The Plant Germplasm Introduction And Testing Research Station, otherwise known as the Western Regional Plant Introduction Station (WRPIS), is one of the four Plant Introduction Stations in the USDA-ARS National Plant Germplasm System with the responsibility of maintaining seed and clonal germplasm. WRPIS was established in 1952 with the initial mission to acquire new plant germplasm and establish a maintenance program. Subsequently, germplasm conservation and research programs developed in the disciplines of horticulture, agronomy, genetics, plant pathology, and entomology. The current mission of the station is to acquire, maintain, evaluate, document and distribute the germplasm of over 2,600 plant species from 376 genera.

There are currently nine scientists in this Unit, and they have had extensive experience in addressing the objectives listed. Primary facilities are located on the campus of Washington State University in Pullman, WA. Sister programs that are part of the WRPIS include the National Temperate Forage Legume Genetic Resources Unit in Prosser, Washington, and the National Arid Land Plant Genetic Resources Unit in Parlier, California. These additional locations provide diverse growing conditions amenable to the production of high quality seed of a wide range of plant germplasm. Each site has primary responsibility for the appropriate genera, plus the Parlier site is also responsible for providing an alternate site for increase of germplasm from other NPGS sites.

New developments in the preservation of plant biological diversity at WRPIS include the added responsibility of preserving special genetic stocks collections and developing core subsets of the larger collections.