Location: Forage and Range Research2010 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
Breeding efforts at the Forage and Range Research Laboratory (FRRL) to collect, characterize, evaluate, and develop improved plant materials for turf, pastures, and rangelands adapted to the western United States continues in native and introduced legumes (spreading alfalfa, prairie clovers, cicer milkvetch, Kura clover, sainfoin, birdsfoot trefoil, and Utah sweetvetch), forbs (globemallow, small burnet, and forge 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, timothy, and creeping foxtail), and low-maintenance turf grasses (bluegrasses, fine fescues, and crested WG). Traits of interest include increased forage yield and quality (CP, NDF, IVTD, and lignin), seed yield, germination, establishment, drought tolerance (persistence), heat tolerance, water stress, salinity tolerance, abiotic stresses, and turf quality. Irrigated pastures work has resulted in the development of two experimental orchardgrass synthetics (early maturing and late maturing), currently under a CRADA. Seed collections from Kyrgyzstan, China, and Russia were evaluated for their potential for reduced-input turfgrass applications. Over 200 bluebunch wheatgrass collections from the Great Basin were evaluated for germination and seedling emergence. Field and DNA-fingerprinting studies describing patterns of genetic diversity for western and Searls prairie clover, North American wildryes, and fine fescues. DNA genotyping of an Elymus genetic mapping population with AFLP and SSR microsatellite markers resulted in a consensus genetic map of Elymus lanceolatus that contains all 14 linkage groups. Genetics tools including EST-SSR markers continue to be developed in wildryes (Leymus sp.), wheat grasses (Elymus sp.), Thinopyrum sp., orchardgrass (Dactylis sp.), and bluebunch wheatgrass (Pseudoroegneria sp.) for rhizome development, flowering, heavy metal uptake, plant height, winter hardiness, and salinity tolerance. Phenotypic measurements to determine the affect of marker-assisted selection for the seed-retention gene in advanced Leymus breeding populations were measured. DNA finger printing protocols to differentiate species of mannagrass from annual ryegrass and populations of Poa sp. were developed. As part of our technology transfer program, the FRRL continues to work via Material Transfer Agreements with private growers to evaluate improved genetic material and increase commercial seed production of western and Searls prairie clover and Recovery western wheatgrass for commercial seed production. Foundation seed production of a rhizomatous grazing/rangeland alfalfa was initiated. Three different ecosystems in the Great Basin were evaluated using paired sets of historically dry-farmed land and adjacent areas that have never been cultivated. This research identified that land-use legacies of dry farming have striking consequences on vegetation recovery for nearly a century after cultivation has ceased.
1. Characterization of Thinopyrum junceum chromosomes carrying useful genes for resistance to biotic and abiotic stresses. Chromosomes in polyploid species, such as Th. junceum, often had undergone structural rearrangements in relation to chromosomes in ancestral diploid species. Thus, genes encoding for a valuable trait in the polyploid species may not be the same genes in the diploid species. ARS researchers in Logan, Utah, have determined the homology and structural organization of Th. junceum chromosomes in 13 cytogenetic stocks, among which tolerance to salinity and resistance to stem rust have been found. Having this information, plant breeders will be able to efficiently utilize these valuable traits to improve various crops.
2. Separation of individual alfalfa proteins for differential ruminal degradation. Alfalfa protein is rapidly broken down in the rumen resulting in loss of nitrogen as an environmental pollutant and lost animal nutrition. A method was developed by ARS scientists in Logan, Utah, that was shown to separate individual alfalfa proteins for their rate of degradation within alfalfa. This tool can be utilized in the development of alfalfas with reduced ruminal protein degradation that would provide a global benefit to the livestock industry, particularly the dairy industry. This was reported in the Canadian Journal of Plant Science and voted the Top 2009 Agronomy paper by the Canadian Plant Science Society.
3. Forage kochia increases livestock carrying capacity of western rangelands. Low forage production and poor nutritional content of western rangelands limits their value for fall and winter grazing. An ARS scientist in Logan, Utah, in cooperation with animal scientists with Utah State University, compared the carrying capacity and livestock performance of traditional winter pastures dominated by crested wheatgrass (Agropyron desertorum) and cheatgrass (Bromus tectorum) versus similar rangelands seeded with forage kochia (Kochia prostrata) and crested wheatgrass. The rangelands with forage kochia had higher crude protein, and increased carrying capacity by six-fold as compared to the non-treated rangelands. Cattle on rangelands with forage kochia tended to have higher increases in body condition than cattle on the crested wheatgrass/cheatgrass rangelands. This research was important for showing that seeding western rangelands with forage kochia can improve sustainability of livestock production in the western U.S. by providing increased amounts of nutritious forage during the fall and winter.
4. Development of a genetic linkage map for Elymus. Several grasses native to the Intermountain region of the Western U.S. belong to the genus Elymus, which is the largest and most complex genus in the Triticeae tribe with approximately 150 polyploid perennial grass species occurring worldwide. ARS researchers in Logan, UT have developed backcross mapping populations of two species, Elymus wawawaiensis and Elymus lanceolatus, which have divergent growth habit traits, but share the StH genomic constitution. These populations were genotyped with markers to generate a consensus genetic linkage map which contains a total of 14 linkage groups, with a full complement of seven linkage groups assigned to each of the St and H genomes. This genetic map will be useful for mapping important growth habit traits in these important perennial grasses.
5. Land-use legacies of dry farming in the Great Basin. Revegetation success is often poor because past disturbances severely altered vegetation and soils. In particular, the impacts of the once common practice of dry farming throughout the Great Basin have not been comprehensively evaluated even though millions of acres of land were cultivated and then abandoned after the dry farming boom from 1910-1920. Because the primary mission of ARS scientists at the Forage and Range Research Laboratory in Logan, Utah is to develop plant materials for revegetation, understanding ecosystem properties, especially vegetation and soils of disturbed regions is critical. In 2010 a detailed evaluation of three different ecosystems was conducted in the Great Basin, using paired sets of historically dry-farmed land and adjacent areas that have never been cultivated. This research identified that land-use legacies of dry farming have striking consequences on vegetation recovery for nearly a century after cultivation has ceased. Land-use legacies in sagebrush ecosystems have direct implications for quantifying ecosystem health, and to make informed predictions about how ecosystems respond to restoration and re-vegetation efforts. Combined, this novel research will not only assist with developing more appropriate management strategies for reducing the impacts of invasive species on formerly disturbed lands, but provides definitive “soil and vegetation” indicators to directly assist the selection of plant materials to remedy disturbed soils and the development of improved plant materials.
6. Production of hybrid seed for wind-pollinated perennial grasses. Hybrids of divergent plant varieties and species often display superior productivity; however efficient methods for hybrid seed production are limited to a relatively small number of crop species with separate male and female flowers, such as maize. Most perennial grasses have perfect flowers with male and female structures, but can’t self-pollinate and produce true-breeding varieties. ARS scientists in Logan, Utah, developed a relatively simple and efficient method of hybrid seed production for wind-pollinated perennial-grasses, based on clonal propagation of one rhizomatous seed-parent plant that is forced to hybridize with divergent pollen parents. In this study, hybrid seed was developed between rhizomatous and one non-rhizomatous Elymus wheatgrass species and between rhizomatous and one non-rhizomatous Leymus wildrye species. Results suggest that similar methods could work with other perennial grasses to the extent that clonal reproduction of one seed-parent plant is possible. Hybrid seed production of perennial grasses will provide opportunities for improved forage and biomass production of perennial grasses.
7. Identification of benefical fungi in fine-leafed grass populations (Festuca valesiaca and F. rubra) populations. Fine-leaf grasses have the potential for use as turfgrass in low-input growing environments (low water and fertilizer) in the arid western U.S. Their use can be enhanced by plant fungi (i.e., endophytes) that work to improve the plants response to environmental stresses such as heat, drought, and salt. Fine-leafed grasses from Kyrgyzstan and China were evaluated by scientists at the Forage and Range Research Lab at Logan, Utah, for the presence of endophytes. Plants that possessed endophytes were isolated and cultured in tissue culture to determine their type (species) and whether they possessed non-toxic substances detrimental to animals. Endophytes have been identified in various grasses and in some cases these endophytes had the ability to enhance the performance of plants in harsh growing environments (i.e., drought and high heat). If the endophytes could be transferred to commercial cultivars, then their agronomic and horticultural potential could be enhanced (ability to consume less water and fertilizer), which could help to conserve natural resources in the arid western U.S. and allow for the adaptations needed under extreme global climate change.
5. Significant Activities that Support Special Target Populations
During 2010, the Forage and Range Research Lab conducted on outreach program that included speakers from FRRL and surrounding University Extension Specialists. These sites included Kanab UT; St. George UT; Dillon MT; Billings MT; and Ritzville WA. These programs addressed the following subjects; pasture grasses and legumes, adaptation of rangeland plants (grasses, forbs, and legumes), when and how to plant rangelands, and seeding mixtures. Attendance at each meetings ranged from 25 to 180 and included ranchers, farmers, and public land agencies. Distributed at each program were handouts and the ‘Intermountain Planting Guide’. Given the response of the last four years to program survey’s we will continue to go out each year.
Robins, J.G. 2010. Cool-Season Grasses Produce More Biomass Across the Growing Season than do Warm-Season Grasses when Managed with an Applied Irrigation Gradient. Biomass and Bioenergy. 34:500-505.