Abstract: The chitinase gene of Helicoverpa armigera single enveloped nucleocapsid nucleopolyhedrovirus (HaSNPV) was amplified by using PCR method. The nucleotide sequence of the coding region was determined. The total length of the coding region was 1.713 bp and was potential to encode a 570 amino acid polypeptide with predicted molecular weight of 636 kD. The alignment of HaSNPV chitinase amino acid sequence with those of other 7 reported baculovirus chitinases showed that HaSNPV chitinase was most closely related to HzSNPV chitinase, with 90.7% amino acid identity. It also shared a high degree of homology with chitinases of AcMNPV, BmNPV, HcNPV, LdMNPV, OpMNPV and CfMNPV, with 64.4%, 64.9%、64.2%、62.9%、66.2% and 61.5% amino acid identity, respectively. A phylogenetic tree of 8 baculovirus chitinases was drawn by using PC＼GENE program, and compared with the phylogenetic tree based on the polyhedrin amino acid sequences of the same 8 baculoviruses. The result showed that the evolutionary rate of chitinase genes was in some degree different to that of polyhedrin genes.

Key words: Helicoverpa armigera nucleopolyhedrovirus, chitinase gene, nucleotide sequence, baculovirus, phylogenetic tree