Genetic diversity and phylogeography of cassava mosaic viruses in Kenya
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Date
2006Author
Bull, Simon, E.
Briddon, Rob, W.
Sserubombwe, William, S.
Ngugi, Kahiu
Markham, Peter, G.
Stanley, John
Type
ArticleLanguage
enMetadata
Show full item recordAbstract
Cassava is a major factor in food security across sub-Saharan Africa. However, the crop is
susceptible to losses due to biotic stresses, in particular to viruses of the genus Begomovirus
(family Geminiviridae) that cause cassava mosaic disease (CMD). During the 1990s, an epidemic
of CMD severely hindered cassava production across eastern and central Africa. A significant
influence on the appearance of virus epidemics is virus diversity. Here, a survey of the genetic
diversity of CMD-associated begomoviruses across the major cassava-growing areas of Kenya is
described. Because an initial PCR-restriction fragment-length polymorphism analysis identified a
much greater diversity of viruses than assumed previously, representative members of the
population were characterized by sequence analysis. The full-length sequences of 109
components (68 DNA-A and 41 DNA-B) were determined, representing isolates of East African
cassava mosaic virus and East African cassava mosaic Zanzibar virus, as well as a novel
begomovirus species for which the name East African cassava mosaic Kenya virus is proposed. The
DNA-B components were much less diverse than their corresponding DNA-A components, but
nonetheless segregated into western and eastern (coastal) groups. All virus species and strains
encountered showed distinct geographical distributions, highlighting the importance of preventing
both the movement of viruses between these regions and the importation of the disease from
adjacent countries and islands in the Indian Ocean that would undoubtedly encourage further
diversification.
URI
http://www.ncbi.nlm.nih.gov/pubmed/16963765http://erepository.uonbi.ac.ke:8080/xmlui/handle/123456789/14922
Citation
Journal of General Virology (2006), 87,Publisher
Department of plant Science and crop protection, University of Nairobi
Description
Journal article