Location: Small Grains and Potato Germplasm Research
2018 Annual Report
Objectives
This project intends to produce improved barley and oat germplasm, and new information and techniques to facilitate increased efficiencies. The objectives below will be the specific focus for the next five years:
Objective 1: Develop barley and oat germplasm with increased yield, better quality, and superior or novel resistances to biotic and abiotic stresses.
• Subobjective 1A: Develop low protein barley lines suitable for all-malt brewing.
• Subobjective 1B: Develop improved winter food barley varieties.
• Subobjective 1C: Develop facultative malting barley.
• Subobjective 1D: Develop barley varieties with improved Fusarium head blight resistance.
Objective 2: Translate new, sequence-based information into breeder-friendly tools for crop improvement in barley and oats.
• Subobjective 2A: Map Fusarium head blight (FHB) resistance and develop germplasm resistant to multiple diseases via marker-assisted selection.
• Subobjective 2B: Map quantitative trait loci (QTL) from new sources of adult plant resistance to oat crown rust disease (OCR) and develop milling oat germplasm resistant to crown rust.
Objective 3: Develop and implement novel biotechnological tools to produce barley germplasm with unique traits and enhance understanding of the genetic mechanisms underlying key traits.
Subobjective 3A: Deliver a site-specific recombination (TAG) platform via Ds-mediated transposition, and demonstrate functionality for RMCE in barley.
• Subobjective 3B: Construct and deliver Ds-bordered RNAi constructs that are transposition competent and that confer resistance to Fusarium head blight.
• Subobjective 3C: Perform genetic analyses of seed total phosphorus and phytic acid in barley.
Approach
Objective 1: Productive varieties will be developed that are improved for agronomic performance, protein and beta-glucan contents, winter survival, and Fusarium head blight (FHB) resistance. Hybridization with generation advance in greenhouses, New Zealand, and by doubled haploids will be used for population development. Breeding efficiency will be enhanced by investigating the genetics of key traits to enable genomic selection and the development of novel selection schemes. Agronomic performance and FHB resistance will be assessed in multi-location field trials. Grain quality will be assessed by physical examination and chemical analysis of grain for malt quality, protein and beta-glucan contents, and mycotoxin content.
Objective 2: Research will relate genetic sequence to disease resistance. Incorporating resistance to diseases that constrain oat and barley production outside of the Intermountain West will make Aberdeen germplasm more valuable. Since Idaho locations have low disease, direct selection for resistance is difficult. Indirect selection of sequence-based markers associated with resistance will combine good agronomic performance and grain quality with resistance to rusts and blotches. For diseases with established markers, development of new lines with specific markers will precede field screening in disease-prone sites outside of Idaho and in greenhouses using artificial inoculation. For other diseases, such as oat crown rust, screening in disease-prone sites will measure disease in multiple test lines, and statistical associations between specific sequences and resistances will identify and “map” new markers. Hybridization, generation advance, and genotypic and phenotypic screens will establish new populations from which lines that have improvements in disease resistance, yield, and quality will be selected.
Objective 3: Research will develop tools for experimental genetic manipulations and knowledge of how phosphorus is stored in seeds. Phosphorus is a critical nutrient and a major water pollutant. The hypothesis that the gene lpa-M955 is responsible for reduced seed phosphorus will be investigated by investigating statistical associations between the gene and different levels of seed phosphorus as measured by chemical assays. The hypothesis that new mutations can be found that result in 25% less phosphorus but without negative impact on plant performance will be examined by finding low-phosphorus mutant seeds, and growing them and selecting healthy plants that will then be tested in greenhouses and fields. To facilitate future genetic engineering experiments to identify additional genes of importance, the hypothesis that causing test genes to “jump” (transpose) into specific locations will help answer genetic questions will be tested by attempts to move a test gene into a specially designed receiver site. To test the hypothesis that this process can be harnessed to produce a non-chemical method of controlling a fungus that produces toxins in crop seeds, transposition will deliver an antifungal gene, followed by greenhouse and growth chamber screening for the reduced ability of the fungus to grow and produce toxins.
Progress Report
This report documents progress for project 2050-21000-034-00D, which started February 2018 and continues research from 2050-21000-031-00D, "Genetic Improvement of Barley And Oats for Enhanced Quality and Biotic Stress Resistance" and 2050-21000-030-00D, "Analysis of the Biochemical Pathway and Genetics of Seed Phytate in Barley."
Work towards project objectives is in progress. Scientists are continuing to pursue advanced testing of three elite malting barley variety candidates in collaboration with industry. Multiple lines from backcross populations that were identified as having either low or high beta-glucan are being increased to enable experiments to verify the specific genes responsible for the altered beta-glucan levels. Scientists have responded to additional funding targeted specifically for Fusarium head blight research by taking several actions to increase germplasm evaluation capabilities. Additional equipment necessary for efficient nursery planting was purchased and additional genotyping services were arranged in anticipation of implementing a program of genomic selection for Fusarium head blight in elite malt and food barley germplasm. Significantly, a new collaborative agreement was negotiated with the University of Idaho for the development of a new Fusarium head blight nursery in southern Idaho. In addition, scientists are negotiating collaborative research with the ARS research Unit in Madison, Wisconsin to accomplish the additional malt quality phenotyping that genomic selection will require, and the process was initiated to hire a post-doctoral researcher who will focus on developing and implementing this project.
Work on resistance to oat crown rust, initiated in the last project and continuing for the new project, is moving forward. Seed from 1,590 oat accessions that had been obtained from the National Small Grains Collection (NSGC) and that had shown moderate to complete crown rust resistance in Baton Rouge, Louisiana, trials was planted in Saint Paul, Minnesota, for further assessment. Some level of crown rust resistance at both locations was identified in 94 accessions, and these were further screened in growth chamber tests to differentiate between those with seedling stage resistance and those with adult plant resistance. These accessions trace to crosses and selections made many decades ago. Their identification was made possible with collaboration with University and ARS collaborators at several locations, and they demonstrate the value of the NSGC for continued breeding progress. Pure lines have been created from these accessions for use as parents in population development.
Work on barley stripe rust resistance also is being continued from the previous project. Trials (2017—2018 winter season) in Davis, California and in Corvallis, Oregon are now complete and have delivered data that will be useful for identifying adult plant resistance derived from the germplasm line 95SR316A. Markers identified in the previous project have been used to select lines with all possible combinations of resistance alleles derived from the landrace Grannenlose Zweizeilige in a backcross population created with 95SR316A. It is expected that this population will have lines with the elite performance of 95SR316A with the additional seedling resistance of Grannenlose Zweizeilige. Seed increases were conducted that will enable testing selections from this population in the 2018—2019 winter season.
Several lines of inquiry related to biotechnological tool development continue in the new project. Experiments to determine the functionality of recombinase mediated cassette exchange in barley have begun. This technique is a process for precise transgene insertion, and plants developed and identified in the prior project with recombination platforms delivered by a process of transposition are being used for these experiments. Experiments to introduce a gene construct designed to silence a key Fusarium gene for mycotoxin production have been initiated. This construct, identified in the previous product via a rapid, Fusarium-based testing platform, is expected to result in a process of host-induced gene silencing, where the invading pathogen will be unable to properly function when affected by this gene construct.
Accomplishments
Review Publications
Yimer, B., Gordon, T.C., Harrison, S., Kianian, S., Bockelman, H.E., Bonman, J.M., Esvelt Klos, K.L. 2018. New sources of adult plant and seedling resistance to Puccinia coronata f. sp. avenae identified among Avena sativa accessions of the national small grains collection. Plant Disease. https://doi.org/10.1094/PDIS-04-18-0566-RE.
Anwar, N., Ohta, M., Yazawa, T., Sato, Y., Li, C., Tagiri, A., Sakuma, M., Nussbaumer, T., Bregitzer, P.P., Pourkheirandish, M., Wu, J., Komatsuda, T. 2018. miR172 down-regulates the translation of cleistogamy 1 in barley. Annals Of Botany. https://doi.org/10.1093/aob/mcy058.
Tripathi, R.K., Singh, J., Bregitzer, P.P. 2018. Genome-wide analysis of the SPL/miR156 module and its interaction with the AP2/miR172 unit in barley. Scientific Reports. 8:7085. https://doi.org/10.1038/s41598-018-25349-0.
