Construction of Helicoverpa armigera Library During Latent Periods by Nuclear Polyhedrovirus cDNA Polym erase Chain Reaction

A general cDNA library which was from infected larvae dueing the latent periods has been constructed. The first cDNA strand was synthesized from total RNA by M MLV transcriptase. After oligo(dG) tailing the cDNA was amplified by polymerase chain reaction. The double strands cDNA were ligated to pGEM T easy vectors. Screeing of cDNA library showed that the length of inserts was from 0.3 to 1.1 kilobases. The capacity of cDNA library was 1.6610 5 clones. Moreover, the number of cDNA clones of HaNPV was more than 50%.