Seed Cleaning

Samples are prepared for safety duplication in the same way as the base collection: • Seeds should be dried to a moisture content of 5±2% depending on species. • Seeds should be clean and healthy. • Percent germination should be greater than 85%. • Seeds should be hermetically sealed in appropriate containers. Sample size can be smaller, but it should be sufficient to conduct at least three regenerations (with the safety factor built in). To save time, samples for safety duplication ( Seed Processing, Seed Cleaning, Stone separator, Combo Cleaner, Grading Machine, Gravity Separator  )

may be prepared simultaneously when processing seeds for base collection. Specific agreements should be made with the recipient institute for holding the duplicate of a collection. Ideally, duplicate collections should be held in the same conditions as base collections to ensure long-term survival, although several types of duplication are recognized:

 • Black box: when the sole responsibility of the recipient genebank is to maintain the duplicates without handling them. Beyond providing the best possible storage conditions, the recipient institute has no further responsibility for the samples. It is the originator‘s responsibility to establish a viability monitoring scheme and regenerate the collection when necessary. If the storage conditions for the backup collection are the same as for base collection, loss of viability can be predicted from the results of base collection-monitoring. Following regeneration of the sample in the base collection, the originator also replaces the safety duplicate. For black-box duplication outside the country, special permission is required to export ( Seed Processing, Seed Cleaning, Stone separator, Combo Cleaner, Grading Machine, Gravity Separator  )

seeds without phytosanitary certificates from the originating country. Similarly, the phytosanitary authority in the destination country must permit the recipient to import seeds without the routine quarantine examination. • Base: maintained under suitable condition for long-term storage and incorporated into the recipient collection. • Active: when the duplicate collection is incorporated into the recipient’s collection, and is therefore subject to regeneration, multiplication and distribution by the recipient. 95 Manual of Seed Handling Archive collection Genebanks may choose to store germplasm samples that do not need to be represented in a base collection or distributed as an ‘archive collection’. These samples are maintained under optimal conditions for long-term survival but with no further investment in monitoring and regeneration. Germplasm included to archive ( Seed Processing, Seed Cleaning, Stone separator, Combo Cleaner, Grading Machine, Gravity Separator  )

collection can be: • experimental lines bound by intellectual property (IP) rights— samples can be held as black-box collections and returned upon request to the IP holder; • germplasm that lies outside the genebank mandate—samples can be stored temporarily until another genebank with a relevant mandate is identified; • accessions identified as duplicates following rationalization of an existing base collection; and • accessions no longer needed in the collection following a reassessment of the genebank’s mandate or material disbanded due to lack of funding. Documentation Proper documentation of seed packaging and storage procedures allows rapid accession of new samples; response to queries regarding conserved germplasm; and monitoring of ( Seed Processing, Seed Cleaning, Stone separator, Combo Cleaner, Grading Machine, Gravity Separator  )

the quality and quantity of stored material to carry out regeneration and distribution. Suggested descriptors include the following: • Storage conditions/collection type • Type of container, if this varies in the genebank • Number of containers • Total amount of seeds stored (by weight or number) • Date of storage • Location in genebank • Minimum amount of seed allowed (base unit) for dissemination/ regeneration • Location of safety duplicate, if available Further reading Cromarty A.S, Ellis, R.H. and Roberts, E.H. 1982. The design of seed storage facilities for genetic conservation. ( Seed Processing, Seed Cleaning, Stone separator, Combo Cleaner, Grading Machine, Gravity Separator  )

IBPGR, Rome. Engels, J.M. and Visser, L. (eds.). 2003. A guide to effective management of germplasm collections.