MOLECULAR IDENTIFICATION OF CUCUMBER MOSAIC VIRUS SUBGROUP IB ISOLATES IN SOUTH IRAN
S. Farzadfar, R. Pourrahim, N. Arafati
Cucumber mosaic virus (CMV) is one of the most widespread plant viruses in the world. In the present study tomato fields in Minab and Varamin counties of the Iranian Hormozgan and Tehran provinces, respectively were surveyed for CMV presence during 2011-2012. Fifty eight out of 95 samples tested (61%) were found to be infected with CMV. Nicotiana glutinosa and Solanum lycopersicum reacted with more severe symptoms to Varamin than Minab viral isolates. Phylogenetic analysis of the coat protein (CP) gene showed five CMV Varamin isolates and most of the previously reported CMV isolates from northwest Iran as well as CMV-Cu (Genbank accession No. EF620777) in subgroup IA, whereas four Minab isolates fell into subgroup IB with the highest identity (97.2-98.7%) to the Greek isolates G2 and G10. Using the Maximum likelihood (ML) method, amino acids 25, 30, and 204 in the CP gene of Iranian CMV isolates were found under positive selection, although the likelihood-ratio test (LRT) statistics for aa 25 and 204 were not significant. This study shows for the first time the occurrence and phylogenetic relationships of CMV subgroup IB isolates in west Asia.