Crop Genebank Knowledge Base

Safety duplication

Safety duplication of radish genetic resources

Contributors to this page: CAAS, China (Qiu Yang, Li Xixiang); Bioversity International, Italy (Imke Thormann, Ehsan Dulloo); CGN, Netherlands (Noortje Bas); IPK, Germany (Andreas Börner, Ulrike Lohwasser); AVRDC, Taiwan (Andreas Ebert); USDA, USA (Larry Robertson); NBPGR, India (Chitra Pandey); SASA, UK (George Campbell); University of Warwick, UK (Charlotte Allender).

When should it be used

Always. See also the general page on safety duplication procedures.
Integrating the accessions into the other genebank collections is preferred over the black box safety duplicates.
In case of integration of safety duplicates, the recipient genebank will need to register the accessions.
Black box safety duplicates should ensure both seed viability and seed quality.

Sample specifications

Minimum sample size for storage

The minimum samples size for storage should include sufficient seed for 2 regeneration cycles. Examles for samples sizes in genebanks:
- AVRDC: 2 x 200 seeds each duplicated at an active genebank and at SGSV, Norway.
- CAAS: 60g
- CGN: 600 seeds, considered sufficient for 2 regenerations.
- IPK: 10-15 g (1000-2500 seeds) each of cultivated material and 8-12 g (1000-2000 seeds each of wild material to comprise a quantity for two regeneration cycles of 300-400 seeds per cycle).
- SASA: 10% of active sample. This is considered a representative and consistent proportion of the overall sample and will not compromise the active sample in the way that a fixed size could.
- USDA: 2000 seeds. Based on radish being cross-pollinated crop and the need to maintain maximum number of genes, this provides for 10 standard field regeneration attempts.
- WARGRU: 10g

Viability for storage

Not less than 80-85% viability for cultivated radish .
A minimum of 60% viability for the wild relatives.

Moisture content

At 3-7% (according to FAO/IPGRI standards).

Container specifications

Seed packaging method

Aluminum foil packets sealed hermetically under light vacuum conditions with a heat sealer. Vacuum should be used with caution as it can damage seeds.
Packing is best carried out in an air-conditioned room with controlled humidity as quick as possible after drying.

Specifications of packaging material

Three layered standard aluminum foil packets consisting of the following layers:
- Polyester 17g/m2 (12 μm) (outer)
- Alufoil 33g/m2 (12 μm) (middle)
- Polyethylene 63g/m2 (80 μm) (inner)

Storage specifications

Assigning location codes

Boxes are numbered and lists of seeds per box maintained in a database.
Use a barcode system.

Storage conditions

-18 ± 3°C.

Shipping method

Should be safe and fast enough to avoid delays and deterioration of seed quality during transfer.

Legal arrangements

The documentation listed below should be included to facilitate custom clearance:

GMO declaration (if issued).
Standard agreement for safety duplication.
Special agreement for Svalbard.
Phytosanitary certificate.
Certificate of origin.
Certificate of no-commercial value.
Electronic and/or hard copy of associated passport information.

Recording information during safety duplication

The following information should be recorded for each step:

Accession number (unique number).
Flag of safety duplicated (Y/N).
Number of seeds.
Weight of seeds.
Year of production of seeds.
Year of safety duplication.
Name of institute holding the safety duplicates.
Box label where the sample is placed.
Common steps (regardless of conservation strategy).

References and further reading

Engels JMM, Visser L, editors. 2003. A guide to effective management of germplasm collections. IPGRI Handbooks for Genebanks No. 6. IPGRI, Rome, Italy. Available here.

FAO/IPGRI. 1994. Genebank standards. Food and Agriculture Organization of the United Nations, Rome and International Plant Genetic Resources Institute, Rome. Available in English, Spanish, French and Arabic .

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