Abstract: The 2.5 kb fragment of enhancin gene in 3' terminal from Trichoplusia ni granulosis virus was inserted into vector pQE-31 and expressed successfully in Escherichia coli M15 (pREP4). The synergy of the expression product (P96) on Helicoverpa armigera nuclear polyhedrosis virus (HaNPV) against the 3rd instar larvae of H. armigera was also studied. The results indicated that the percentage of accumulated mortality of the larvae increased by 27.40%～34.50% on the 11th day postinfection and the median lethal time decreased at least by 1.9 days in HaNPV+P96 treated compared with those in HaNPV treated.

Key words: Trichoplusia ni granulosis virus, enhancin gene, cloning, expression, bioassay