Preliminary Study on Insecticidal Activity of Transgenic Corn Expressing Bt Insecticidal Protein Gene to Helicoverpa armigera Hübner

Insecticidal activity of different organs of transgenic corn expressing Cry1Ab insecticidal protein gene from B acillus thuringiensis(Bt) to H elicoverpa armigera was tested inlaboratory. The results showed that popcorn has the lowest activity among the 7 organs of Bt corn, and the order of insecticidal activity was as follows: popcorn < filament < stem < corncob < bract < corn-grain < leaf. There was significant difference of insecticidal activity of filament to Cry1Ac-resistant population (13.1-fold of resistance ratio) compared with that of a susceptible population of the pest.