Incidence and genetic diversity of apple chlorotic leaf spot virus in Iran

Apple chlorotic leaf spot virus (ACLSV) is one of the most common viruses infecting apple and pear trees, and Iran is among the top ten apple-producing countries in the world. In the present study, incidence and genetic diversity of ACLSV were investigated in the main apple-growing regions of Iran. To achieve this purpose, a total of 1053 leaf samples were collected from orchards located in nine Iranian provinces. ACLSV infection was detected by DAS-ELISA in 48 samples (4.55%) from seven provinces and was confirmed by RT-PCR. Based on the geographical origin, 19 representative isolates were selected for phylogenetic analysis. Nineteen amplicons, with a size of 677 base pairs (bp), containing the 3′ end of the movement protein (MP), the coat protein (CP) gene, and 3′-UTR sequence, were sequenced. Sequence analysis, using data of 45 isolates from 12 different countries, including the 19 Iranian isolates, showed that CP gene among the Iranian isolates were 80–99% identical at both nucleotide and amino acid levels, and these isolates were placed in the B6 (AB326224) and P-205 (D14996) ACLSV groups. This is the first genetic analysis of ACLSV in Iran.