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United States Department of Agriculture

Agricultural Research Service

Research Project: SMALL GRAINS GENETICS AND GERMPLASM ENHANCEMENT
2009 Annual Report


1a.Objectives (from AD-416)
Objective 1: Develop, evaluate, and apply molecular tools, including molecular genotyping and transposon tagging, to small grains genetics and germplasm enhancement research. Sub-objective 1.A. Identify and characterize genes involved in barley seed phytate content using Ds-generated (low phytate) LP insertion mutants. Sub-objective 1.B. Improve the Ogle1040/TAM O-301 (OT) genetic linkage map by.
1)developing and mapping polymerase chain reaction (PCR) based markers and.
2)physically anchoring linkage groups to chromosomes using aneuploid oat stocks. Objective 2: Identify, map, and develop molecular markers for disease resistance and quality genes, and use these resources to move favorable alleles from National Small Grains Collection (NSGC) accessions and other sources into adapted plant types. Sub-objective 2.A. Identify wheat and barley landraces from the NSGC likely to possess unexploited genes for resistance to new virulent races of the stem rust pathogen. Sub-objective 2.B. Introgress quantitative and qualitative resistance to barley stripe rust into adapted germplasm via marker assisted selection (MAS). Sub-objective 2.C. Identify, map, and develop molecular markers for quantitative trait loci (QTL) in barley cultivars Azhul and/or Falcon conditioning high ß-glucan (BG) levels. Sub-objective 2.D. Map and introgress resistance to crown rust of oat into high-yielding Aberdeen germplasm via MAS. Objective 3: Develop improved barley and oat cultivars meeting the needs of conventional and specialty markets for both dryland and irrigated production systems. Sub-objective 3.A. Develop improved spring and winter malt barley and specialty cultivars. Sub-objective 3.B. Develop oat cultivars combining the enhanced levels of disease resistance from southern U.S. with the superior yield and quality of ARS-Aberdeen lines.

The objectives in our project are complementary and interconnected. Proven methods and existing germplasm will be used to develop commercial cultivars for growers, and innovative new resources will be developed to facilitate genetic investigations and to enhance the efficiency of future germplasm and cultivar development. These resources will be made available to other researchers and to the agribusiness community.


1b.Approach (from AD-416)
This project seeks to generate improved small grains germplasm, including barley and oat cultivars, and to develop and use genomic tools that will facilitate future germplasm improvements. Most of the work will focus on barley and oat improvement. However, wheat stem rust screening of landrace accessions from the National Small Grains Collection (NSGC) will be included as part of a coordinated ARS effort to mitigate the threat of emerging races. The germplasm improvement work for barley will focus on issues of importance in the intermountain west, such as improving winter malt barleys and developing specialty types to expand market opportunities for producers. The oat work has a more national focus with emphasis on disease resistance. The research aimed at improving methodologies and tools for genomic research and germplasm enhancement will produce new resources for researchers, such as Ds-generated mutant barley stocks, more PCR-based oat molecular, and a more complete oat genetic map. This project also seeks to integrate the work of several scientists to achieve greater efficiency and productivity by sharing facilities, materials, and ideas among the project team members. Replacing 5366-21000-016-00D. 7/03 Formerly 5366-21000-024-00D (3/08).


3.Progress Report
Transposon Tagging Research. The location and function of many genes in barley are unknown, which slows the improvement of complicated traits such as drought resistance and nutritional qualities. A system known as transposon tagging--in which a short, mobile genetic sequence called "Ds" can be induced to move into and abolish the function of genes--can be used to reveal the location, sequence, and function of genes. The first step in this system is to develop many plants each with a Ds in a different chromosomal location. Ds was induced to move in a previously-developed set of Ds-containing lines, and 7000 plants were genetically fingerprinted and the regions around Ds were sequenced to identify 60 plants that had Ds in new locations. In most cases, Ds appeared to be genes, and several plants showed abnormal traits, suggesting that Ds had inserted into important genes. Having these lines builds the barley transposon tagging system into a more useful and flexible resource, and at the same time creates mutations that can be valuable for the study of gene function and location in barley. Barley Stripe Rust Research. Barley stripe rust (BSR) is a fungal disease that causes frequent economic damage to spring and winter barley in the higher-rainfall regions of the Pacific Northwest, and which has the potential to cause significant damage to the expanding acreages of winter malting barley in more arid areas of Oregon, Washington, and Idaho. Because BSR does not occur in all locations every year, the necessary task of separating resistant and susceptible plants during early stages of the breeding process based on disease symptoms is unreliable and costly. Developing genetic markers associated with resistance genes will enable lab-based selection for resistance for speedier production of improved varieties. Our approach for the identification of useful markers relies on the development of multiple populations derived from crosses of two different susceptible and two different resistant parents; each population consists of from 100-400 lines that must be individually advanced via self-pollination for five generations. The resulting populations will allow reliable identification of genetic markers associated with resistance, which can then be used for lab-based resistance selection. Greenhouse facilities allow two generations of advance each year, and the work has progressed to include four populations advanced two generations, and a fifth population advanced four generations. New Spring Barley Varieties. Two spring high beta-glucan barley lines were delivered to the University of Idaho Foundation Seed stock program for production of registered seed. All potential seed production has been contracted for purchase by industry. These lines are greatly superior to available hulless high beta-glucan lines currently being grown. Beta-glucan in the human diet is of interest because of its effects in lowering cholesterol and stabilizing glucose metabolism and these new lines will provide enhanced levels of beta-glucan and increased yields compared to available cultivars.


4.Accomplishments
1. Charles Winter Malting Barley. New malting barley cultivars are needed by the brewing industry to keep barley competitive with other crops. ARS researchers in Aberdeen, ID, developed ‘Charles’, a winter two-rowed malting cultivar that was officially added to the recommended list by the American Malting Barley Association. Approximately 11,000 acres were grown under contract by commercial brewers in Idaho in 2009. In addition, Charles is being evaluated in Washington, Oregon, Montana, Colorado, South Dakota, Minnesota, and North Dakota. Charles will provide growers with added flexibility in crop management, reduced water use and increased yield potential compared to spring cultivars.

2. Oat Crown Rust Resistance Validated. Crown rust is the most important disease of oat worldwide and developing resistant varieties is the best way to control crown rust. Molecular markers associated with resistance allow rapid and convenient selection for resistance. To develop useful markers, ARS researchers in Aberdeen, ID, must first ‘validate’ resistance loci through testing in various environments. The crown rust resistance found at several loci in the oat genome was validated using multi-location trials and new methods to measure the disease resistance. These loci could be valuable in controlling crown rust and we plan to develop genetic markers that can be used to easily introduce them into improved oat cultivars. Controlling crown rust with natural disease resistance will help to boost the competitiveness of the US oat crop.

3. New Oat Genetic Markers Facilitate breeding Efforts. The lack of genetic markers in oat has impeded the development of a correct genetic map and inhibited marker-assisted breeding efforts. ARS researchers in Aberdeen, ID, worked with a consortium of scientists to develop a new automated platform for oat genetics research, know as diversity arrays technology (DArT), to quickly map 3,000 markers in the oat genome. Using the new markers, we generated the first complete genetic map of oat. The map will be useful in future oat genetics research and will contribute towards making oat a profitable crop.

4. New Genetic Maps for Barley. At present there are no genetic maps specifically developed to identify genes for soluble fiber, which has cholesterol-lowering properties, and the enzymes involved in malting quality in barley. ARS researchers in Aberdeen, ID, developed two new barley mapping populations. Over 700 genetic markers have been placed on the new maps and genetic areas controlling soluble fiber have been identified. In addition, new genetic regions controlling spike angle have been identified. This is an important finding, because spike angle affects the occurrence of a destructive disease known as Fusarium head blight. The results of this work should help breed better malting varieties in the future.

5. Endeavor Winter Malting Barley. New malting barley cultivars are needed by the brewing industry to keep barley competitive with other crops. A two-rowed winter malting cultivar 'Endeavor' was publicly released and is being evaluated by ARS scientists in Aberdeen, ID in plant-scale tests by a brewer at various locations throughout southern Idaho. Approximately 30,000 bushels will be produced for malting and brewing trials this year by US brewers. In addition, various Latin and South American malting and brewing companies are evaluating Endeavor in their plant-scale processes.


6.Technology Transfer

Number of New Germplasm Releases1

Review Publications
Gurung, S., Bonman, J.M., Ali, S., Patel, J., Myrfield, M., Mergoum, M., Singh, P.K., Adhikari, T.B. 2009. New and Diverse Sources of Multiple Disease Resistance in Wheat. Crop Sci. 49:1655-1666.

Last Modified: 12/22/2014
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