Browsing by Subject "Plant viruses"

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    Molecular biological studies of Southern African isolates of maize streak virus
    (1987) Clarke, Beverley A; Dr E.P. Rybicki
    This thesis deals with an investigation of the nature of variation of maize streak virus (MSV) isolates in Southern Africa. Three isolates from distinct geographical locations, which produced different symptoms, were chosen for this purpose. Serological tests performed with antisera raised to two of the isolates showed the three isolates to be serologically related but non-identical. This relationship was further verified by cloning and restriction endonuclease mapping of the genomes of the isolates. These maps were then compared to those of published MSV isolates, revealing both similarities and differences. The predicted and experimental restrict ion patterns were used to construct a phylogenetic tree of all the MSV isolates so far characterised at the genomic leve 1. A fourth geminivirus (DGV) which infects the grass Digitaria sanguinalis, was compared to known isolates of MSV in order to confirm its identification as an MSV strain: DGV was only distantly serologically related to Southern African MSVs, and is probably a distinct virus.