Molecular Virology, Mahyco Research Center, Post Box No. 76, Dawalwadi, Jalna, Maharashtra-431 203, India.
Abstracts of the papers presented at the XVIII National Conference of Indian Virological Society at Post Graduate Institute of Medical Education and Research, Chandigarh, India, December 11–13, 2008.
During the survey in various districts of Haryana and Uttar Pradesh for Tospoviruses in vegetable crops, the tomato and chilli leaves showed the symptoms mimicking those caused by Peanut bud necrosis virus. On tomato, the symptoms included mild chlorosis of leaves, chlorotic and necrotic spots and rings on the leaves, where as chilli leaves showed mild chlorosis and chlorotic lesions. Mechanical inoculation of sap from symptomatic tomato and chilli leaves produced local chlorotic spots on Vigna unguiculata 3 to 4 days post inoculation. Tomato seedlings inoculated with the same infected crude sap produced chlorotic lesions on leaves, which later turned necrotic, whereas chilli seedlings inoculated with sap produced chlorotic spots leading to severe leaf chlorosis. The electron microscopic study revealed quasi-spherical virions enclosed in a membranous envelope. In direct antigen coating ELISA, both field as well as mechanically inoculated plant samples reacted positive to polyclonal antiserum produced against the nucleocapsid (N) protein of PBNV. The N gene of isolates from tomato (EU095940) and chilli (EU373799) was cloned and sequenced. Their comparative analysis with corresponding N gene sequences revealed more than 95% identity with Capsicum chlorosis virus (CaCV) (AY036057) from Australia at nucleotide and amino acid level. In host range studies, the CaCV infected various plant species belonging to family Amaranthaceae, Apocynaceae, Chenopodiaceae, Fabaceae and Solanaceae. India is the second largest producer of vegatables in the world. The incidence of CaCV on tomato and chilli warrants further studies for developing crop improvement strategies in India.
