DISTRIBUTION AND GENETIC DIVERSITY OF TOMATO MOSAIC VIRUS ISOLATES IN IRAN

The host range and genetic variability of Tomato mosaic virus (ToMV) from Iran were investigated using isolates from different vegetables and chenopodiaceous weeds collected from 10 Iranian provinces. Of 849 symptomatic vegetables and 45 asymptomatic chenopodiaceous weeds sampled, 85 different vegetables and three nettle-leaf goosefoot (Chenopodium murale L.) samples were infected with ToMV, as indicated by DAS-ELISA. Analysis of the biological properties of selected ToMV isolates revealed three pathological groups, indicating the presence of different ToMV populations in Iran. Iranian isolates NL93 and NO1, belonging to group II, did not infect solanaceous plants whereas four other Iranian ToMV isolates along with other global isolates in group I mostly infected the solanaceous host species tested. Phylogenetic analyses of the complete ToMV coat protein open reading frame sequences indicated two clades on the basis of nucleotide and deduced amino acid sequences, and suggested the genetic relationship between isolates from various geographic origin due to the exchange of infected plant materials between Asian countries. The broad diversity of Iranian ToMV isolates showed that the ToMV populations in Iran consist of several strains that have high nucleotide diversity.