Regeneration guidelines for small-grained cereals

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The information on this page was extracted from:
Payne T.S., Amri A., Humeid B. and Rukhkyan N. 2008. Regeneration guidelines: small-grained cereals. In: Dulloo M.E., Thormann I., Jorge M.A. and Hanson J., editors. Crop specific regeneration guidelines [CD-ROM]. CGIAR System-wide Genetic Resource Programme, Rome, Italy. 12 pp.

Before reading the regeneration details for this crop, read the general introduction that gives general guidelines to follow by clicking here.


Small-grained cereals include bread wheat (Triticum aestivum L.), spelt (T. spelta L.), durum wheat (T. durum Desf.), emmer (T. dicoccon Schrank), triticale (x Triticosecale spp.), barley (Hordeum vulgare L.) and oats (Avena sativa L.). These cereals are self-pollinated, annual, cool-season grasses that are grown for human food, animal feed and forage.
All of these species are found as both spring-and winter-planted types. Winter types require vernalization; cold tolerance is highest in wheat (down to -25°C), lower in barley (-20°C) and lowest in oats (-15°C). Accessions may be wild species, landraces, obsolete improved varieties, advanced improved varieties, breeding materials or genetic stocks and may be maintained as populations or as pure-breeding lines. Rye (Secale cereale L.) is excluded from this guideline because it requires specialized regeneration procedures due to its cross-pollinated reproductive nature.

Bread wheat (Triticum aestivum L.) landraces being characterized for drought tolerance, Obregon, Mexico (photo: Ana Maria Sanchez/CIMMYT)

Choice of environment and planting season

Planting season

Preparation for regeneration

Maintaining population integrity

When conserving and regenerating accessions that are populations of genetically diverse individuals, it is important to maintain adequate seed numbers (at least 500 viable seeds) to capture the full range of variation and genetic integrity, preventing the effects of genetic drift.

When to regenerate


Field selection and preparation

Using Jiffy pots for rescue regeneration of Barley and wild relatives (photo: ICARDA)

Barley regeneration plot (photo: ICARDA)

Artificial vernalization

Accessions with a strong vernalization requirement will require a refrigerated vernalization treatment if field conditions do not provide cool enough temperatures for long enough (<5°C for 6–8 weeks) to satisfy their vernalization requirements. Conduct the artificial vernalization treatment 8–10 weeks before the optimum field seed sowing date to allow transplanted seedlings optimal plant growth and development in the field.

Wild cereal species

Germination of wild species tends to be much more irregular than that of cultivated seed. The following measures are recommended to encourage germination of seeds of wild relatives:

NOTE: Wild species often have vernalization requirements.
NOTE: Seeds in lower florets will germinate first.
NOTE: Wild species often have day-length (long day) sensitivity and so require early planting.

Method of regeneration

Planting layout, density and distance

Wild red oat (Avena sterilis L.) plots separated by sunflowers to protect against wind (photo: Axel Diederichsen/Plant Gene Resources of Canada)

Sowing rate


Crop management

When in doubt, follow locally recommended best crop husbandry practices, including date and rate of planting, amounts and timing of fertilizer and supplementary irrigation applications, weed, disease and pest control, and time of harvest and post-harvest seed storage. The goal is to maintain accession integrity while producing ample quantities of highly viable, sound grain.

Weed management



Wild oat panicle in a glassine bag to prevent loss of seed (photo: Axel Diederichsen/Plant Gene Resources of Canada)

Clean the plot combine after use! (photo: ICARDA)

Pest and disease control

Roguing off-types

For accessions that are prone to shattering


Post-harvest management

Seed cleaning

Seed drying

Seed packaging

Germplasm seed health inspection

Common seed-borne pests and diseases

Storage conditions

Safety duplication

Monitoring accession identity

As materials are regenerated, conduct true-to-type verification using passport descriptors, comparative reference seed collections, minimum characterization traits, herbarium sheets and photo-documentation.

Documentation of information during regeneration

Collect the following information during regeneration, based on multi-crop passport descriptors (FAO/IPGRI 2001):

Standard methods and scale for the reporting descriptor traits can be found under the respective crop ‘List of Descriptors’ at:

References and further reading

Breese EL. 1989. Regeneration and multiplication of germplasm resources in seed genebanks: The scientific background. IBPGR, Rome, Italy.

Cook RJ, Veseth RJ. 1991. Wheat Health Management. APS Press, The American Phytopathological Society, St. Paul, MN, USA.

Engels JMM, Visser L, editors. 2003. A guide to effective management of germplasm collections. IPGRI Handbooks for Genebanks No. 6. IPGRI, Rome, Italy. Available in English (1.4 MB) and Spanish (1.5 MB).

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 .

FAO/IPGRI. 2001. Multi-Crop Passport Descriptors. FAO and IPGRI, Rome, Italy. Available in English, French and Spanish.

IBPGR. 1985. Oat descriptors. IBPGR, Rome, Italy.

IBPGR. 1985. Descriptors for wheat (Triticum spp.), revised. IBPGR, Rome, Italy. Available here

IPGRI. 1994. Descriptors for barley (Hordeum vulgare L.). IPGRI, Rome, Italy. Available here.

ISTA. 2008. International Rules for Seed Testing. ISTA Secretariat, Switzerland.

Lehmann ChO, Mansfeld R. 1957. Zur Technik der Sortimentserhaltung [On the technique for collection-maintenance]. Kulturpflanze 5:108–138.

Mathre DE, editor. 1997. Compendium of Barley Diseases, 2nd edition. APS Press, The American Phytopathological Society, St. Paul, MN, USA.

Mezzalama ML, Gilchrist L, McNab A. 2001. Seed health: rules and regulations for the safe movement of germplasm. CIMMY T, Mexico City, Mexico.

Wiese MV. 1987. Compendium of Wheat Diseases, 2nd edition. APS Press, The American Phytopathological Society, St. Paul, MN, USA.


The author wishes to acknowledge the inputs of Harold Bockelman, USDA Small Grains Collection, USA; Monica Mezzalama, International Maize and Wheat Improvement Center (CIMMY T) Seed Health Laboratory, Mexico; and Imke Thormann, Bioversity International, Italy. These guidelines have been peer reviewed by Axel Diederichsen, Plant Gene Resources of Canada; Christoph U. Germeier, Julius Kuehn Institute, Federal Research Centre for Cultivated Plants, Germany; Igor Loskutov, N.I. Vavilov Research Institute of Plant Industry (VIR), Russia; and Jan Valkoun, International Center for Agricultural Research in the Dry Areas (ICARDA), Syria (retired).

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.