Notice of release of Destination Germplasm of Snake River wheatgrass

Authors: Jones, Thomas; Larson, Steven; Monaco, Thomas; Rigby, Craig; Forsyth, Kyle

Submitted to: Native Plants Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/25/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Snake River wheatgrass is widely used for restoration of rangelands in the Intermountain West, but its use and efficacy have been limited by poor establishment in the case of ‘Secar’ and low seed yields in the case of ‘Discovery.’ The recently released germplasm, Destination was developed directly from Discovery by recurrent selection for emergence from deep seeding in the greenhouse and numbers of seedheads in the field. Destination features greater biomass, seed yield, and seed mass than Discovery (and Secar) by 24.4% (41.0%), 78.3% (43.7%), and 16.1% (25.5%), respectively. Increased seed mass was highly correlated with greater stand establishment in the establishment year. Calculations indicated that, when planted on an equal seed-weight basis, Destination’s establishment would be greater than establishment of Discovery and Secar by 66.6% and 355.4%, respectively. Thus, Destination is a Snake River wheatgrass germplasm that should be more effective than the two previous cultivars.

Technical Abstract: Native grasses are widely used for restoration of rangelands in the Intermountain West that have been negatively impacted by exotic weedy annuals and frequent wildfire. However, their use and efficacy are typically limited by low seed yields and poor establishment. To address these limitations, Destination Germplasm Snake River wheatgrass (Elymus wawawaiensis J. Carlson & Barkw.) was released by USDA-ARS on 31 May 2023 for restoration and conservation of semiarid rangelands in the northwestern US. Destination was developed directly from the E-21 population, which was released in 2007 as ‘Discovery.’ Destination was selected for emergence from deep seeding in the greenhouse, a generally recognized technique to improve seedling vigor, and spike number in the field. Aboveground biomass, seed yield, and seed mass were measured at North Park Fam (Hyde Park, UT). For establishment-year (2021) biomass, Destination exceeded Secar by 118.1% and Discovery by 51.3%. Across the two seed-production years (2022-2023), Destination’s biomass (and seed yield) exceeded Secar’s by 41.0% (43.7%) and Discovery’s by 24.4% (and 78.3%). Likewise for seed mass, Destination exceeded Secar by 25.5% and Discovery by 16.1%. When sown at Nephi, UT on an equal seed-mass basis, 2023 stand establishment was 65.8%, 34.0%, and 11.5% for Destination, Discovery, and Secar, respectively. This calculates to a 66.6% increase in establishment for Destination relative to Discovery when sown on an equal seed-weight basis. A strong positive correlation (r2 = 0.958) was found between seed mass at North Park and establishment percentage at Nephi. Thus, selection for spike number increased seed yield and production-year biomass, and selection for deep-seeding emergence increased seed mass, stand establishment, and establishment-year biomass. Hence, the use of Destination should facilitate improved restoration success relative to its predecessors, Secar and Discovery.