The U.S. National Plant Germplasm System (NPGS) is a cooperative effort by U.S. state and federal government and private organizations to preserve the genetic diversity of plants.
The NPGS aids scientists and the need for genetic diversity by acquiring, preserving, evaluating, documenting and distributing crop germplasm.
Since many important crop species originate outside the United States, the first steps toward diversity are acquisition and introduction. New germplasm (accessions) enter NPGS through collection, donation by foreign cooperators or international germplasm collections. An identifying number such as the Plant Introduction number (PI number) is assigned to each accession. The accession is then evaluated, maintained, and made available for distribution.
Through these efforts, NPGS assists in improving the quality and productivity of crops. The GRIN database is managed by the Database Management Unit, while the acquisition of plants is managed by the Plant Exchange Office.