315-2330. https://doi.org/10.2135/cropsci2017.12.0740.
Sanad, M.N., Smertenko, A., Garland Campbell, K.A. 2019. Differential dynamic changes of reduced trait model for analyzing the plastic response to drought phases: a case study in spring wheat. Frontiers in Plant Science. 10:504. https://doi.org/10.3389/fpls.2019.00504.
Kiszonas, A., Higgenbotham, R., Chen, X., Garland-Campbell, K.A., Bosque-Perez, N.A., Pumphrey, M., Rouse, M.N., Hole, D., Wen, N., Morris, C.F. 2019. Agronomic traits in durum wheat germplasm possessing puroindoline genes. Agronomy Journal. 111(3):1254-1265. https://doi.org/10.2134/agronj2018.08.0534.
