Genetics of Heliothis and Helicoverpa resistance to chemical insecticides and to Bacillus thuringiensis

✍ Scribed by Heckel, David G.; Gahan, Linda J.; Gould, Fred; Daly, Joanne C.; Trowell, Stephen

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 233 KB
• Volume: 51
• Category: Article
• ISSN: 1526-498X
• DOI: 10.1002/(sici)1096-9063(199711)51:3<251::aid-ps629>3.0.co;2-n

✦ Synopsis

Genetic linkage maps of Heliothis virescens and Helicoverpa armigera are being used to identify and characterize resistance-conferring genes. The insensitive acetylcholinesterase conferring resistance to organophosphorus insecticides and the insensitive sodium channel conferring resistance to pyrethroids have both been mapped in H. virescens. The linkage mapping approach permits a genetic dissection of resistance, even when the mode of action and lethal target are not precisely known, such as for the insecticidal toxins from the bacterium Bacillus thuringiensis (Bt). We have identiÐed and mapped a major Bt-resistance locus in a strain of H. virescens exhibiting up to 10 000-fold resistance to Cry1Ac toxin and are currently developing a linkage map for H. armigera with a set of "anchorÏ loci to facilitate comparison with H. virescens. Both species are currently experiencing their Ðrst signiÐcant selective pressure in the Ðeld by transgenic cotton expressing Cry1Ac, and timely identiÐcation of resistance mechanisms and their underlying genetic basis will be essential in successfully managing the Bt resistance that will eventually appear.