First report of grapevine yellow speckle viroid-2 infecting grapevine (Vitis vinifera) in India.
In the past few years, virus and viroids have been found associated with grapevine in India, limiting the production and productivity as well as reducing the vine vigour. Three out of five viroids reported worldwide on grape have been recorded from vineyards in India, namely, Australian grapevine viroid, grapevine yellow speckle viroid-1, and hop stunt viroid, whereas there are no reports of citrus exocortis viroid and grapevine yellow speckle viroid-2 (GYSVd-2) infection from India. Leaf samples were collected from the three popular grape cultivars (Thompson Seedless, Sharad Seedless, and Flame Seedless) exhibiting yellowing, vein banding, yellow speckle, and downward curling symptoms in the glasshouse at the Indian Agricultural Research Institute New Delhi. Based on the results of polymerase chain reaction assay and BLAST analysis of the nucleotide sequences, the causal agent was identified as GYSVd-2. This virus was previously reported from Australia, China and Thailand and produces foliar yellow speckle symptoms. This is thought to be the first report of GYSVd-2 in India.