Complete nucleotide sequence of a DNA virus isolated from Vitis vinifera in India: A symptomless host of Grapevine red blotch virus
Avinash Marwal: Mody University of Science and Technology
<div>Symptomless grape plants ( <em>Vitis vinifera</em>) were found to be anchoring a Grapevine red blotch virus (GRBV) in Punjab province of India. Full length DNA sequence component of the virus was cloned and determined (KU522121; 3,204 bp), showing similarity with monopartite mastrevirus, begomovirus and other Grapevine red-blotch associated virus reported from US and Canada. A series of experiments were performed to identify any possible mixed infections by other members of <em>Geminiviridae</em> family, which were tends to be negative. Assessing infectivity of the cloned virus and symptoms it induces in plants, full-length construct were produced and agroinfiltrated to 15 plants each from <em>Chenopodium album</em>, <em>Lycopersicon esculentum </em>and <em>Vitis vinifera</em> and five plants from each species were taken as negative (not inoculated with the construct). Following agroinfiltration, plants were incubated in a growth chamber at 25 <sup>O</sup>C and symptoms were allowed to develop for 2–4 weeks with regular monitoring. None of the experimented plants developed any observable disease symptoms. When no symptoms appeared at the end of four weeks, plants were assayed (old as well as young leaves under investigation) for virus occurrence by PCR diagnostics, with the help of primers designed for KU522121. All the sample plants were positive for geminivirus infection despite the lack of symptoms. This species of Grapevine red-blotch virus might not be well adapted to Indian <em>Vitis vinifera</em>, suggesting it as a reason for symptomless temperament. To our knowledge this is the first report of a symptomless host <em>Vitis vinifera</em> harbouring a Grapevine geminivirus from Indian vineyards.</div>
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