General principles underpinning safe transfer of tissue cultured clonal germplasm
Contributors to this section: CIP, Lima, Peru (Carols Chuquillanqui, Segundo Fuentes, Ivan Manrique, Giovanna Muller, Willmer Pérez, Reinhard Simon, David Tay); CIP, Nairobi, Kenya (Ian Barker); FERA, UK (Derek Tomlinson, Julian Smith, David Galsworthy, James Woodhall).
Over a ten year period beginning in the late 1980s, FAO/IBPGR commissioned a number of Technical Guidelines intended for the safe movement of small quantities of crop plant germplasm between countries for the use in breeding, research and germplasm conservation and evaluation programmes. Occasionally, in response to pest and disease epidemics, larger quantities of disease resistant/tolerant germplasm were transferred for incorporation into rapid multiplication schemes to replace crop plants lost to disease. An example of this has been the shipment of Cassava mosaic disease resistant cassava clones from the International Institute of Tropical Agriculture (IITA) for incorporation into the multiplication programmes of a number of African countries to replace cassava destroyed in the 1990’s Cassava mosaic disease pandemic.
Few of the guidelines have been revised since their publication and information has become dated, particularly in relation to diagnostics. Furthermore, it is accepted, given the now almost universal access to internet resources, that a new approach involving a web-based database will be more appropriate than the existing guides. Such a database can be more readily updated by designated crop plant and pest and disease specialists, resulting in a more robust document that will remain relevant. There is thus a need to update the guides.
These changes withstanding, the principles outlined by Jeffries’ (1998) in the technical guide for the safe movement of potato germplasm still apply and require only minor modifications before applying to the movement of other germplasm.
- These guidelines apply to tissue cultured clonally cultivated species (Solanum, Manihot, Musa, Ipomoea and Dioscorea) and are intended for use by research workers and specialised institutions engaged in plant breeding, germplasm conservation and evaluation.
- International movement of germplasm must comply with the regulatory requirements of the countries involved. Prospecting activities for conservation must be based on prior consultation with the relevant plant protection organisations (PPOs) and a knowledge of organisms in the relevant countries.
- Information exchange between exporter and importer must be sufficiently transparent for a full evaluation of the pest risk. Wherever possible, material should be selected from the least risk source, e.g. an institution which maintains pathogen-tested germplasm. Indexing procedures and precautions taken to prevent infection and contamination of the germplasm after testing should be documented, e.g. in a 'Germplasm Health Statement'.
- Growing of untested germplasm outside effective containment and/or isolation is not recommended. Collecting and conservation activities must be preceded by establishing the nearest point where the material can be placed in quarantine containment.
- Movement of pathogen-tested stem cuttings is not recommended because of the risk of the material becoming infected after testing.
- Pathogen-tested material should be derived from tested parents and maintained under conditions designed to prevent infection and contamination. Absence of pathogens should be established by applying appropriate indexing procedures and these should be verified as appropriate.
- Risks can be reduced further by post-entry quarantine containment (e.g. insect-proof houses, out-of-season cultivation, growing in an isolated area with no links to the material involved) and quarantine testing. Post-entry quarantine containment/testing is a requirement in many countries. Some countries, however, will accept the testing done by specified countries as being equivalent to their own and accept material without the need for post-entry quarantine containment/testing. Untested or infected material must be managed so as not to be a risk to tested material.
- The volume of consignments should not be larger than is necessary to preserve the genetic usefulness of the germplasm. In the case of vegetative material and seeds, quantities recommended are 1-10 plants and 20-200 seeds respectively. Increasing quantities may lead to resource problems in containment and testing.
- Some PPOs stipulate that each unit (in vitro plantlet, seed/seedling and pollen-derived plant) of germplasm is tested individually for quarantine pests, whereas other authorities allow, particularly for seed, test results derived from bulked samples representative of the consigned germplasm.
Normally in vitro material contaminated with saprophytic organisms should be destroyed. However, where the material is rare or valuable, such contamination may be dealt with by appropriate treatments. Antibiotics and fungicides must not be added to the medium for shipment.
These recommendations are adapted from Jeffries, 1998. A number of International Standards for Phytosanitary Measures (ISPM) apply to he transit of clonal germplasm in international trade. Information by Seabrook and Coleman (1988) on the shipping of in-vitro material is still pertinent.
- Technical recommendations for the exporting country
- Technical recommendations for the importing country
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Contributors to this section: CIP, Nairobi, Kenya (Ian Barker); CIP, Lima, Peru (Carols Chuquillanqui, Segundo Fuentes, Ivan Manrique, Giovanna Muller, Wilmer Pérez, Reinhard Simon, David Tay); FERA, UK (Derek Tomlinson, Julian Smith, David Galsworthy, James Woodhall).