Diversity of the coat protein gene of Citrus tristeza virus in the Mediterranean region

Sequence data of the coat protein gene of CTV were retrieved from the GenBank or from tested infected tissues and compiled. A comparison with a compartable set of sequences from worldwide isolates showed a very simmilar value for the nucleotide diversity and a very similar genetic structure in which the same seven groups of variants are conspicuous. A geographic speciation is not apparent and, probably, differences in the distribution of CTV groups are a result of trade. In countries that usually import propagating material from Spain, the group M predominates while group 3b predominates in countries that import material from Israel.