Comparison of polyhedrin partial sequence of NPV variants pathogenic to tea pests (Geometridae) in India and their phylogeny

ABSTRACT

Aim: The present study was undertaken to understand the phylogenetic relationships of NPVs (Nucleopolyhedroviruses) isolated from two pest species, Hyposidra talaca and Biston (=Buzura) suppressaria. The phylogenetic analyses based on the polyhedrin gene were assessed. Methodology: Occlusion bodies (OBs) were isolated separately from NPV infected dead Hyposidra talaca and Buzura suppressaria larvae, and DNA was isolated from OBs. The polyhedrin gene was amplified and sequenced followed by sequence divergence and phylogenetic analyses using MEGA5. Results: The phylogenetic analyses based on the polyhedrin gene revealed that the NPV isolated from Hyposidra talaca (HytaNPV-ITK1) formed a single cluster with the isolates of NPVs infecting Hyposidra specimens in India sharing 99% nucleotide identity, whereas the NPV isolated from Buzura suppressaria (BusuNPV-ITK1) showing 99% nucleotide homology with the NPV isolate of B. suppressaria reported from China formed a different cluster. A nucleotide identity of 85% was found between HytaNPV-ITK1 and BusuNPV-ITK1. Interpretation: Phylogenetic analyses, based on the polyhedrin sequence of 47 baculoviruses, revealed that these two variants of NPVs (HytaNPV-ITK1 and BusuNPV-ITK1) infecting Hyposidra talaca and Buzura suppressaria were comparatively closer to each other than those infecting specimens of other lepidopteran genera.