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ARS Home » Pacific West Area » Logan, Utah » Forage and Range Research » Research » Research Project #435977

Research Project: Improved Plant Genetic Resources and Methodologies for Rangelands, Pastures, and Turf Landscapes in the Semiarid Western U.S.

Location: Forage and Range Research

Project Number: 2080-21000-018-00-D
Project Type: In-House Appropriated

Start Date: Feb 4, 2019
End Date: Feb 3, 2024

Objective:
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.