ABSTRACT

Dow AgroSciences, LLC has genetically modified cotton (Gossypium hirsutum L.) to express two separate insecticidal crys-tal proteins from the bacterium Bacillus thuringiensis (Bt) for the control of key lepidopteran pests. Cotton genotype GC510 was transformed to contain the genes that express full-length synthetic protoxins (synpro) of Cry1F or Cry1Ac. Transgenic lines were backcrossed with a non-transgenic elite variety, PSC-355. Subsequently, Cry1F(synpro) and Cry1Ac(synpro) lines were crossed to produce the stacked product, MXB-13. Dow AgroSciences transgenic cotton event MXB-13 provided excellent control of cotton bollworm (Helicoverpa zea [Boddie]) and tobacco budworm (Heliothis virescens[F.]), as it was demonstrated by the percent damaged terminals, damaged squares and bolls, the presence of lepidopterous larvae in Bt and non-Bt cotton, and yields.