Presence of Citrus tristeza virus in Angola and São Tomé e Princípe: characterization of isolates based on coat protein gene analysis

A first report is given of the presence of Citrus tristeza virus (CTV) in Angola and Sao Tome e Principe. Two out of twenty citrus samples from Sao Tome e Principe and all of the seven samples from Angola were shown by ELISA to contain CTV. The capsid protein gene variants obtained by IC/RT-PCR were characterized by SSCP analysis to test for the presence of different haplotypes in each isolate and nucleotide sequence analysis of each variant leading to a different SSCP pattern, followed by in silico comparison with previously characterized CTV groups. The results confirmed that each isolate could contain different variants, which clustered with the different groups. Variants obtained from each country fitted into the same three clusters