Detection of tobacco streak virus by immunocapture-reverse transcriptase-polymerase chain reaction and molecular variability analysis of a part of RNA3 of sunflower, gherkin, and pumpkin from Andhra Pradesh, India.

Abstract

The coat protein-coding and 3 0 UTR regions of the RNA3 of Tobacco streak virus infecting sunflower, gherkin, and pumpkin with the characteristic symptoms of necrosis were amplified by IC-RT-PCR. The amplicons were cloned and sequenced. The nucleotide sequences of TSV clones were determined as 1 kb. This length corresponds to 717 and 288 nucleotides of coat protein-coding and 3 0 UTR regions, respectively. Comparative sequence analysis of the coat protein-coding region of TSV isolates under study both at the nucleotide and the amino acid levels indicated 98 1% and 97 1% identity, respectively, with TSV reported from other hosts. The sequence analysis of the 3 0 UTR region at the nucleotide level showed 98 1% and 88% identities with the Indian and US isolates, respectively. IC-RT-PCR was found to be more sensitive than RT-PCR, and hence could be used in quarantine programmes.