Notice of Release of Destination Germplasm of Snake River Wheatgrass

Abstract

Native grasses are widely used in the Intermountain West for restoration and conservation of semi-arid rangelands negatively impacted by exotic weedy annuals and recurrent wildfire. Their utilization, however, is typically limited by low seed yields and poor establishment. To address this, Destination Germplasm Snake River wheatgrass (Elymus wawawaiensis J. Carlson & Barkworth [Poaceae]) was released by USDA ARS on 31 May 2023. Destination Germplasm was developed directly from ‘Discovery’, released in 2007, being selected for emergence from deep seeding in the greenhouse, which is a generally recognized technique to improve seedling vigor and spike numbers in the field. Establishment-year (2021) biomass of Destination Germplasm exceeded ‘Secar’ by 118.1% and Discovery by 51.3% at North Park Farm (Hyde Park, Utah). Across 2 seed-production years (2022–2023), Destination Germplasm biomass and seed yield exceeded Secar by 41.0% and 43.7%, respectively, and Discovery by 24.4% and 78.3%, respectively. Likewise, for seed mass, Destination Germplasm exceeded Secar by 25.5% and Discovery by 16.1%. When fall-seeded at Nephi, Utah, in 2022 on an equal seed-number basis, 2023 stand establishment was 65.8%, 34.0%, and 11.5% for Destination Germplasm, Discovery, and Secar, respectively. This calculates to a 93.5% and 66.6% increase in establishment for Destination Germplasm relative to Discovery when sown on an equal seed-number and an equal mass basis, respectively. A strong positive correlation (r² = 0.958) was found between seed mass at North Park and establishment percentage at Nephi. Destination Germplasm will facilitate improved establishment and seed-production success relative to its predecessors, Secar and Discovery.