Incidence and Molecular Analysis of Potato leafroll virus in Iran

Potato leafroll virus (PLRV) is one of the most prevalent potato viruses in Iran. This report describes the distribution of PLRV in four Provinces from south-eastern, southern, north-eastern and north-western Iran and phylogenic relationships of Iranian PLRV to other previously reported PLRV isolates. PLRV was detected in c.15% (126 of 836) of symptomatic potato samples (showing yellowing and leaf roll) by double antibody sandwich enzyme-linked immunosorbent assay. The coat protein (CP) gene of four isolates was amplified by reverse transcription-polymerase chain reaction using specific primers. The nucleotide sequence showed a high degree of sequence identities between all PLRV isolates. Three of the four Iranian isolates were 100% identical at the amino acid level (for the domain sequenced), but the fourth isolate differed by an amino acid. For isolate PLRV-Ke, we amplified the open reading frame (ORF0) (which overlaps the 5' end of the ORF1) and the sequence analysis indicated that the amino acid sequences of the ORF0 and the 5' end of the ORF1 showed identity of 92.7-100% and 90.2-99% with that of the GenBank PLRV isolates, respectively. In contrast to the amino acid sequence of the CP, a constructed phylogenetic tree using the amino acid sequence of the ORF0 differentiated the Iranian isolate (PLRV-Ke) from some European and African isolates.