Geographic distribution and phylogenetic analysis of cucurbit yellow stunting disorder virus in Iran

Abstract

Cucurbit yellow stunting disorder virus (CYSDV) is a destructive virus of cucurbits in Iran. During 2008-2012 growing seasons a total of 366 cucurbit samples including melon, cucumber, snakemelon and squash with typical symptoms of CYSDV infection were collected from ten Provinces in Iran. They were screened by ELISA and the infectivity of ELISA-positive samples was confirmed by RT-PCR. The results showed that 309 out of 366 samples were infected by CYSDV. The virus was present in many areas of southern and central Provinces of the country. Analyses of nucleotide and amino acid sequences of the CYSDV coat protein (CP) showed that Iranian isolates form a cluster and were placed in the Eastern subgroup of CYSDV. The Eastern subgroup of CYSDV was divided into two diverged subgroups including Iranian isolates and Saudi Arabian isolates. The identity among Iranian isolates was more than 99 %. Estimation of genetic distances showed that the number of nucleotide and amino acid substitutions per site from averaging overall Iranian sequence pairs were 0.004 and 0.008, respectively. Phylogenetic analyses and the estimation of genetic distance indicated that Iranian isolates have low genetic diversity.