Development of a long term strategy based on genetic resistance and agroecological approaches against Coffee Wilt Disease in Africa : Fourth annual report: Covering period 1/11/2004 to 31/10/2005
Coffee wilt disease is the major constraint to robusta culture in the different partner countries. The disease spread quickly in Tanzania. In Ethiopia, arabica culture area, the disease remained at a very low threshold for many years, but the damage increased significantly since the end of 1990s. Consideration of the status of C. arabica is essential, because to develop resistance it is necessary to accumulate résistance genes for the two forms of the pathogen. Currently, every form of Fusarium xylarioides is species specific. But there are some indicators leading to the thinking that the evolutionary potential of the fungus can drive to emergence of new virulence with no specific species reaction. Variety resistance is considered the best option for an effective control of the coffee wilt disease and therefore the main objective of this project remains, to develop a global strategy to fighting the disease, based on durable tolerance/resistance, that is adapted to small holder agro-system and to the economic conditions prevailing in Africa. In year 4, the work carried out built on results obtained in year 3. i.e: 1- Study the genetic diversity of the pathogen with different technics. 2- Assess the aggressiveness of isolates and characterize interactions. 3- Identify coffee trees bearing resistance factors. 4- Analyse genetic diversity of Coffea canephora from Uganda. 5- Analyse disease distribution in the field. 6- Assess correlations between field resistance and artificial inoculation tests.