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United States Department of Agriculture

Agricultural Research Service

Research Project: IMPROVED PLANT GENETIC RESOURCES FOR PASTURES AND RANGELANDS IN THE TEMPERATE SEMIARID REGIONS OF THE WESTERN U.S.

Location: Forage and Range Research

2013 Annual Report


1a.Objectives (from AD-416):
Evaluate and develop new germplasm and cultivars with enhanced seed production, germination, seedling vigor, salinity tolerance, winter hardiness, drought tolerance, and forage yield and quality and verify their ability to improve the sustainability and productivity of rangelands and pastures in the semiarid western U.S. • Objective 1: Collect, characterize, and evaluate grass, legume, and forb germplasm for genetic variation, adaptation, establishment and forage characteristics for use on Western rangelands and the rangeland-urban interface. • Objective 2: Describe and identify useful traits for improved forages, using physiological, biochemical, and genomic techniques. • Objective 3: Identify breeding and selection strategies to make plant selection more effective. • Objective 4: Develop germplasm/pre-variety germplasm/cultivars of grasses, legumes, and forbs with improved seed production, seedling establishment, forage production, persistence, and drought tolerance on rangelands of the Western U.S. • Objective 5: Develop and evaluate new plant cultivars that are more tolerant of biotic and abiotic stresses, more competitive, more persistent, and easier to establish and maintain in irrigated pastures in the Intermountain West. • Objective 6: Identify functional differences between invasive weeds and improved plant materials and evaluate potential methods and improved plant materials to diversify crested wheatgrass communities.


1b.Approach (from AD-416):
Combine expertise of a research team of plant breeders, plant physiologists, ecologists, and molecular biologists to acquire, characterize, and breed native and introduced range, pasture, low-maintenance turf, and bioenergy plant materials. There is a need for additional plant materials for the conservation, restoration, renovation, and reclamation of range and forage lands, including irrigated pastures. New releases will provide improved plants needed to establish and maintain economically and environmentally sustainable pastures and rangelands in the semiarid regions of the Intermountain West. Identify new sources of genetic diversity for cultivar development. Describe establishment of grasses, legumes, and forbs characteristics such as ability to sustain high quality forage on disturbed sites under grazing pressure when competing with invasive weeds, and important physiological and biochemical mechanisms. Molecular and cytogenetic approaches will be used to identify and characterize genetic mechanisms to improve efficiency of genetic enhancement and plant breeding. The competitive ability of released plant materials will be enhanced for traits such as seed germination, seedling vigor, rhizome development, salinity tolerance, drought tolerance, and forage quality and yield. The new plant materials will be evaluated for their improved ability to perform key ecological functions, satisfying the diverse needs of our customers. Evaluate potential invasiveness of new plant germplasm.


3.Progress Report:
This is the final report for project #5428-21000-012-00D. Western rangelands continue to be invaded by invasive plant species (i.e., halogenton, cheatgrass, medusahead wildrye), which cause an increase in wildfire frequency and intensity. Scientists at Logan's Forage and Range Laboratory (FRRL) continue to focus on developing improved plant materials for turf, pastures, and degraded rangelands adapted to the western United States in native and introduced legumes (spreading alfalfa, prairie clovers, cicer milkvetch, Kura clover, Lewis flax, sainfoin, birdsfoot trefoil, Utah trefoil, and Utah sweetvetch), forbs (small burnet and forage kochia), dryland range grasses (crested and Siberian wheatgrass (WG), bluebunch WG, thickspike WG, Snake River WG, western WG, Russian wildrye (WR), bottlebrush squirreltail, and slender wheatgrass), irrigated pasture grasses (tall fescue, orchardgrass, meadow brome, and timothy), and low-maintenance turf grasses (bluegrasses, fine fescues, and crested WG). Traits of interest include seed yield, germination, establishment, drought and heat tolerance, water stress, salinity tolerance, winter hardiness, turf quality, and increased forage yield and quality. Efforts are currently underway to establish forage kochia and wheatgrass species on the scablands of central Washington to compete with cheatgrass and medusahead and reduce animal intake of lupine (poisonous plant) to reduce the incidence of crooked calf syndrome. Research continues to develop improved grass, legume, and forb germplasm with increased forage nutritional quality for fall and winter grazing by livestock and wildlife, which could reduce winter feeding costs up to 25% or more. Molecular map development and genome sequence analysis of pasture and turf grasses continues at the FRRL. In cooperation with forage breeders, FRRL scientists generated thousands of gene sequences from orchardgrass, Kentucky bluegrass, basin wildrye, and alfalfa. The orchardgrass markers were used to construct a genetic linkage map of the species that now has molecular markers associated for traits including late flowering and winter hardiness. Gene sequences were also used to investigate the molecular relationships of major North American orchardgrass varieties, which resulted in the development of unique genetic pools for future breeding programs. The Kentucky bluegrass markers are also being used to show molecular relationships and to identify hybrids in this genetically challenging species. The alfalfa markers are being used to show relationships between salt tolerant and non salt tolerant alfalfa lines in hopes of identifying pathways responsible for increased salinity tolerance. Mapping populations were developed or are being developed for fine fescue and intermediate wheatgrass. Additional research progress is described in the new replacement project 5428-21000-014-00D ‘Develop Improved Plant Genetic Resources to Enhance Pasture and Rangeland Productivity in the Semiarid Regions of the Western U.S.’ annual report.


4.Accomplishments
1. Developing improved plant materials for the Western U.S. rangelands. The invasion of weedy annual grasses following disturbance (grazing, wildfires, or human) is increasing on our western rangelands. This leads to an increase in wildfire frequency that destroys rangeland diversity, increases soil erosion and loss of air quality, and wildlife and livestock habitat and feed costing billions of dollars to the U.S. agricultural economy. Currently there is a lack of improved perennial plant materials that will establish, persist, and that are competitive against the invasion of weedy annual grasses available commercially for use. To meet these demands, scientists at the Forage and Range Research Laboratory (FRRL) have developed and released improved plant materials of Indian ricegrass, Snake River wheatgrass, basin wildrye, bottlebrush squirreltail, western wheatgrass, Siberian wheatgrass, crested wheatgrass, alfalfa, basalt milkvetch, western prairie clover, and forage kochia. Improved plant materials have demonstrated an increased ability to establish, persist, and reduce the invasion of weedy annual grasses on range sites that experience frequent drought, hot temperatures, disturbance, and frequent wildfires. These plant materials provide additional options for public and private land managers in their fight to restore our western rangelands to a stable productive ecosystem. Seed is available commercially for most of these plant materials.

2. Understanding genetic diversity of native range plants across the landscape. Currently, there is an increase by public and private land managers to use plant materials that are genetically similar to native (local) communities when revegetating our western rangelands after disturbance. However, little information is known regarding the patterns of genetic diversity of these plant materials across a landscape scale (many acres). Utilizing molecular genetics techniques, ARS scientists at the FRRL in Logan, UT, characterized the patterns of genetic diversity in Idaho and Roemer’s fescue, bluebunch wheatgrass, Snake River wheatgrass, slickspot peppergrass (results used by the U.S. Fish and Wildlife Service (USFWS) in making their decision not to list slickspot peppergrass on the endangered list), Utah sweetvetch, mannagrass (currently being used by APHIS, Bio security Australia, and Oregon Dept. of Agriculture as an official testing protocol), basalt milkvetch, western prairie clover, small burnet, and orchardgrass. This work defined the differences between self- and cross-pollinating species and led to the development of improved plant materials that are genetically similar to local communities.

3. Develop molecular tools for grass breeding. Until recently, molecular genetics tools (i.e., maps, markers, etc.) were limited for many of the grass species. The development of DNA maps and associated gene markers is critical for the continued development of improved plant materials better adapted to establishment, persistence, drought, increased salinity, and freezing tolerance. ARS scientists at the FRRL in Logan, UT, developed DNA maps and markers in alfalfa, basin and creeping wildrye, thickspike and Snake River wheatgrass, bluebunch wheatgrass, and orchardgrass. They have completed the sequencing and mapping of expressed gene sequences from perennial grasses and alfalfa to characterize genes associated with seed retention, rhizome development, seed germination, self-incompatibility, forage quality, forage production, heavy metal uptake, winter survival (orchardgrass), and flowering habit (orchardgrass; late versus early). These new genomic resources will enable the improvement of perennial plants materials for pasture and rangelands and act as a source of disease and insect resistance for cultivated wheat.

4. Identify functional differences between invasive weeds and improved plant materials. In developing new plant materials it is critical to identify traits that will give the improved plant materials a competitive advantage over the already aggressive annual weeds. This research identified:.
1)key differences (agronomic and physiological traits) between invasive grasses and forbs from perennial plant materials; and.
2)how to increase plant biodiversity using these differences to the advantage of perennial plant materials. ARS scientists at the FRRL in Logan, UT, demonstrated that improved grasses, forbs, and shrubs better synchronize their growth with nitrogen uptake more effectively in the spring and that forage kochia takes up water three times faster and from a great surface area than annual weeds; thus reducing or eliminating the invasion of weedy annuals in rangeland seedings. This research illustrates that the use of improved perennial plant materials are critical to resisting invasion by annual grasses and that rangelands planted to different species in a mixture with a combination of shallow, intermediate, and deep rooting depths provide an overall resistance to invasion by invasive weedy species.


Review Publications
Robins, J.G., Jensen, K.B., Jones, T.A., Waldron, B.L., Peel, M., Rigby, C.W., Vogel, K.P., Mitchell, R., Palazzo, A.J., Cary, T.J. 2013. Stand establishment and persistence of perennial cool-season grasses in the Intermountain West and Central and Northern Great Plains. Rangeland Ecology and Management. 66:181-190.

Last Modified: 8/29/2014
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