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Conservation and utilization of Yam (Dioscorea sp) Biodiversity in Benin . Prof. Alexandre A. DANSI Laboratory of Agricultural Biodiversity and Tropical Plant Breeding; Faculty of Science and Technology, University of Abomey-Calavi ( Republic of Benin ). Introduction
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Conservation and utilization of Yam (Dioscorea sp) Biodiversity in Benin Prof. Alexandre A. DANSI Laboratory of Agricultural Biodiversity and Tropical Plant Breeding; Faculty of Science and Technology, University of Abomey-Calavi (Republic of Benin)
Introduction • Status and spatial distribution of yam diversity in Benin • Role of the related wild species in the evolutionary dynamic of the cultivated forms • Conservation strategies • Participatory evaluation and utilization • Recommendations for yam biodiversity conservation
Introduction • Benin is one of the most important yam producing countries of the African yam belt • Annual production estimated à 2.5milliontonnes (FAO 2009) • Ranked 4th behind Nigeria, Cote d’Ivoire and Ghana (total annual production) • Most important food crop in Benin (FAO 2009)
Species produced are: Dioscorea cayenensis / D. rotundata (about 400 clones) Dioscorea alata Dioscorea bulbifera Dioscorea esculenta Dioscorea dumetorum Wild species Dioscorea praehensilis - South Dioscorea abyssinica – North Dioscorea burkilliana - Ahozon 5 %
Different studiesMorphological characterization for D. rotundata and D. cayenenis : morphotypes (140 ) and cultivar groups (30) • For all species: • isozymiccharacteristion • RAPD characterisation • SSR and AFLP • Yam domestication and the evolutionary dynamic of yam • In situ conservation (reserve design / on farm conservation) • Diversity assessment at community level: state of yam diversity /conservation and utilization strategy
Different studies (continued) • Participatory morphological characterization characterization for D. rotundata, D. cayenennis and D. alata • Participatory evaluation • Abiotic stresses • Tolerance to high soil moisture • Resistance to drought / Stay-green ability • Adaptability to poor soil • Biotic Stresses • Resistance to pests and diseases
Different studies (continued) • (yam nematodes , insects, etc) • Susceptibility to weeds • Agronomic parameters • Relative productivity • Number of tubers per mound • Storage aptitude to fresh tuber • Quality of the cossettes • Storage aptitude of the cossettes • Quality of the pounded yam • Quality of the boiled yam
Status and spatial distribution of yam diversity in Benin Zone I Diversity Minimum 14 Maximum 80 Average 37 Earlymaturing 19 Latematuring 18 Genetic Erosion Minimum 12,82 Maximum 68,42 Average 39,67 Zone 2 Diversity Minimum 13 Maximum 48 Average 24 Earlymaturing 8 Latematuring 16 Genetic Erosion Minimum 4,55 Maximum 65,85 Average 39,78
Status and spatial distribution of yam diversity in Benin Zone 4 Diversity Minimum 05 Maximum 11 Average 6 Earlymaturing 5 Latematuring 1 Genetic Erosion Minimum 33,33 Maximum 75 Average 58,73 Zone 3 Diversity Minimum 6 Maximum 51 Average 20 Earlymaturing 14 Latematuring 6 Genetic Erosion Minimum 11,11 Maximum 51,61 Average 32,95
Farmers’ preference criteria: variable across diversity zones, ethnic zones and gender
Thank to the TRUST, complementary approaches are being used to conserve and at the same time use yam diversity in Benin • National field genebank of 1017 accessions established in collaboration with local communities at Dendougou (Djougou) • Duplication of all the accessions to IITA Genebank for in Vitro conservation and other purposes • Zonal genebank established in each of the diversity zone to ease and increase farmer access to existing diversity
Other ongoing or planned actions include: • Construction of a comprehensive Excel database • morphology • agronomic characteristic • Production zone; distribution and extent • Setting up of a farmers and NGO network for on-farm conservation and sustainable utilisation of yam biodiversity • Public awareness action: workshops, community radio programmes , fact sheets in local languages, etc. • Training workshops on diverse aspects of genetic resources conservation and management at community level for agricultural technicians and for the leaders of farmers’ associations.
Intensification of the variety exchanges between villages and production zones • Local yam diversity fairs • Diversity book at community level • Participatory breeding will also be conducted using specific breeding block design