Crop Genebank Knowledge Base

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  • Banana ( 0 )

    Importance and origin

    Banana (Musa spp.) is one of the most ancient fruit crops known and used by man. It originated in South-East Asia and was first domesticated some 7000 years ago. Today it is grown in every humid tropical and many sub-tropical regions. It is the fourth most valuable food crop after rice, wheat and maize. The fruit crop provides a staple food source for 400 million people, most important in East–Africa. About 95 million metric tons of bananas are harvested annually around the world, 30% of these being plantains. About 90% of the total production takes place on small-scale farms and it is used for home consumption or in domestic markets. The remaining 10% (dessert bananas) are mostly produced in Latin-America and Caribbean and commercialized in world trade.

    Production of banana in the world



    How is it consumed?

    For many people in the tropics, bananas are an essential component in their daily diet.
    The fruits, parthenocarpically produced, are eaten raw, cooked, brewed into and alcoholic beverage or processed into chips.
    The leaves are used for wrapping food, the terminal bud of the inflorescence is cooked as a vegetable, fibers are used for ropes and corm tissue (Ensete spp.) fermented.

    Bananas are essential for many people in the tropics



    Which types exist?

    Bananas evolved from inter-and intraspecific hybridization between two diploid wild species of the genus Musa, sp. acuminata (AA) and sp. balbisiana (BB), the only species that set seeds. These crosses produced edible cultivars (all female sterile with various levels of male sterility) currently cultivated, with the following genomic configuration:
    Diploids AA and AB (less cultivated)
    Triploids AAA, AAB and ABB (most widely cultivated)
    Tetraploids AAAA, AAAB, AABB and ABBB (very rare)

    Most well known types are plantains (AAB) used for cooking and dessert bananas (AAA Cavendish type).



    Further reading:

    Simmonds and Shepherd, 1955
    FAO, 1995
    Denham et al., 2003
    De Langhe, 1995
    INIBAP, 2004
    INIBAP, 2005


    • main ( 2 )
    • Registration of Musa ( 1 )

      Registration and information systems - Importance and uses

      Registration is the first step after acquisition of a sample in any genebank. Collections in genebanks are the genetic base for current and future breeding programs and a source of safety material for distribution to researchers and other users. It is essential that samples are all properly documented from the moment they enter a genebank as well as through all subsequent genebank operations.
      A step by step guideline can be seen by clicking here.

      How should it be done?

      Information systems
      An information management system must be created in each genebank. This database must be searchable by the genebank curators and staff for specific information through a range of queries.

      Numbering and labelling systems
      Consecutive alpha numeric or numeric codes must be used for each new accession acquired. This code must be linked to all subsequent information about this sample: passport data, designation status and taxonomic information. The information system must keep a record of genebank operation data, including storage location, stocks, monitoring, health tests and the distribution status. The same system must also manage germplasm orders, shipment related information and files genebanks ‘contacts’ information.
      Bar-coding is a useful tool that can compliment a genebank information system.

      Extra samples
      A separate subset of materials should be kept after registration to be regenerated under greenhouse conditions for harvesting leaf samples that can be processed for DNA/lyophilized leaf bank. These banked leaf materials can serve as a voucher for the germplasm stored in the active and base collections and samples can be made available to users for research in gene discovery and function, marker development and detailed genotypic characterisation. Method to be detailed by INIBAP


      Musa Germplasm Information Systems (MGIS)

      In 1997, INIBAP laid the basis for a global information system for Musa through the release of MGIS. The aim of the system was to enhance knowledge on Musa diversity, to help rationalizing conservation and to improve the use of banana genetic resources though a facilitated access to comprehensive information.
      In 2005, the MGIS database contained key information, including passport data, botanical classification, morpho-taxonomic descriptors and characteristics such as agronomic traits, disease resistance, stress tolerance, biochemical or molecular genetic markers, and plant photographs as well as GIS information on 5188 accessions managed in 18 banana collections (link to the list of collections) around the world making it the most extensive source of information on banana genetic resources.
      The database is publicly accessible through the internet at MGIS homepage.htm or at This global database can be queried on the identity, origin, characteristics and distribution of the individual accessions in the collections. This allows curators of the participant institutions worldwide to share and compare their data. The database is also particularly helpful for various germplasm users namely breeders, researchers and farmer communities, in locating alternative sources of banana germplasm and identifying the most appropriate accessions with particular traits of interest.

      Homepage of the MGIS website (click on the picture if you wish to go there now)


      Further reading:

      Van den houwe et al., 2005 (The management of banana (Musa spp.) genetic resources at the IPGRI/INIBAP gene bank: the conservation and documentation status

      Calles et al., 2003 (Best Practices for Genebank Management)


    • Conservation of musa ( 4 )



    • In vitro bank for banana ( 4 )
    • Cryopreservation for musa ( 3 )
    • In the field for musa ( 3 )
    • Safety duplication of musa ( 1 )

      No. of samples (tubes) per line or cultivar

      Size of container

      Kind of medium

      Amount of medium

      Placement of label
      Bioversity - written directly on cryotubes using pencil
      IITA - higher half

      Labeling material
      Bioversity - not applicable
      IITA - marker on parafilm for tubes, tape on polyethylene bags

      Label information
      Bioversity - accession ID, freezing date, experiment number
      IITA - accession number, line number and date of last introduction

      Viability testing
      Conditions or timing when the test is conducted
      After being one hour in liquid nitrogen

      No. of samples for testing
      Bioversity - 3 cryotubes per accession (experiment)
      IITA – 1-5 seedlings

      Criterion for long-term storage
      At least 95% certainty that a minimum of 1 plant can be regenerated per experiment


      Type of container
      Bioversity - dry shipper
      IITA – plastic boxes

      Method and duration
      Bioversity - Air courier or hand carried
      IITA - car (4x4) 5 to 6 hours drive

      Bioversity - Frozen in liquid nitrogen
      IITA - ambient

      Frequency of shipment
      Bioversity - Initially 3 to 4 x a year; once a year thereafter
      IITA – 3 to 4 months

      Genebank for safety storage
      Bioversity - IRD, France & KULeuven, Belgium
      IITA - IITA Cotonou, Benin

      Type of storage
      Bioversity – Cryopreservation in liquid nitrogen tank
      IITA – Tissue culture slow growth

      Type of container
      Bioversity - 2mL cryotubes
      IITA - Polyethylene bags (13 x 1.3 cm)

      Temperature (in degrees Celcius)
      Bioversity – (-196 oC)
      IITA – 18

      Life expectancy of clones
      Bioversity - Indefinite
      IITA – 4-6 months

      Back-up generator
      Bioversity - none
      IITA - none

      Other features
      Availability of liquid nitrogen alarm system


      Data arrangements
      Bioversity - Germplasm ID, inventory of box content sent with samples
      IITA - mport permit stating list of accession transferred, endorsed by PQS prior to departure Report at boarder PQS office
      Provision for replacement of germplasm
      Bioversity - If less than 95% certainty that one minimum plant can be regenerated per experiment


      Provision for return of germplasm
      Bioversity - Loss of samples from LTS at Bioversity ITC; sample provided by the duplication site on Bioversity's requests on a 6 month written notice
      IITA - Repatriation permit to ask when needed

  • Barley ( 0 )
  • Cassava ( 0 )


    The importance and origin of Cassava

    Cassava (Manihot esculenta Crantz) is a perennial woody shrub with an edible root, which grows in tropical and subtropical areas of the world. It is also called yuca, manioc, and mandioca. Cassava has the ability to grow on marginal lands where cereals and other crops do not grow well; it can tolerate drought and can grow in low-nutrient soils. Because cassava roots can be stored in the ground for up to 24 months, and some varieties for up to 36 months, harvest may be delayed until market, processing, or other conditions are favourable.
    It has been cultivated in tropical America for more than 5 000 years. It was introduced to Africa and Asia by Portuguese traders during the 16th century; it is now grown in over 90 countries and provides food and a livelihood for 500 million people in the developing world.



    How is it consumed?

    Cassava is the basis of many products, including food. In Africa and Latin America, cassava is mostly used for human consumption, while in Asia and parts of Latin America it is also used commercially for the production of animal feed and starch-based products.

    In Africa, cassava provides a basic daily source of dietary energy. Once harvested the cassava roots spoil quickly and must be processed within 3 to 7 days to preserve their food value. The processing – cooking, grinding, drying or fermenting (varying according to local customs) is also necessary to neutralize the varying amounts of cyanide produced by the plant. The roots can be eaten in various forms: row, roasted, boiled, baked, fried, granules, pastes and flour. In most of the cassava-growing countries in Africa, the leaves are also consumed as a green vegetable, which provides protein and vitamins A and B.

    In Southeast Asia and Latin America, cassava has taken on an economic role. Cassava starch is used as a binding agent, in the production of paper and textiles, and as monosodium glutamate, an important flavouring agent in Asian cooking. In Africa, cassava is beginning to be used in partial substitution for wheat flour.


    How is it propagated?

    Cassava is propagated vegetatively by stem cuttings. Its production is therefore greatly dependent on the supply of quality stem cuttings. The multiplication rate of these vegetative planting materials is very low compared to grain crops, which are propagated by true seeds. In addition, cassava stem cuttings are bulky, difficult to transport and highly perishable as they dry up within a few days. Moreover, phytosanitary regulations prohibit the movement of cassava stem cuttings across international borders (to prevent the spread of diseases and insects), so special arrangements have to be done for storing and transportation of germplasm.



    Further reading

    Carter, S.E., Fresco, L.O., Jones, P.G., Fairbairn, J.N.1997. Introduction and diffusion of cassava in Africa, IITA Research Guide 49.

    Ceballos, H. 2006. Cassava research at CIAT [poster]. Centro Internacional de Agricultura Tropical (CIAT), Cali, CO. 1 p.

  • Chickpea ( 0 )
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    Please click on the boxes in the diagram below or use the menu on the left to go to the topic of your interest.

    • main ( 1 )
    • Collecting ( 31 )
    • Acquisition/Registration ( 2 )
    • Sample processing ( 1 )
    • Quality testing ( 5 )


      What is quality testing?

      The quality testing of seeds or plant materials assures that the materials to be conserved are in good conditions, i.e. can be grown again (viable) and are free of external contaminants (pests and diseases) and external genes (artificially produced genes). They are composed by three major aspects:

      - Viability testing
      - Plant health
      - Transgenes


      The quality of seed can be tested with a germination test











    • Methods of conservation ( 2 )
    • Cold storage ( 1 )
    • Tissue culture ( 1 )
    • Cryopreservation ( 1 )
    • Molecular ( 1 )
    • In field conservation ( 1 )
    • Characterization ( 1 )
    • Regeneration ( 1 )

      What is Regeneration?

      Regeneration is the renewal of germplasm accessions by sowing seeds or planting vegetative materials and harvesting the seeds or plant materials which will posses the same characteristics as the original population.

      Germplasm regeneration is the most critical operation in genebank management, because it involves risks to the genetic integrity of germplasm accessions due to selection pressures, out-crossing, mechanical mixtures and other factors. The risk of genetic integrity loss is usually high when regenerating genetically heterogeneous germplasm accessions. Germplasm regeneration is also very expensive.

      Regeneration on fields


      Why should germplasm be regenerated?

      Germplasm is regenerated for the following purposes:

      1. To increase the initial seeds or plant materials

      In new collections or materials received as donations, the quantity of seeds or plant materials received by the genebank is often insufficient for direct conservation. Seeds or plant materials may also be of poor quality due to low viability or infection. All these materials require regeneration. Newly acquired germplasm of foreign origin may need to be initially regenerated under containment or in an isolation area under the supervision of the national phytosanitary authorities.

      2. To replenishing seed stocks or plant materials in active and base collections

      Increase seed stocks or plant materials of accessions that have:

      - Low viability identified during periodic monitoring;
      - Insufficient stocks for distribution or conservation.

      Active collections should be regenerated from original seeds or plant materials in a base collection; this is particularly important for out-breeding species. Using seeds from an active collection for up to three regeneration cycles before returning to the original seeds or plant materials (base collection) is also acceptable (FAO/IPGRI 1994).

      Base collections should normally be regenerated using the residual seed or plant materials from the same sample.


      How is it done?

      If possible, regenerate germplasm in the ecological region of its origin. Alternatively, seek an environment that does not select some genotypes in preference to others in a population.

      If no suitable site is found, seek collaboration with an institute that can provide a suitable site or regenerate in a controlled environment such as a growth room.

      Examine the biotic environment in the context of prior information about the plants and past experience - an inappropriate biotic environment can be detrimental to plants, seed or propagation materials quality and the genetic integrity of an accession.

      Meeting special requirements
      There may be special requirements for regeneration of accessions with special traits that breeders and researchers use frequently—such as high-yielding, pest-and disease-resistant accessions and genetic stocks — or if there are insufficient seeds for safety duplication and repatriation.
      The following factors when regenerating germplasm accessions must be consider:

      - Suitability of environment to minimize natural selection;
      - Special requirements, if any, to break dormancy and stimulate germination (such as scarification);
      - Correct spacing for optimum seed set; and
      - Breeding system of the plant and need for controlled pollination or isolation.

      Regeneration in a protected environment

      When should it be done?

      It should be done when either the quantity and/or the quality of a particular seed or plant material are not sufficient in a genebank.

      The regeneration of accessions that have inadequate quality (low viability) should take priority over that of accessions with inadequate numbers of seeds or planting materials.

      The regeneration of accessions in base collections should take priority over regenerating those in active collections.


    • Dissemination ( 1 )
    • Safety duplication ( 1 )
    • Information/Documentation ( 1 )
    • List of equipment and supplies ( 1 )
  • Learning resources ( 0 )
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  • News ( 4 )

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