Direct Application of the New PCR Protocol for Evaluation and Monitoring of Bombyx Mori Infection by Nucleopolyhedrovirus

Abstract

Polymerase chain reaction (PCR) with complementary primers to the polyhedrin gene region was used to diagnose B. mori nucleopolyhedrovirus (BmNPV) infection. Experimental infections were performed for the standardization of the PCR assay. The PCR products were sequenced and specificity of the amplification was confirmed by comparison with BmNPV nucleotide sequences available in the GenBank. An identity level of about 99% was observed for those PCR products when compared to the known BmNPV sequences. The viral gene fragment amplification protocol proposed here is useful for early diagnosis of nucleopolyhedrosis in whole larvae, hemolymph, and infected eggs or in asymptomatic insects. Moreover, the standardized PCR can be used as a tool for surveillance and control of nucleopolyhedrosis in silkworm rearing.