Epidemiological situation of Citrus tristeza virus in mainland Portugal

Abstract

This study was conducted to update the occurrence and molecular variability of Citrus tristeza virus (CTV) isolates recently obtained from surveys in different orchards in mainland Portugal. The asymmetric PCRELISA typing method based on the coat protein (CP) gene was used to characterize CTV isolates. Most isolates of the virus found in the Algarve region, where major citrus producing zones exist, belonged to the mild phylogenetic group (GpM). The prevalence of haplotypes from this group suggests that the aphid vector Toxoptera citricidus, which is present in the northern region of the country associated to diverse severe strains, has not yet reached the Algarve. Although most of the isolates harbour haplotypes from group M, haplotypes from the remaining phylogenetic groups were also identified and characterized.