Cassava is a food security crop to more than 600 million people in the developing world, providing incomes to resource-poor farmers, improving their livelihoods, and serving as a buffer against food crises.
The strategic importance of cassava, however, is being threatened, especially in Africa, as local varieties are in danger of disappearing because of genetic erosion and other human and natural factors.
â€œIn Guinea, for instance, about seven local cassava varieties are fast disappearing. This is risky, especially for cassava since it is a clonal crop,â€ according to Paul Ilona, IITA Senior International Trials Manager. Clonal crops are those propagated through cuttings or other plant parts, not by seeds.
Genetic erosion is a process whereby the already limited gene pool of an endangered species of plant or animal diminishes even more when individuals from the surviving population die out without getting a chance to breed within their endangered low population.
Both local and improved cassava varieties alike create a robust gene pool, offering choices for breeders in future breeding programs. However, the loss of genes from the extinction of some local varieties could limit future improvement programs. The endangered varieties may hold key traits that could offer possible solutions to hunger and poverty in the future.
To prevent the genetic erosion of cassava, IITA and the Institut de Recherche Agronomique de GuinÃ©e (IRAG) have stepped up efforts to save native African varieties with the collection of 73 local varieties from Guinea, West Africa.
These varieties are now conserved under ex situ conditions at IITAâ€™s Genetic Resources Center (GRC) in Ibadan, Nigeria. They form part of a collection to safeguard the continentâ€™s plant genetic resources. The collecting mission in that West African country last year was funded by the Global Crop Diversity Trust (GCDT), IRAG-Guinea, and IITA.
â€œThe conservation of local varieties provides hope for future cassava breeding programs and helps to guarantee food security in Africa,â€ says Dominique Dumet, GRC Head and coordinator of the collecting mission.
Ilona says the loss of native cassava varieties might limit the number of genes available for breeders to work with. â€œFor breeders, any time we lose (crop) genes, it hurts. That is why the conservation of local cassava varieties at GRC is important to us,â€ he says.
Apart from cassava, the IITA-GRC holds over 25,000 accessions of major African food crops, including cowpea, yam, soybean, bambara nut, maize, and plantain/banana. IITA shares these accessions without restriction for use in research for food and agriculture.
The collecting mission makes Guinea the fourth country, after Angola, Togo, and BÃ©nin, to allow IITA to collect and share their germplasm with other countries, since the International Treaty on Plant Genetic Resources for Food and Agriculture went into force in June 2004.