Lava Kumar, email@example.com
International exchange of germplasm: an essential step for sharing international public goods
Since its inception in 1967, IITA has been actively involved in the collection, conservation, and use of the plant genetic resources of important crops, such as banana and plantain, cassava, cowpea, maize, soybean, and yam, and their wild relatives from Africa and other parts of the world. Using this germplasm, IITAâ€™s crop improvement programs, based in several locations in sub-Saharan Africa, have been developing high-yielding, nutritionally superior crop varieties resistant to pests, diseases, and drought.
These are regularly exchanged with national and international programs for crop improvement and agriculture development.
Germplasm safety matters
As part of the measures to prevent the inadvertent spread of pests through exchange activities, IITA has established a Germplasm Health Unit (GHU). The GHU is responsible for the production, maintenance, and exchange of healthy (pest-free) germplasm in accordance with the international requirements on plant protection. These are covered by the International Plant Protection Convention (IPPC) under the auspices of FAO, and those set up by the Inter-African Phytosanitary Council (IAPSC) and National Plant Protection Organizations (NPPOs) to safeguard agriculture and natural resources from the risks associated with the entry, establishment, or spread of plant pests.
GHU (a) facilitates germplasm exchange in support of IITAâ€™s international crop improvement programs; (b) inspects for pests and certifies the health status of germplasm; (c) ensures compliance with the national regulations on plant introductions and exports; (d) guards against the introduction of exotic pests into countries where they do not occur; (e) ensures phytosanitary management of plant genetic resources conserved in the IITA genebank; and (f) provides capacity building and awareness creation on phytosanitary measures.
GHU operates within the framework of the procedures for the introduction and export of germplasm established by the government of the host country in which IITAâ€™s operations are based. For instance, all the exchange operations of IITAâ€™s activities in Nigeria are organized in accordance with the legislation of the Nigerian Agriculture Quarantine Service (NAQS) of the Federal Department of Agriculture, Nigeria.
Ensuring exchange of clean germplasm
Crops researched at IITA comprise those propagated through botanical seeds or true seeds (maize, soybean, cowpea, and other legumes of importance to African farming) and crops that are propagated through vegetative propagules, including stems (e.g., cassava), tubers (e.g., yam), and in vitro plants (e.g., banana and plantain, cassava, and yam).
Each type of germplasm demands a unique set of procedures for assessing the health status of the material. At IITA, this work goes on from production to postharvest to the point when the material is dispatched.
Plant material generated for international exchange is inspected with the technical officers of NPPO during the active growth stage in the field or screenhouse to ensure the selection of pest-free material. The sorted materials (seeds or vegetative propagules) are then brought to the GHU laboratories for critical inspection for the presence of pests. Detection methods used for this purpose include visual inspection of dry seeds, seed washing, agar and blotter tests, seed soaking, and seedling symptom tests which aid in identifying any pest-infested material. Additional techniques are used for pest identification including culturing techniques, microscopy, and biochemical analyses of samples by enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), and genomic sequencing. Only materials that are free of the regulated and unregulated quarantine pests are released for international exchange.
GHU also monitors for genetically modified organisms (GMO) to comply with the Cartagena biosafety protocol, also under the regulation of NPPOs. This is done mainly by seeking an additional declaration from the exporting parties on the GMO status of the planting material as stipulated in the conditions of the import permit issued by the NPPO. Diagnostic capacity exists to monitor germplasm for traces of GMOs by PCR assays, targeting constitutive elements of transgene constructs, such as promoters of Agrobacterium tumefaciens or Cauliflower mosaic virus 35S gene, that are widely used for generating transgenic plants.
Complying with regulations
Germplasm exchange activity commences with the application of a permit from a host country for germplasm import (for use in IITAâ€™s R4D programs) or germplasm export (to partners, collaborators and other stakeholders, including IITAâ€™s missions in other countries). This is an essential process under the Convention of Biological Diversity (CBD) treaty that regards biodiversity as a national treasure, and requires authorization from the respective governments for free exchanges. Every country has a nodal agency tasked with issuing permits for the movement of germplasm.
In addition, GHU applies for phytosanitary certificates (PC) for the export of material. The PC is issued by NPPO after the condition has been satisfied that the material being exported meets the phytosanitary standards of the IPPC and the importing country. GHU invariably complies with national regulations in obtaining these two documents for all seeds or plant materials sent or received. Similarly, when material is imported it is subjected to post-entry inspection to ensure its compliance with the conditions specified in the import permit. Depending on the need, material is held in the post-entry isolation facility until the necessary clearances are obtained. Material that satisfies all the conditions is released for IITAâ€™s use.
From 2005 to 2010, GHU, from IITAâ€˜s Ibadan Station in Nigeria in liaison with NAQS, has facilitated about 492 exchanges, 157 imports, and 335 exports of crop and other plant material to 69 countries, 34 of which are in Africa (Fig. 1). USA, India, Colombia, Mexico, and Japan are among the top 5 non-African countries. Within Africa, the top 5 countries with which IITA has exchanged germplasm are BÃ©nin, Ghana, Cameroon, Kenya, and South Africa. Each of these countries has specific legislation. However, procedures for health monitoring have the same underlying principle, i.e., the exclusion of pests and the prevention of pests from spreading.
Phytosanitary protection of genetic resources
GHU ensures the phytosanitary management of the germplasm of food crops (about 27,000 accessions) conserved in the IITA genebank and also in the in situ germplasm collections of breeding programs. Germplasm conserved in the genebank is systematically evaluated for its health status and clean germplasm is conserved for distribution by IITAâ€™s Genetic Resources Center (GRC).
Contributing to phytosanitary capacity development in SSA
Together with the Virology and Molecular Diagnostic Unit and GRC at IITA, Ibadan, GHU augments diagnostic procedures for monitoring pests in germplasm; develops a reference pest collection and DNA bank to use as controls; establishes DNA barcode databases of the pests of African food crops; and augments procedures for salvaging clean germplasm.
GHU plays an active role in developing the skills of NPPOs in the testing for germplasm health and the production of pest-free germplasm via training courses and short-term assignments. It also creates awareness on quarantine pests, quality standards for planting material, and the sanitary and phytosanitary (SPS) measures.
Knowledge and technologies developed are disseminated through training programs, the publication of protocol manuals, information flyers and a website. The unit also collaborates with NPPOs and IAPSC as a technical partner to develop phytosanitary capacity in Africa.