Transgenic crops producing insecticidal toxins from Bacillus thuringiensis (Bt) have been widely used for pest control. Bt-resistant insect strains have been studied but the molecular basis of resistance has remained elusive. We have discovered that disruption of a cadherin-superfamily gene by retrotransposon-mediated insertion is linked to high levels of Cry1Ac toxin resistance in the cotton pest Heliothis virescens. Monitoring the early phases of Bt resistance evolution in the field has been viewed as crucial but extremely difficult, especially when resistance is recessive. Our findings enable efficient DNA-based screening for resistant heterozygotes by directly detecting the recessive allele.
Species 1: Lepidoptera Noctuidae Heliothis virescens (tobacco budworm)
Keywords: resistance monitoring
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA