Crop Genebank Knowledge Base

Safety duplication

Safety duplication of cultivated rice, wild rice and related genera genetic resources

Contributors to this page: T.T. Chang Genetic Resources Centre-IRRI, Los Baños, Philippines (Ruaraidh Sackville Hamilton, Ken McNally, Flora de Guzman, Renato Reaño, Soccie Almazan, Adelaida Alcantara, Elizabeth Naredo); WARDA, Cotonou, Benin (Ines Sánchez); UPLB-University of the Philippines, Los Baños (Teresita Borromeo).

	IRRI ships 35.5 million seeds to Svalbard

	After months of preparation by staff of the Genetic Resources Center at IRRI, a replicate set of the Global Rice Collection from 123 countries held by IRRI left for the Svalbard Global Seed Vault or 'Doomsday Vault'. IRRI is contributing the largest number of accessions for a crop (70 180) and the largest estimated number of seeds (35 577 576). The video shows GRC staff members preparing and loading seed containers. Click to see the video on YouTube.

When should it be used

A safety back up should be kept of all unique accessions, under ideal conditions for secure long-term conservation, at least as good as the base collection.
The safety back up should always be in a distant high-quality genebank, preferably in a different continent from the active and base collections (ensuring that the safety back up is subject to different risks minimizes the risk of simultaneous loss of safety back up, base and active collections).

Current best practices are for two levels of safety backup:

A primary back up in a high-quality genebank chosen by the genebank holding the active collection (see general page on safety duplication for more details).
A second, 'ultimate' back up in the Svalbard Global Seed Vault (click here and here for details).

The ideal safety backup is a 'black box', remaining legally under the administration of the genebank providing the samples, not the genebank holding the safety back up.
As black-box conservation in a remote genebank, seed packets should be packed into strong, secure, sealed boxes for shipment and should remain in the same boxes for storage in the remote store.
Samples conserved in the safety back up collection should never be used, even for viability testing, except to restore samples in the event of the accidental loss of all samples in the active and base collections.
Since the back up samples should not be used for testing viability, special consideration should be given to the need for monitoring viability in the safety back up collection.
If the conditions of the backup storage are indubitably as good as or better than those of the base collection, there should be no separate viability monitoring schedule for the safety duplicate; monitoring viability in the base collection is used as a surrogate. However, if there is any doubt, additional samples should be deposited in the same location as the safety back up specifically to provide seed for viability testing.

Sample specifications

Minimum sample size for storage

15 g (enough for one planting) (see also general page on safety duplication).

Viability for storage

85% of initial viability.

Moisture content

6-7%.

Container specifications

Seed packaging method

Preparing seed packets

Routine preparation of samples for safety back up should be undertaken at the same time and in the same place as for the base collection.
Separate preparation of the safety back up is needed only in the case that a base collection has been established without arranging for safety duplication.
Use a specially designated seed packing, labelling and weighing room, situated adjacent to the seed drying room and with humidity reduced using a dehumidifier.
Prepare two small high-grade aluminium foil pouches per accession (one for the primary back up, one for Svalbard).
Prepare barcoded labels for each packet, with the following printed information: accession number, name, crop year, Seed Lot ID, and barcode. The barcode itself should contain the Seed Lot ID.
Prepare small paper labels with accession ID and crop year to be placed inside the packets.
Label the pouches inside and outside, and arrange them in the packing area in the same order in which they will be withdrawn from the drying room.
Take only a few samples at a time from the drying room.
For each sample, find its corresponding labelled pouches and double check that all labels match.
Pour at least 100 grains of seed into each pouch and seal using a high temperature constant heat sealer with 1 cm seal width.
Place in temporary storage until sufficient samples have accumulated for shipping to the safety back up location.

Preparing containers for seed packets, to pack final container for shipping and storage

Packing in parallel with the base collection improves efficiency and ensures that safety back up is a routine element of conservation.
Label the container with a unique container ID.
Sort foil pouches by expected date of replacement: divide them into groups by expected longevity and sort within groups by year of seed production.
Divide the box into compartments with thin cardboard dividers, each compartment 10 cm wide x 12 cm tall x the length of the box (packing foil pouches into fixed rows 1 pouch wide and 1 pouch tall keeps them in place).
Pack pouches tightly within each compartment, alternating pouches high and low (tight packing prevents dislodgment during transit; alternating high/low positions enables tighter packing given the central bulge of seed in each packet).
Prepare box inventory with ID and layer of each accession in the box.
Place printed copy of the inventory in the box.
Seal the box for shipment.

Specifications of packaging material

Seed packets

High grade laminated aluminium foil with wide seam on all sides, 12 cm x 9 cm.
To ensure suitability for long-term conservation, use special-purpose pouches designed in consultation between the Global Crop Diversity Trust and the manufacturers – the specification is higher than for the pouches used for the active collection.
Special-purpose high-quality labels created with material, adhesive and print designed to survive 100 years at 0-100% humidity and -20°C to +30°C, e.g. from CILS International.

Shipping/storage containers

The containers must be strong enough to endure shipping, able to withstand extremes of temperature and moisture, of a size convenient for handling and storage.
More detailed specifications are available from the Nordic Genetic Resource Centre for boxes destined for storage in the Arctic Seed Vault in Svalbard (click here).

Storage specifications

Assigning location codes in boxes

Depending on the selected size, each box will have packets arranged probably in two layers of three long rows.
Record the layer in which each accession is to be found (since packets are packed in order shown in the packed printer inventory, it is sufficient to record just the layer within the box occupied by each accession, without further information on where it is within the layer).

Storage conditions

-18 to -20^oC.

Shipping method

Airfreight with temperature logger.

Legal arrangements

Ensure there is a legal contract (typically a Letter of Agreement or similar) between the two parties concerned, detailing the rights and obligations of each party.
Special agreement for Svalbard.

All shipments must be accompanied by

Export permit (if required by the exporting country).
Import permit (if required by the importing country).
Customs declaration (if required by the importing country).
GMO declaration (if required by the importing country).
Phytosanitary certificate (if required by the importing country and no waiver is granted).

Recording information during safety duplication

The following information should be recorded for each step:

Accession ID (ID of accession).
Seed lot ID (ID of this sample of the accession).
Crop season (year and season the seed was harvested).
Storage type (primary safety backup, secondary safety backup, type of storage and packing for this sample).
Location in storage (box and layer number).
Date shipped (date when the sample was shipped to genebank holding safety backup collection).
Species.
Germination % (2 replications) (germination % - separate values for each replication; new record for each test).
Germination test N (number of seed per replicate used for testing germination %).
Germination date (date of germination test; new record for each test).
Seed amount units – grams, number of packets (units used to record the amount of seed of this sample).
Seed amount (amount of seed in store; new record for each update).
Inventory date (date the amount was last updated; new record for each update).

References and further reading

Agreement between (Depositor) and the Royal Norwegian Ministry of Agriculture and Food Concerning the Deposit of Seeds in the Svalbard Global Seed Vault. Available [online] from: http://www.nordgen.org/sgsv/scope/sgsv/files/SGSV_Deposit_Agreement.pdf. Date accessed: 10 July 2013.