Molecular Characterization of Begomoviruses Causing Tobacco Leaf Curl Diseasein different Parts of Karnataka

摘要

Molecular characterization of the 6 different isolates from major tobacco growing areas of Karnataka through sequencing of 1.2kb amplicon corresponding to 4 major genes viz., coat protein (AVI) gene and replication initiation (AC1) gene partial, replication enhancer gene (AC3) and transcription activator gene (AC2) complete. The obtained sequences were subjected to NCBI BLAST search. TbLCV isolates from Davanagere, Mysuru and Belagavi showed 91 per cent of sequence similarity with the tomato leaf curl Karnataka virus (KX219744.1), tomato leaf curl Katnataka virus-Bangalore isolate (FJ514798.1) and Tomato leaf curl Joydebpur virus (DQ673 859.1), respectively. Mandya and Shivamogga isolates showed 91 per cent of sequence similarity with Indian cassavamosaic virus (Z24758.1) and Indian cassava mosaic virus strain Salem (KU550960.1), respectively. Whereas, Chamarajanagar isolate showed 87 per cent sequence similarity with tobacco leaf curl Thailand virus (DQ871221.1). Phylogenetic analysis of these isolates revealed that, they formed 3 clusters, wherein Davanagere, Mysuru and Belagavi were grouped in one cluster showing highest sequence similarity with the Tomato leaf curl virus (ToLCV), Mandya and Shivamogga formed another cluster with Indian cassava mosaic virus (ICMV). Chamarajanagar isolate formed a separate cluster with Tobacco leaf curl Thailand virus (TbLCTV-Thailand). This is the first report of association of three begomoviruses with the TbLCV disease in Karnataka.