Detection and Variability of Begomoviruses in Tomato from the Andean States of Venezuela

The three Andean states of Mérida, Táchira, and Trujillo in Venezuela produce tomatoes (Lycopersicon esculentum) year-round with a high frequency of virus-like symptoms. Polymerase chain reaction amplification using degenerate primers detected begomoviruses in 18% of leaf samples collected from tomato plants showing virus-like symptoms in commercial fields in these states between 1993 and 1994. A comparison of the sequences of the amplified DNA products revealed a diversity of begomovirus sequences in tomato plants from this region. Partial A component sequences (approximately 1,100 bp) clustered in four groups based on BLAST, GAP, phylogenetic analyses of the nucleic acid sequences, and comparisons of iteron sequences with known begomoviruses. Two groups of sequences were closely related to Potato yellow mosaic virus—Venezuela strain tomato and Tomato Venezuela virus, respectively, begomoviruses previously reported from other Venezuelan states. The other two groups of sequences appear to belong to two new begomovirus species.