TY - JOUR
T1 - Inheritance of resistance to Bt toxin crylac in a field-derived strain of pink bollworm (Lepidoptera
T2 - Gelechiidae).
AU - Tabashnik, Bruce E.
AU - Liu, Yong Biao
AU - Dennehy, Timothy J.
AU - Sims, Maria A.
AU - Sisterson, Mark S.
AU - Biggs, Robert W.
AU - Carrière, Yves
PY - 2002/10
Y1 - 2002/10
N2 - Laboratory selection with Cry1Ac, the Bacillus thuringiensis (Bt) toxin in transgenic cotton, initially produced 300-fold resistance in a field-derived strain of pink bollworm, Pectinophora gossypiella (Saunders), a major cotton pest. After additional selection increased resistance to 3,100-fold, we tested the offspring of various crosses to determine the mode of inheritance of resistance to Cry1Ac. The progeny of reciprocal F1 crosses (resistant male x susceptible female and vice versa) responded alike in bioassays, indicating autosomal inheritance. Consistent with earlier findings, resistance was recessive at a high concentration of Cry1Ac. However, the dominance of resistance increased as the concentration of Cry1Ac decreased. Analysis of survival and growth of progeny from backcrosses (F1 x resistant strain) suggest that resistance was controlled primarily by one or a few major loci. The progression of resistance from 300- to 3,100-fold rules out the simplest model with one locus and two alleles. Overall the patterns observed can be explained by either a single resistance gene with three or more alleles or by more than one resistance gene. The pink bollworm resistance to Cry1Ac described here fits "mode 1" resistance, the most common type of resistance to Cry1A toxins in Lepidoptera.
AB - Laboratory selection with Cry1Ac, the Bacillus thuringiensis (Bt) toxin in transgenic cotton, initially produced 300-fold resistance in a field-derived strain of pink bollworm, Pectinophora gossypiella (Saunders), a major cotton pest. After additional selection increased resistance to 3,100-fold, we tested the offspring of various crosses to determine the mode of inheritance of resistance to Cry1Ac. The progeny of reciprocal F1 crosses (resistant male x susceptible female and vice versa) responded alike in bioassays, indicating autosomal inheritance. Consistent with earlier findings, resistance was recessive at a high concentration of Cry1Ac. However, the dominance of resistance increased as the concentration of Cry1Ac decreased. Analysis of survival and growth of progeny from backcrosses (F1 x resistant strain) suggest that resistance was controlled primarily by one or a few major loci. The progression of resistance from 300- to 3,100-fold rules out the simplest model with one locus and two alleles. Overall the patterns observed can be explained by either a single resistance gene with three or more alleles or by more than one resistance gene. The pink bollworm resistance to Cry1Ac described here fits "mode 1" resistance, the most common type of resistance to Cry1A toxins in Lepidoptera.
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U2 - 10.1093/jee/95.5.1018
DO - 10.1093/jee/95.5.1018
M3 - Article
C2 - 12403429
SN - 0022-0493
VL - 95
SP - 1018
EP - 1026
JO - Journal of economic entomology
JF - Journal of economic entomology
IS - 5
ER -