First report of Grapevine virus D (GVD) in Iran

Most virus members of the Vitivirus genus have been isolated from grapevine (Vitis vinifera), among which Grapevine virus A (GVA), Grapevine virus B (GVB) and Grapevine virus E (GVE) have been reported from Iranian vineyards (1, 2, 3). In this study, the occurrence of Grapevine virus D (GVD) has been reported from Iran. During a survey in 2017, a total number of 33 symptomatic samples were collected from grapevines showing leaf mottling, stem deformations and color change of stem tissue in Azarbaijanegharbi province. Total RNA was extracted from leaf petiole and primary veins and was tested for the presence of GVD by RTPCR using primers specific to the coat protein gene of GVD (4). A DNA fragment with the expected size of 470 bp was amplified from three samples. The amplified DNA fragments of two samples (IrnAzW7 and IrnAzW23) were purified and their nucleotide sequence were determined. The nucleotide sequence obtained from PCR amplicons was submitted in the GenBank under accession numbers MT133689 and MT152314 and was subjected to BLASTn analysis (available at NCBI) to confirm the identity of the target virus. The Iranian isolates showed 94.3 % nucleotide sequence identity with a GVD isolate from Italy (Ac.No. Y07764) and 92 % with a GVD isolate from Turkey (Ac.No. KY689027). GVD has been reported from Italy, Tunisia, Turkey, Croatia in Europe, and Brazil in South America (4, 5, 6). To our knowledge, this is the first report on the occurrence of GVD in Iran.