The publication consists of 33 chapters written by about 40 scientists and conservationists that cover an evaluation of 550 species based on the IUCN (International Union for Conservation of Nature, http://www.iucn.org/) criteria.
The book is of interest to those working in nature conservation, including schools, NGOs, government agencies, policymakers, as well as tourists.
The book was produced with the generous support of the following partners: Swiss Agency for Development and Cooperation (SDC), Leventis Foundation, Netherlands Embassy (Benin), and Helvetas (Switzerland).
Copies are available for sale from IITA. To get a copy, please contact Peter Neuenschwander, IITA-Benin, at email@example.com or Katherine Lopez, IITA, Ibadan, Nigeria, at firstname.lastname@example.org.
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.
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.
Dominique Dumet, email@example.com and Lava Kumar, firstname.lastname@example.org
Plant genetic resources (germplasm) are the foundation for sustainable agriculture and global food security. They possess genes that offer resistance to pests and diseases and resilience to abiotic stresses, such as drought tolerance, soil erosion, and other constraints.
However, genetic resources are eroding at unprecedented rates as a result of the loss of habitat, outbreaks of pests and diseases, and abiotic stresses. Therefore, it has become imperative to conserve genetic resources for agricultural sustainability and the preservation of global biodiversity.
In the mid-1970s, IITA has initiated an ex situ conservation of germplasm of important African food crops which are held in trust on behalf of humanity under the auspices of the United Nations. To date, IITAâ€™s Genetic Resources Center (GRC) conserves over 27,000 accessions of six main collections of African staple crops, namely, cowpea and other Vigna, soybean, maize, cassava, banana, and yam. Germplasm is distributed worldwide for use in research for food and agriculture. Depending on the speciesâ€™ reproductive biology and mode of dissemination, collections are stored in field, seed, or in vitro genebanks.
However, germplasm (seeds or vegetative propagules) infested with pathogens such as, viruses, fungi, bacteria, and nematodes, insects, mites and even weeds (hereafter all referred to as pests) can spread along with the planting materials. Because of this risk, planting materials are traditionally sourced from healthy-looking plants and as an additional safety measure they are treated with chemicals to eliminate bacteria, fungi, nematodes, insects and other pests. However, viral pathogens are difficult to detect and pose challenges to â€œcleanâ€ (pest-free) planting material production procedures. IITA’s collections were sourced over 35 years from several countries in Africa and other parts of the world.
Knowledge on viruses infecting crops conserved in the IITA genebank and the means for their detection and production of clean planting material have dramatically improved over the past two decades. To ensure that germplasm conserved is free of pests, particularly viruses, a systematic approach was taken to assess the health status of every accession in the genebank and produce clean planting materials for conservation.
For seed-propagated crops (maize and legumes), clean seed production requires planting accessions in contained screenhouses. Emerging plants are monitored for symptoms and each plant is tested using diagnostic tools for all known seed-transmitted viruses occurring in the territory where they were last grown. Plants that test positive for virus and/or showing virus-like symptoms are destroyed. Seeds are harvested from the virus-negative, healthy-looking plants. Clean seeds are then deposited in the germplasm collections. This work started in 2008, and so far over 4000 accessions of legumes have been evaluated and clean seed material produced have been conserved in the genebank.
For clonally propagated crops (cassava, yam and banana), production of clean planting material involves in vitro procedures using meristem culture. In cassava, source plants are subjected to thermotherapy (exposing plants to 27-30 Â°C) from 1 to 3 weeks prior to meristem excision and in vitro propagation. In vitro plants are indexed for viruses and plants that test positive are discarded while virus-negative plants are further propagated for conservation in the in vitro genebank. So far, over 2000 accessions of clonal crops have been subjected to this process to derive virus-free plants.
Production and conservation of “clean” planting material is expensive; however it improves the turn-around time for processing germplasm for exchange and dramatically improves its use. In addition, clean germplasm improves the viability of the material conserved in the genebank and prevents the risk of the accidental spread of pests from one region to another through the planting materials.
Crop improvement through breeding and biotechnology is one way of tackling the challenges of feeding the world. Conservation of genetic resources is an important component of crop improvement, providing a pool of materials for the researchers to draw from.
IITAâ€™s Genetic Resources Center (GRC) created in 1975, maintains over 28,000 accessions of six main staple crop collections that are available to food and agriculture researchers worldwide working on crop improvement. They are cowpea or â€œblack-eyed peaâ€ (Vigna unguiculata L.), maize (Zea mays L.), soybean (Glycine max (L.) Merr.), cassava (Manihot esculenta Crantz), yam (Dioscorea spp.), and banana (Musa spp.).
Over 50% of the collection is made of cowpea collected from 89 countries, mainly in Africa, and other Vigna spp. It is also the most shared, with 54 of all the germplasm materials being distributed.
Since 1985, IITA has distributed germplasm of cowpea and its wild Vigna relatives for genetic improvement research to institutions in sub-Saharan Africa, Asia, USA, and South America. This has contributed to the development of new cultivars or varieties currently adopted by rural farmers in the regions.
The effectiveness of the distribution system from the genebank, the use of the distributed germplasm, and conservation costs were assessed in a study conducted by Victor Manyong, Dominique Dumet, and A.T. Ogundapo from IITA and D. Horna from the International Food Policy Research Institute. Likewise, the impact of the conservation of germplasm of cowpea and wild relatives was examined to justify the conservation efforts.
Questionnaires were e-mailed to partners who had collected germplasm from GRC between 1975 and 2009 to determine the ease of accessing material and their use. To estimate the cost of conserving a unit of the two crops, the Decision Support Tool (DST) developed by IFPRI was used.
Only about 13% of the beneficiaries responded but they accounted for about 84% of the accessions distributed to beneficiaries in West Africa, Asia, East Africa, Europe, and North America.
No responses were received from beneficiaries in Australia, the Caribbean, Central Africa, the Middle East, North Africa, South Africa, and South America. This may partly have been due to lack of updated contact details in the genebankâ€™s electronic database. This needs to be improved for future feedback surveys.
Use of cowpea and wild Vigna germplasm
The study findings show that most of the distributed cowpea and wild Vigna accessions were used for breeding followed by activities in agronomy and biotechnology research. However, in many cases, they had multiple uses, such as breeding, biotechnology, and agronomy.
Between 2001 and 2005, about 76% of the accessions were used for various agricultural research activities and were found adaptable to different agroecological zones, from forest to the savanna in the tropics and subtropics. Derived, Sudan, and Sahel savannas were recognized as the adaptable agroecological zones for the cultivation of cowpea and wild Vigna.
The majority of the users of the germplasm found it easy (32%) to very easy (68%) to get the material from the genebank. Only a few experienced difficulties. These included the inability of the genebank to supply the required quantities (3% of accessions), poor collaboration with NARS and universities (3%), long bureaucratic procedures to acquire germplasm (2%), and improper documentation of the passport database of accessions (1%).
High yield and pest resistance were the two traits desired by the majority of agricultural researchers who made requests, irrespective of their specialization. Other desired traits included compatibility to cross with other accessions, seed color and size, nutritive value, palatability and attractiveness, drought tolerance, nematode resistance, early flowering, and storability.
Moreover, many were satisfied with the accessions they received. Findings show that 68% of the accessions received by agronomists met their desired traits, 76% for food technologists, but only 3% for breeders where the main issue was the low level of resistance to pests and diseases. However, the breeders recorded 100% satisfaction in the exploitation of accessions for seed color, seed size (good), and compatibility with crossing. Likewise, 95% satisfaction was achieved on high seed yield and 74% on the combination of high yield and pest resistance by some of the breeders.
Cost of conservation
The structure cost of the genebank in the DST has four categories: capital, quasi-fixed, variable labor input, and variable nonlabor input. Capital inputs include infrastructure, such as germplasm storage and genebank facilities, and equipment for field operations and offices.
Using 2008 as a reference year, US$358,143 and $28,217 was spent annually on the conservation and management of cowpea and wild Vigna. The capital cost took the major share of the costs, followed by quasi-fixed costs for scientific staff, nontechnical labor, and nonlabor supplies and consumables. Each accession cost about $72 for cowpea and only about half of that for wild Vigna. A large share of the expenditure, $28,537, went into the regeneration of 2,228 accessions of cowpea, at an average cost of approximately $12.81 per accession.
Cowpea germplasm is regenerated in the screenhouse to produce high quality germplasm, with considerations of purity and sanitation, hence the relatively high cost per accession. Seed health testing ($13.94/accession) and distribution ($22.63/accession) were the other high costs.
One way to reduce these costs is by increasing the number of accessions, thus lowering the unit cost. Also, upgrading and expanding the current infrastructure to improve the efficiency of the genebank were recommended.