Filters

Viability of bread wheat, durum wheat, triticale and related cereals genetic resources

Contributors to this page: CIMMYT – Wheat, Mexico (Thomas Payne) and ICARDA, Syria (Ahmed Amri) with inputs also received from CIMMYT – Maize, Mexico (Suketoshi Taba); USDA – National Small Grains Collection, Aberdeen, Idaho, USA (Harold Bockelmann); CGN, Wageningen, The Netherlands (website) and IPK, Gatersleben, Germany (Helmut Knűpffer).

Contents:
Viablility testing
Routine monitoring

Viability testing

Laboratory methods

Describes the various recommended options, to test the viability and quality of wheat seeds. The percentage of germination of the stored seeds of the accessions determines when the regeneration of the accessions should take place and if the accession can be distributed to the users.

Type of test

Number of seeds and replicates

Pre-treatment

Media

Temperature

Light

Duration of test

Monitoring intervals

To ensure the viability of the seed accessions in both base and active collection.

Below four different approaches to viability monitoring intervals are given. They are all valid, but the USDA approach seems to be the most innovative!

ICARDA

CIMMYT

USDA National Small Grains Collection

Viability Status

Inventory Status*

High

Low

Critically Low

High (>70%)

9

8

5

Low (20-70%)

7

6

3

Critically Low (<20%)

4

2

1

*High = >50 g for cultivated species, >10 g for wild species.
Low = 15-50 g for cultivated species, 4-10 g for wild species.
Critically Low = <15 g for cultivated species, <4 g for wild species.

CGN Wageningen

Recording information during viability testing

The following information should be recorded for each processing step:

Normal germinated seeds of Wheat (photo: ICARDA)

On the petri dishes

On the data sheets and database

Back to top


Routine monitoring

The genebank curator must continually monitor the general conditions of the genebank infrastructure and operating procedures to ensure that conserved seed quantity and seed viability is maintained to international standards. Safety from vandalism, robbery, adverse weather, electrical failure and lack of off-site safety duplication must all be considered when reviewing the security of a collection.

Monitoring frequency

Describes the minimum quantity and minimum viability of seeds below which they need to be regenerated.

Critical quantity

Critical germination level

Recording information during routine monitoring

The following information should be recorded for each step:

References and further reading

AOSA (Association of Official Seed Analysts). 2005. Page 113 in: Rules for Testing Seeds (Capashew Ed.), 4-0, 4-11. Las Cruces, New Mexico.

Ellis RH, Hong TD, Roberts EH. 1985. Handbook of seed technology for genebanks volume I. Principles and methodology. Handbooks for Genebanks no. 2. International Board for Plant Genetic Resources, Rome, Italy.

ISTA. 2005. International rules for seed testing. ISTA Secretariat, Switzerland.

ISTA. 2003. International rules for seed testing. ISTA Secretariat, Switzerland.

Walters C, Wheeler LM, Grotenhuis JM. 2005. Longevity of seeds stored in a genebank: species characteristics. Seed Science Research 15:1-20.

Back to top

The Genebanks

The 11 CGIAR genebanks currently conserve 730,000 of cereals and grain legumes, forage crops, tree species, root and tuber crops, bananas and crop wild relatives.

close-icon