Genetic analysis of maize streak virus isolates from Uganda reveals widespread distribution of a recombinant variant.
Maize streak virus (MSV) contributes significantly to the problem of extremely low African maize yields. Whilst a diverse range of MSV and MSV-like viruses are endemic in sub-Saharan Africa and neighbouring islands, only a single group of maize-adapted variants - MSV subtypes A(1)-A(6) - causes severe enough disease in maize to influence yields substantially. In order to assist in designing effective strategies to control MSV in maize, a large survey covering 155 locations was conducted to assess the diversity, distribution and genetic characteristics of the Ugandan MSV-A population. PCR-restriction fragment-length polymorphism analyses of 391 virus isolates identified 49 genetic variants. Sixty-two full-genome sequences were determined, 52 of which were detectably recombinant. All but two recombinants contained predominantly MSV-A(1)-like sequences. Of the ten distinct recombination events observed, seven involved inter-MSV-A subtype recombination and three involved intra-MSV-A(1) recombination. One of the intra-MSV-A(1) recombinants, designated MSV-A(1)UgIII, accounted for >60 % of all MSV infections sampled throughout Uganda. Although recombination may be an important factor in the emergence of novel geminivirus variants, it is demonstrated that its characteristics in MSV are quite different from those observed in related African cassava-infecting geminivirus species.
Owor
Betty E
BE
Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch 7701, South Africa.
Martin
Darren P
DP
Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Anzio Rd, Observatory 7925, South Africa.
Shepherd
Dionne N
DN
Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch 7701, South Africa.
Edema
Richard
R
Department of Crop Science, Faculty of Agriculture, Makerere University, PO Box 7062, Kampala, Uganda.
Monjane
Adérito L
AL
Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch 7701, South Africa.
Rybicki
Edward P
EP
Electron Microscope Unit, University of Cape Town, Private Bag, Rondebosch 7701, South Africa.|Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch 7701, South Africa.
Thomson
Jennifer A
JA
Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch 7701, South Africa.
Varsani
Arvind
A
Electron Microscope Unit, University of Cape Town, Private Bag, Rondebosch 7701, South Africa.|Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch 7701, South Africa.
D001483:Base Sequence; D016172:DNA Fingerprinting; D019143:Evolution, Molecular; D016679:Genome, Viral / Q000235:genetics; D005838:Genotype; D026762:Maize streak virus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000821:virology*; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014454:Uganda; D003313:Zea mays / Q000821:virology*