Genetically distinct strains of Cassava brown streak virus in the Lake Victoria basin and the Indian Ocean coastal area of East Africa
Six isolates of Cassava brown streak virus (CBSV, genus Ipomovirus; Potyviridae) from the Lake Victoria basin in Uganda and Tanzania were characterized. Virus particles were 650 nm long. The complete coat protein (CP)-encoding sequences (1,101 nucleotides, nt) were 90.7–99.5 and 93.7–99.5% identical at the nt and amino acid (aa) levels, respectively. The 3′ untranslated region was 225, 226 or 227 nt long. These eight isolates were only 75.8–77.5% (nt) and 87.0–89.9% (aa) identical when compared to the partial CP sequences (714 nt) of six CBSV isolates characterized previously from the costal lowlands of Tanzania and Mozambique. Hence, two genetically different and geographically separated populations of CSBV exist in East Africa.
KeywordsCoat Protein Reverse Transcription Polymerase Chain Reaction Cetyl Trimethyl Ammonium Bromide Cassava Plant Coastal Lowland
We thank Anu Kallinen, Johanna Aura, Marja Calonius, Sascha Kirchner and Peter Wasswa for technical assistance. This study was part of the project “Towards Sustainable Cassava and Sweet Potato Production in Eastern Africa” under the East African Regional Network for Biotechnology, Biosafety and Biotechnology Policy Development programme (BIO-EARN). Funding from Sida, Sweden, and the assistance of the Stockholm Environment Institute (SEI) are gratefully acknowledged.
- 4.Bock KR (1994) Studies on cassava brown streak virus disease in Kenya. Tropical Sci 34:134–145Google Scholar
- 7.FAOSTAT (2007) FAO database. Food and Agriculture Organization of the United Nations, Rome, Italy. http://faostat.fao.org/site/567/default.aspx
- 8.Fauquet CM, Mayo MA, Maniloff J, Desselberger U, Ball LA (2005) Virus taxonomy: the eighth report of the International Committee on Taxonomy of Viruses. Elsevier, San DiegoGoogle Scholar
- 11.Harrison BD, Swanson MM, Robinson DJ (1995) Cassava viruses in the Old World. In: Proceedings of the Second International Scientific Meeting, Bogor, Indonesia, CIAT Working Document, Cassava Biotechnology Network 150, pp 298–301Google Scholar
- 18.Lennon AM, Aiton MM, Harrison BD (1986) Cassava viruses from Africa: third country quarantine. In: Report for 1985. Scottish Crop Research Institute, Invergowrie, UK, pp 168–169Google Scholar
- 27.Muga T, Thresh JM (2002) Incidence of cassava mosaic and cassava brown streak virus diseases in coastal Kenya. Roots 8:12–14Google Scholar
- 30.Nichols RFW (1950) The brown streak disease of cassava: distribution climatic effects and diagnostic symptoms. East Afr Agric J 15:154–160Google Scholar
- 31.Shukla DD, Ward CW, Brunt AA (1994) The potyviridae. CAB International, WallingfordGoogle Scholar
- 32.Storey HH (1936) Virus diseases of East African plants: VI-A progress report on studies of the disease of cassava. East Afr Agric J 2:34–39Google Scholar