Tamil Nadu Agricultural University, Coimbatore-641003, India.
Abstracts of the papers presented at the International Conference of Indian Virological Society on “Emerging and Re-emerging viral Diseases of the Tropics and Subtropics” at Indian Agricultural Research Institute, New Delhi, India, December 11–14, 2007.
Wide variations in the symptoms of tomato leaf curl disease were observed in Ciombatore district of Tamil Nadu. Two isolates of Tomato leaf curl virus (ToLCV) that produced distinct symptoms consistently on tomato upon artificial inoculation were selected to study their sequence diversity. Isolate 1 produced mild leaf curl with interveinal chlorosis while Isolate 2 lead to severe leaf curl, chlorosis, reduced leaf size, thickened veins followed by stunted growth. Deng's degenerate primers and coat protein (CP) primers enabled the amplification of 531 bp and 874 bp long DNA fragments from ToLCV infected samples through polymerase chain reaction. PCR products obtained using Deng's and CP primers were cloned and sequenced. The nucleotide and deduced amino acid sequences of ORF AV2 of isolate 1 and 2 shared 94.8 and 95.6 per cent identity respectively. ORF AV1 of the isolate 1 and 2 exhibited 93.3 and 94.5 per cent similarity at nucleotide and amino acid level respectively. Phylograms constructed using ORF AV1 and AV2 sequences placed both the isolates under investigation with Tomato leaf curl Bangalore virus from Karnataka.
