Viruses Infecting Yam in Africa: Existing Knowledge and Future Perspectives

Yam is one of the nutritional crops feeding a large population in West Africa in particular and currently expanding to the other parts of the continent. However, its productivity is being hampered by biotic stresses particularly viruses which are mainly propagated through infected tubers as planting materials. Viruses infecting yam have been reported worldwide in yam production areas affecting both the quality and quantity of tubers, subsequently interfering with the international germplasm exchange. There are few, not well-described yam viruses in Sub-Saharan Africa (SSA) that induce such symptoms as mosaic, chlorotic spotting, curling and mottling. Despite the strides made in describing and diagnosing yam viruses in SSA, a lot remained and is still unknown due to scarcity and limited access to knowledge, particularly the epidemiology of yam viruses. This review presented the current status of yam viruses occurring in Africa. Future directions on yam viruses and diagnostics using molecular methods are discussed.