Partial sequencing of putative trypsin cDNAs in Cry1Ac susceptible and resistant strains of Helicoverpa armigera (Hubner)

Insect bioassays were carried out of field strain of Helicoverpa armigera that survived on Bt cotton. These insects were reared on Cry1Ac incorporated diet that served as the initial culture for selection of resistance. Based on the partial sequences of putative trypsin mRNA of Helicoverpa armigera (accession no. AFO45138) trypsin specific primers were designed.