Rice yellow mottle virus genus Sobemovirus: a continental problem in africa

Abstract

<I>Rice yellow mottle virus</I> genus <I>sobemovirus </I>(RYMV) was first reported in Kenya in 1966. The disease caused by this virus is fast becoming a major limiting factor in the rice production in Africa and neighbouring islands. It is known to occur in eastern, western and southern African countries and, since very recently, in Central Africa. It is transmitted by insect vectors such as <I>Chaectonema </I>spp., <I>Sesselia pusilla</I> Gerst. and <I>Trichispa sericea</I> Guerin (all <I>Coleoptera</I>) and also by mechanical means. About six strains of the virus now exist. Yield losses caused by the virus range from 20 to 100%. Integrated pest management has been suggested to minimise damage caused by this disease to rice. This paper reviews the characteristics of the virus, symptomatology, host range, distribution, strains, transmission, vector dynamics and virus spread, the economic importance, and management strategies. The need of future research of RYMV is also highlighted.