IITA IPM project 13: Development of Dioscorea rotundata and D. alata varieties with high and stable yield of good quality tubers that contribute to a sustainable increase in productivity of yam-based systems

Duration: 3years (2003 – 2005)

Purpose: To increase adoption by farmers of new, improved D. rotundata and D. alata varieties with high and stable yield of good quality tubers contributing to sustainable increase in productivity of yam-based systems.

Background/description: This project builds on earlier Gatsby Charitable Foundation-funded projects on yam genome mapping and breeding for resistance to viruses infecting yams. This study will address the following: D. rotundata germplasm with high levels of virus resistance (particularly to Yam mosaic virus (YMV), genus Potyvirus) will be produced and tested in collaboration with NARS and potential end-users. New varieties of D. rotundata that are superior in field performance to existing cultivars will be identified through collaborative testing with NARS and farmers' groups. Improved D. alata germplasm with anthracnose resistance and desirable tuber food quality will be developed, produced and tested in collaboration with NARS and potential end-users. New varieties of D. alata that are superior in field performance to existing cultivars will be identified through collaborative testing with NARS and farmers' groups. A range of diagnostic tools will be developed for the characterised viruses infecting yams (and any previously uncharacterised viruses that may be isolated). Appropriate diagnostic tools for viruses occurring in yams will be distributed, and training provided, to collaborating NARS and national plant quarantine services to ensure both safe international movement of yam germplasm and to assist in the development of systems to disseminate healthy planting material to farmers

Agroecozone(s) and location(s): Hunid Forest and wet savannas of West Africa

Expected outputs: a) D. rotundata populations with high levels of resistance to YMV developed and disseminated to NARS; b) New varieties of D. rotundata, superior in field performance to existing cultivars, identified through collaborative testing with NARS and farmers' groups; c) D. alata populations with high levels of resistance to anthracnose and improved tuber food quality developed and disseminated to NARS; d) New varieties of D. alata, superior in field performance to existing cultivars, identified through collaborative testing with NARS and farmers' groups; e) A range of diagnostic tools available for the characterised viruses (and any previously uncharacterised viruses that may be isolated) infecting yams; f) Appropriate diagnostic tools for viruses occurring in yams disseminated to collaborating NARS and national plant quarantine services

Potential impact and beneficiaries: This project will enable farmers to adopt new, improved D. rotundata and D. alata varieties with high and stable yields and good quality tubers. This project will support local initiatives to develop schemes to produce ?clean' seed yams by enabling the growers to perform some virus testing/certification themselves. It will also assist the safe international movement of germplasm, thus facilitating international trade

Partners: a) National Agricultural Research Organizations;

Development investor(s): Gatsby Foundation

IITA contact person(s)/principal investigator(s):, Jacqueline Hughes J.Hughes@cgiar.org and Robert Asiedu R.Asiedu@cgiar.org website http://www.iita.org