Diversity of begomoviruses associated with mosaic disease of cultivated cassava (Manihot esculenta Crantz) and its wild relative (Manihot glaziovii Mull. Arg.) in Uganda.
Cassava (Manihot esculenta) growing in Uganda during 2001-2002 has been screened for the presence of begomoviruses using PCR-RFLP, cloning full-length genomic components and nucleotide sequence analysis. In contrast with a recent survey in neighbouring Kenya, which identified three distinct strains of East African cassava mosaic virus (EACMV, EACMV-UG and EACMV-KE2) as well as East African cassava mosaic Zanzibar virus and the new species East African cassava mosaic Kenya virus, only EACMV-UG and, to a lesser extent, African cassava mosaic virus (ACMV) were found associated with cassava in Uganda. The integrity of the cloned genomic components of representative virus isolates was confirmed by demonstrating their infectivity in Nicotiana benthamiana and cassava using biolistic inoculation, providing a convenient means to screen cassava varieties for disease resistance. Both EACMV-UG and ACMV were also associated with Manihot glaziovii. Infectivity studies using cloned components confirmed that viruses from one host could infect the other, suggesting that this wild relative of cassava might be a reservoir host for the disease. The relatively low level of diversity of begomoviruses associated with cassava mosaic disease in Uganda is consistent with reports that EACMV-UG has displaced other begomovirus species and strains during the recent epidemic that swept through the country.
National Crops Resources Research Institute, Namulonge, PO Box 7084, Kampala, Uganda.|Department of Disease and Stress Biology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK.
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Sserubombwe
Department of Disease and Stress Biology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK.
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Briddon
National Crops Resources Research Institute, Namulonge, PO Box 7084, Kampala, Uganda.
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Baguma
National Crops Resources Research Institute, Namulonge, PO Box 7084, Kampala, Uganda.
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Ssemakula
Department of Disease and Stress Biology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK.
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Bull
National Crops Resources Research Institute, Namulonge, PO Box 7084, Kampala, Uganda.
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Bua
National Crops Resources Research Institute, Namulonge, PO Box 7084, Kampala, Uganda.
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Alicai
National Crops Resources Research Institute, Namulonge, PO Box 7084, Kampala, Uganda.
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Omongo
National Crops Resources Research Institute, Namulonge, PO Box 7084, Kampala, Uganda.
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Otim-Nape
Department of Disease and Stress Biology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK.
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Stanley
D053839:Begomovirus / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D003001:Cloning, Molecular; D016172:DNA Fingerprinting; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D002365:Manihot / Q000821:virology*; D010802:Phylogeny; D010935:Plant Diseases / Q000821:virology*; D012150:Polymorphism, Restriction Fragment Length; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014026:Nicotiana / Q000821:virology; D014454:Uganda
D004279:DNA, Viral