Serological and Molecular Identification of Tobacco streak ilarvirus Infecting Onion (Allium cepa L.) on Commercial Fields in SouthernIndia

摘要

Tobacco streak virus (TSV), a member of the genus Ilarvirus (family: Bromoviridae) is an important viral pathogen infecting onion in Southern India. TSV isolates naturally infecting onion plants were collected from Andhra Pradesh, Tamil Nadu and Karnataka States in South India and characterized. The TSV infection was confirmed by direct antigen coating enzyme linked immunosorbent assay (DAC-ELISA)usingTSVantiserum.The CP gene was further amplified by using TSV coat protein primers. The amplicon (717bp) was cloned, sequenced and sequence analysis revealed that the N gene shared 98.6-100 and 98.3-100% sequence identity with TSV at the nucleotide and aminoacid levels, respectively. The phylogenetic relation based on the sequence of these isolates fromdifferent geographical regions was also analyzed in this study.