Crop Genebank Knowledge Base

Field bank

Field bank for 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 at Los Baños (Teresita Borromeo).

When are field banks (in vivo collections) used

For wild rice species or related genera that produce recalcitrant seed or no seed.
- This is the case of O. longistaminata, O. neocaledonica, O. granulalta, O. meyeriana and related genera such as Leersia at IRRI, that do not produce enough seeds for storage.
- Porteresia coarctata has recalcitrant seeds.
When wild rice or related genera do not flower in genebank conditions.
- This is the case of O. schlechteri and related genera such as Potamophila and Zizaniopsis at IRRI.
When wild rice relatives have special needs, where different species require different cultural practices.
- Oryza granulata and Oryza meyeriana for example, need partial shading and special soils, because they are originally from forest regions, whereas most of the other species need to be kept soaked because they are originally from swampy areas.

There are more than 20 different species of wild rice scattered across tropical Asia, Africa, Latin America and the Caribbean that need to be well conserved. These species are from a rich pool of diversity from different habitats, from sunny open lands to shady forests.

At the IRRI genebank there are more than 3000 potted wild rice specimens being conserved in a large screen house as living plants.

Establishment of field genebanks (in vivo collections)

Perennial species should be maintained as living plants when seeds are difficult to produce.
Plants must only be grown inside contained facilities (e.g. glasshouse or screen house), in compliance with national biosafety regulations, to prevent their escape as a weed.

Routine monitoring for field (in vivo) collection

Methods and frequency

Survival rates - check survival monthly (some germplasm that has to be maintained in an in vivo collection is perennial and regular monitoring is important to ensure survival).
Vigour - record vigour monthly.
Pests and diseases - inspect for pests and diseases monthly (this is sufficient to identify any pests or diseases and rescue the plants if problems arise).
Replacement by other weeds - rogue plants of other species regularly and at flowering time. Check taxonomy at least once in a year.

Recording information for field (in vivo) collections

The following information should be recorded for each step:

Accession number (an ID number).
Genus (genus name of the plant, entered in full).
Species (species name of the plant, entered in full).
In vivo site name (a code to indicate the site of seed production).
Plot number (the plot number at the production site).
Date of monitoring (date when data is collected).
Name of staff (name of staff recording the data).
Damage [a score of 1-5 (where 5 is badly damaged) on amount of damage (specify if from insect, disease etc)].
Vigour [assessment of vigour of the plants on a scale of 1-5 (where 5 is high)].
Details of plants removed or destroyed (due to type mixtures or pests or disease contamination).

References and further reading

International Rice GeneBank Operations Manual. Available here.

Rice Knowledge Bank. Homepage [online]. Available from: http://www.knowledgebank.irri.org/. Date accessed: 15 July 2013.