SOP 6.1 Packaging & Storage for NPGS standard -18C backup, PVP, JPR, GMO (PDF)
SOP 6.5 Cryogenic Seed Storage (PDF)
SOP 12.2 Viability Testing (PDF)
SOP 12.4 Monitor Testing (PDF)
Seed in Base, PVP, or Plant Registration Collections
- Seed is received via U.S. Postal Service or an expedited mail service.
- Seed is placed at 5°C until unpackaged, logged in and inventoried (1-5 days).
- The moisture content of seed is adjusted at 5°C and 25% relative humidity for 3-4 weeks.
- Seed may be temporarily stored at -18°C for up to 4 months awaiting an initial viability assessment using standard germination tests.
- Seed quality is assessed through germination tests that use Association of Official Seed Analysts rules as a guideline.
- Germination procedures are specific to each species.
- Under most circumstances, four reps of 50 seed are scored for initial germination assessments.
- For seed considered for long-term liquid nitrogen storage, two of the four reps are exposed to liquid nitrogen for 24 hrs prior to germination.
- Germination data are entered into GRIN.
- The seed sample is weighed to determine seed number.
- The seed is packaged in a heat-sealable aluminum foil laminate bag.
- The package is labeled with bar code identity and location labels.
- Data on seed weight, seed number and storage location are entered into GRIN.
- The packaged seed is placed into NCGRP's -18°C storage vault or liquid nitrogen for long-term storage.
Seed for Safety Backup (black-box) Storage
Seeds receive above steps 1-2 and 9-11 (no data on seed weight or number) when the owner prepackaged the seed in foil-laminate bags. Seeds receive additional steps 3 and 8 if moisture adjustment and moisture proof packaging were not provided by the owner.