Etiology of African Cassava Mosaic Disease. K. R. Bock, Leader, Overseas Development Administration/Kenya Agricultural Research Institute Crop Virology Research Project, Nairobi, Kenya. R. D. Woods, Electron Microscopist, Plant Pathology Department, Rothamsted Experimental Station, Harpenden, Hertfordshire AL5 2JQ, England. Plant Dis. 67:994-995. Accepted for publication 20 February 1983. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-994.

Isolates of both the type and coast strains of cassava latent virus (CLV) were inoculated mechanically to the mosaic-sensitive cassava cultivar N Mex 55, in which they induced symptoms typical of African cassava mosaic disease. CLV was recovered from these infected plants by standard sap-transmission inoculations to Nicotiana benthamiana and gemini particles were subsequently detected in leaf-dip preparations of them, indicating this virus is in fact the causal agent of mosaic disease. Transmission rates were low (4/20 and 10/50 for CLV-C and CLV-T, respectively) when partially purified virus preparations from infected N. benthamiana were used as inocula but were comparatively high (11/26) when partially purified preparations of CLV-C from mosaic-affected cassava were used. It is apparent that the name cassava latent virus is no longer valid and that the pathogen should be referred to as cassava mosaic virus.