Location: Forage and Range Research
2024 Annual Report
Objectives
The semiarid rangelands, irrigated pastures, and turfgrasses of the western U.S. provide a broad array of critical ecosystem services, but invasive weeds, frequent drought, hotter temperatures, wildfires, and other disturbances are increasing the rate of rangeland and pasture degradation and threaten their long-term productivity. Therefore, the long-term objective of the Forage and Range Research Lab (FRR) is to develop resilient, weed resistant, and productive plant materials and methodologies to help prevent and solve these important natural resource issues. Research will be in the areas of (1) Rangeland Conservation and Restoration, and (2) Pasture and Turf Productivity and Sustainability. Specifically, during the next five years we will focus on the following five objectives:
Objective 1: Develop new plant materials for pasture, rangeland, and turf systems with increased resilience to harsh and variable environments.
Sub-objective 1A: Identify populations of bluebunch wheatgrass wheatgrass [Pseudoroegneria spicata (Pursh) Á. Löve] with superior seedling development under environmental fluctuations.
Sub-objective 1B: Elucidate the genetic basis and extent of genotypic variation for drought and salt tolerance in common pasture, rangeland, and turf grasses.
Sub-objective 1C: Develop pasture and rangeland grass and legume cultivars and germplasm with improved cold, salt, and drought tolerance.
Objective 2: Develop new plant materials and management practices that decrease the impact of invasive species and improve productivity, utility, and restoration of semiarid rangelands.
Sub-objective 2A: Develop weed resistant plant materials with improved seed yield, seedling establishment, and persistence for conservation and restoration of rangelands.
Sub-objective 2B: Identify seeding methodology that increases establishment of desirable plants and reduces weed invasion on rangelands.
Objective 3: Develop new plant materials with improved nutritive value and forage productivity, thereby increasing livestock performance and carrying capacity of pastures and rangelands.
Objective 4: Develop new turfgrass plant materials with improved aesthetic value when grown under reduced maintenance conditions.
Sub-objective 4A: Identify genetic methods that improve the efficiency of developing reduced-maintenance turfgrass germplasm.
Sub-objective 4B: Determine the extent of Genotype x Environment x Management (GxExM) interactions on reduced maintenance turfgrass performance.
Objective 5: Identify efficient pasture and rangeland-based grazing strategies that simultaneously improve economic and environmental sustainability of livestock production.
Approach
Traditional plant breeding, augmented by genomics and ecology, multi-location field evaluation, greenhouse microcosm experiment, deficit irrigation and physiological, genomic and molecular marker approaches will be used to achieve project objectives.
Sub-objective 1A: Seedling mortality is a threat to revegetation success in semiarid ecosystems. Microcosm experiments will determine the variation for seedling response to environmental gradients of temperature, soil moisture, and nutrients.
Sub-objective 1B: Deficit irrigation experiment will determine the feasibility of meadow fescue for the western U.S. Physiological and molecular markers will elucidate the response of turf species to drought and salt stresses; identify and characterize the alien Triticeae genes in wheat that confer salt tolerance and stem rust resistance; and create a DNA map of drought genes in bluebunch wheatgrass.
Subobjective 1C: Multi-location evaluation will be employed to develop winter-hardy, drought-tolerant, and/or salt-resistant germplasm of orchardgrass, timothy, and alfalfa.
Sub-objective 2A: Native grasses and legumes often lack seed production and establishment. Utah sweetvetch, basalt milkvetch, and Salina wildrye germplasms with improved seed production will be developed. The effect of pre-plant seed treatment on establishment of Utah trefoil will be determined. Genomic selection’s (GS) greatest benefit is when phenotypic evaluation is ineffective; therefore, the potential of GS to improve seed production and establishment in rangeland species will be determined using bluebunch wheatgrass as a model.
Subobjective 2B: Many Conservation Reserve Program and Bureau of Land Management plantings in the western U.S. are unsuccessful due to poor establishment of native grasses, legumes and forbs. Seed mixtures that increase seedling establishment success in semiarid regions will be identified. Rapid root development, a potential trait enabling perennial grass seedlings to compete with annual grasses, will be quantified.
Objective 3: Recurrent and genomic selection and will develop tall fescue, meadow bromegrass, and tall and intermediate wheatgrass germplasms with improved nutritive value throughout the grazing season. Candidate genes for digestibility will be identified in perennial ryegrass using ribonucleic acid
sequencing (RNA-seq) and quantitative trait loci (QTL) analyses.
Sub-objective 4A: Kentucky bluegrass and hard fescue have complex genomes that slow their genetic improvement. Genomic and molecular marker approaches will characterize and find functional genes for reduced-maintenance traits.
Subobjective 4B: Turfgrass irrigation is not environmentally sustainable, therefore, wheatgrass, bermudagrass, and zoysiagrass will be characterized in mixtures and for color retention in cold temperatures.
Objective 5: Reduced dry matter intake (DMI) of pasture by grazing cattle is a major factor limiting livestock performance. Grass-legume pastures that require fewer inputs, have high mass and nutritive value, and have high DMI will be identified.
Progress Report
This is the final report for project 2080-21000-018-000D, "Improved Plant Genetic Resources and Methodologies for Rangelands, Pastures, and Turf Landscapes in the Semiarid Western U.S.", which has been replaced by new project 2080-21500-002-000D. For additional information, please see the new project report.
In support of Objective 1, to increase plant resilience, ARS researchers in Logan, Utah, completed experiments to evaluate bluebunch wheatgrass seedling establishment. Seedling growth following exposure to drought, heat, cold, and nutrients was studied to generate a comprehensive database of leaf and root traits for further evaluation within genomic prediction models. Among these stresses, the most variability was for cold response and will be studied further in the new project. Researchers evaluated salinity tolerance of turf species using overhead irrigation. Salt tolerant Kentucky bluegrasses were found, and it was determined that responses were different and variable among species and varieties, which facilitated recommending the proper cultivars for salt affected areas. Identifying the types of genes conferring salinity tolerance is continuing in the new project. The identification of genes controlling salinity tissue tolerance in two grass wild relatives of bread wheat was completed by examining hybrids of wheat with these wild relatives. A single dominant gene was identified that conferred sodium exclusion (avoidance mechanism), whereas two recessive genes were involved in conferring tissue tolerance (high sodium content – resistance). Alfalfa is sensitive to salt stress, therefore, an alfalfa population with improved salt tolerance and forage production was developed. The new alfalfa germplasm had 20% greater forage production, greater root growth, reduced stomatal conductance, and lower sodium accumulation under salt stress than its parents and will be evaluated in the new project.
ARS researchers in Logan, Utah, conducted research on winter hardiness, persistence, and disease resistance in forage and pasture crops. In collaboration with the Agriculture and Agri-Food Canada and the University of Saskatchewan, orchardgrass and timothy plants with increased winter hardiness were identified and used to develop populations that are entering testing for potential cultivar release. Orchardgrass is an important crop in grass-seed growing regions of the U.S. However, Choke disease has reduced orchardgrass seed production up to 30% and is difficult because there are no effective fungicides or choke-resistant cultivars. In collaboration with ARS Corvallis, Oregon, scientists evaluated orchardgrass populations for choke prevalence and variation was identified. Two cycles of selection for plants with little or no choke infection were completed and are now being used to develop choke-resistant cultivars (new project). Scientists also developed a creeping rooted alfalfa germplasm with greater persistence under semi-arid rangelands grazing.
In support of Objective 2, to decrease the impact of invasive species and improve rangeland restoration, ARS researchers in Logan, Utah, released four improved varieties: AlkarXL tall wheatgrass, L-74X basin wildrye, Basin Utah sweetvetch, and Destination Snake River wheatgrass. L-74X basin wildrye had 167% more harvestable seed and 20% better seed germination than check cultivars and is being used to develop improved basin wildrye commercial varieties. Utah sweetvetch is a native rangeland legume that lacks a reliable seed supply due to the poor seed production by Timp, the only previous cultivar. Basin Utah sweetvetch was developed by selecting for improved seed set and reduced shatter resulting in double the seed production and greater forage mass than Timp. Snake River wheatgrass is a native grass widely used for restoration of rangelands impacted by weeds and wildfire. Destination Snake River wheatgrass was developed with increased seed yield (24 to 61% better), improved stand establishment (66% stand versus 34 and 12%, respectively), and greater biomass (50% more) than the common varieties.
Bluebunch wheatgrass is a priority native species for semi-arid rangeland restoration. However, it lacks the seedling establishment and persistence of non-native counterparts like crested wheatgrass. ARS researchers in Logan, Utah, developed genomic prediction models and completed one cycle of genomic selection on seed size, seed yield, and seedling establishment traits in bluebunch wheatgrass and carried this over into the new project. Salina wildrye is also a native grass in high demand that lacks ample seed production. Researchers repeatedly selected salina wildrye for seedling vigor, spike number, and seed retention, and the selected plants will be further evaluated (new project). Root development can determine the ability of young seedlings to establish and compete with invasive weeds. In a series of experiments with bottlebrush squirreltail and Sandberg’s bluegrass, rate of root development in relationship to water extraction was positively correlated with seedling establishment and competitive ability. Researchers also assessed the role of seedling density on water extraction rates when competing with invasive species and found that mixed-variety seedings of both grasses provided greater invasion resistance to annual weeds than single-variety seedings.
There is a paucity of native forbs available for rangeland restoration. ARS researchers in Logan, Utah, completed two cycles of selection in basalt milkvetch, a drought tolerant legume, for seed yield and will be releasing of an improved cultivar (new Project). ARS researchers found that Utah trefoil, also a native rangeland legume with poor establishment, exhibits both mechanical and physiological seed dormancy and were able to alleviate these dormancies by scarification and pre-chilling, respectively. However, seedling emergence in field trials was still low, suggesting additional limitations requiring further research (new Project).
In support of Objective 3, to improve nutritive value and forage productivity, ARS researchers in Logan, Utah, developed and released HighWest meadow bromegrass and USDA-Yeti orchardgrass. HighWest had 23% more forage growth, 6% greater protein and 22% more energy compared to other available cultivars making it an excellent grass for grazing. Orchardgrass is an important temperate perennial forage grasses but often suffers from winter injury and mortality. Therefore, researchers developed USDA-Yeti orchardgrass by selecting persistent plants growing at high elevations. USDA-Yeti combines excellent winterhardiness (10-30% less winter injury), improved stand establishment (12 to 16% greater), and greater forage mass (12-20% more) than other orchardgrass varieties.
Perennial plants enhance ecosystem services, and efforts to breed intermediate wheatgrass (IWG) as a dual-purpose forage and grain crop have demonstrated progress and commercial applications such as Kernza® grain, but its grain yields are significantly less than wheat. ARS scientists in Logan, Utah, cooperated with researchers from The Land Institute, Kansas State University, the University of Minnesota, and the U.S. Department of Energy to identify genes associated with grain production traits in IWG. They then developed genomic prediction models and completed one cycle of genomic selection in IWG for improved grain yield, seed size, seed retention, and seed threshing traits. The further development of IWG as a perennial grain (new project) will increase environmental sustainability of grain production on semi-arid croplands.
Forage-type perennial ryegrass plants were analyzed for gene expression, and 12 genomic markers and 32 expressed genes were found to be associated with higher digestibility. Orchardgrass breeding lines varying in water soluble carbohydrate (WSC) accumulation upon cold acclimation were identified. Gene expression differences between high and low WSC accumulating plants were characterized, and genes induced by cold temperatures found. This first characterization of expressed WSC genes is critical for gene-based selection in orchardgrass (new project).
In support of Objective 4, to develop reduced input turfgrass, ARS researchers in Logan, Utah, in collaboration with six other ARS locations and 10 universities, sequenced the DNA of nine major turf grasses, including Kentucky bluegrass, annual bluegrass, creeping bentgrass, colonial bentgrass, perennial ryegrass, annual ryegrass, hard fescue, bermudagrass, and centipedegrass. They identified sequences associated with drought, snow mold, and shade tolerance, and these sequences are under evaluation by ARS, universities, and private companies to identify genetic tolerance and resistance. This research has potential to fast-track the development of new resilient turf grasses and was carried into the new project. Evaluation of wheatgrass monocultures and mixtures was completed with results indicating that mixing wheatgrasses with Kentucky bluegrass resulted in better color, density, and coverage with approximately 50% less irrigation. Bermudagrass and zoysiagrass breeding lines were also characterized for growth and gene expression in near-freezing temperatures.
In support of Objective 5, to identify efficient grazing strategies, ARS researchers evaluated pastures mixtures of high-energy grass and legumes. Milk production from cows grazing pasture is up to 32% lower, mostly due to eating up to 30% less. ARS researchers in Logan, Utah, with Utah State University, determined how much young dairy cattle eat and grow when grazing four different grasses alone or in mixtures with the legume, birdsfoot trefoil. They found that the grass-birdsfoot trefoil mixtures increased the amount cattle ate by 34%, improved growth by 25%, and resulted in heifers being worth $166 more than those that ate grass alone.
Accomplishments
1. Release of ‘Basin’ Utah sweetvetch with improved seed and forage production. Legumes are important for rangeland restoration because they fix atmospheric nitrogen, enhance forage resources, and provide food for herbivores and pollinators. As such, Utah sweetvetch, a native, drought-tolerant, perennial legume, has received particular interest by land managers but reliable seed sources are limited and cost of seed is very high. Therefore, ARS researchers in Logan, Utah, in collaboration with the Utah Department of Wildlife Resources developed and released ‘Basin’ Utah sweetvetch by repeatedly selecting for improved seed set and reduced seed shattering. As a result, Basin has double the seed yield and greater forage mass (90% more) than Timp, the only previous cultivar of this species. Hence, this new and improved cultivar of Utah sweetvetch will benefit seed producers, help increase seed inventories and be a valuable resource to land managers as it facilitates improved rangeland restoration success.
2. Hard fescue genome reveals hidden genes to combat snow mold and improve shade tolerance. Hard fescue is a low-input turfgrass that requires little fertilizer and irrigation. However, it suffers from snow mold damage each winter season, and has relatively poor persistence in eastern shady regions of the U.S. Variation for snow mold resistance and shade persistence are unknown, as are genetic resources that can aid in the selection and breeding form improvement in these traits. ARS researchers in Logan, Utah, have sequenced the genome of hard fescue and used that reference genome to identify genes associated with snow mold resistance and persistence under shade. The genome sequence and genes are publicly available for national and international research and provide powerful new tools to help turfgrass breeders develop improved hard fescue varieties.
Review Publications
Peel, M., Walker, S., Waldron, B.L. 2024. Notice of release of ‘Basin’ Utah Sweetvetch. Native Plants Journal. 24(3):272-281. https://doi.org/10.3368/npj.24.3.272.
Xiao, H., Li, P., Monaco, T.A., Liu, Y., Rong, Y. 2023. Nitrogen and phosphorus additions alter foliar nutrient concentrations of dominant grass species and regulate primary productivity in an Inner Mongolian meadow steppe. Science of the Total Environment. 912. Article 168792. https://doi.org/10.1016/j.scitotenv.2023.168791.
Qi, F., Liang, S., Xing, P., Bao, Y., Wang, R., Li, X. 2023. Genome analysis of Thinopyrum intermedium and its potential progenitor species using Oligo-FISH. Plants. 12(21). Article 3705. https://doi.org/10.3390/plants12213705.
Peel, M., Anower, M., Wu, Y. 2023. Breeding efficiency for salt tolerance in alfalfa. Life. 13(11). Article 2188. https://doi.org/10.3390/life13112188.
Bailey, E., Thacker, E., Monaco, T.A., Veblen, K. 2024. Transplanted sagebrush “wildlings” exhibit higher survival than greenhouse-grown tubelings yet both recruit new plants. BMC Ecology and Evolution. 24. Article 50. https://doi.org/10.1186/s12862-024-02236-z.
Crain, J., Wagoner, P., Larson, S.R., DeHaan, L. 2024. Origin of current intermediate wheatgrass germplasm being developed for Kernza grain production. Genetic Resources and Crop Evolution. https://doi.org/10.1007/s10722-024-01952-1.
Bushman, B.S., Robbins, M.D., Qui, Y., Watkins, E., Hollman, A., Mihelich, N., Petrella, D., Breullin-Sessoms, F., Chou, M., Koch, P. 2023. Association of hard fescue (Festuca brevipila) stress tolerances with genome mapped markers. Crop Science. 64(2):1002–1014. https://doi.org/10.1002/csc2.21155.
Getz, M., Robbins, M.D., Thorsted, K., Jensen, K.B., Robins, J.G., Creech, E., Bushman, B.S. 2024. Late heading parental selection in orchardgrass (Dactylis glomerata L.). Crop Science. 64(2):1072-1082. https://doi.org/10.1002/csc2.21200.
Robins, J.G., Jensen, K.B., Buffham, J.R., Bushman, B.S., Heaton, K. 2023. ‘USDA-Yeti’ orchardgrass (Dactylis glomerata L.), a new orchardgrass cultivar that combines excellent winterhardiness and agronomic performance. Journal of Plant Registrations. 17(3):478-482. https://doi.org/10.1002/plr2.20304.
Feng, G., Xu, X., Liu, W., Hoa, F., Yang, Z., Nie, G., Huang, L., Peng, Y., Bushman, B.S., He, W., Zhang, X. 2023. Transcriptome profiling provides insights into the early development of tiller buds in high- and low-tillering orchardgrass genotypes. International Journal of Molecular Sciences. 24(22). Article 16370. https://doi.org/10.3390/ijms242216370.
Larsen, R., Robins, J.G., Jensen, K.B., Shapero, M., Striby, K., Althouse, L., George, M., Horney, M., Rao, D., Hernandez, A.J., Dahlgren, R., Bartolome, J. 2023. History and statistical considerations of using the 1-ft2 quadrat for monitoring peak standing crop and residual dry matter on California annual rangelands. Rangelands. 45(5):102-108. https://doi.org/10.1016/j.rala.2023.06.002.
Casler, M.D., Waldron, B.L. 2023. Endophytic fungal infection of meadow fescue in the driftless area of the upper Mississippi River Valley: Impacts on agronomic fitness. Grasses. https://doi.org/10.3390/grasses2040019.