Development of resistance to eCry3.1Ab-expressing transgenic maize in a laboratory-selected population of western corn rootworm (Coleoptera: Chrysomelidae).
A laboratory colony of western corn rootworm, Diabrotica virgifera virgifera LeConte, was selected for resistance to transgenic maize expressing the eCry3.1Ab protein. The selected colony was developed by rearing larvae on nonelite noncommercial Bt maize expressing the eCry3.1Ab protein. After four generations, selected and control colonies were screened on eCry3.1Ab-expressing and isoline maize using greenhouse experiments. There was a significant colony x maize pedigree interaction in terms of the number of larvae recovered. There was no significant difference in the number of larvae recovered from eCry3.1Ab-expressing and isoline maize for the selected colony, whereas this difference was significant for the control colony. There was not a significant colony x maize pedigree interaction in terms of root damage, or the number of beetles recovered, but the effect of maize pedigree was significant. After four and eight generations of selection, seedling bioassays were performed. Again, there was a significant colony x maize pedigree interaction in terms of the number of larvae recovered. After 11 generations of selection, larvae from the selected colony had higher LC50 values than the control colony when exposed to increasing concentrations of the eCry3.1Ab protein. The resistance ratio of the selected colony was 2.58. These data provide necessary information for understanding the potential for Bt resistance by western corn rootworm and underscores the need for insect resistance management plans for this pest.
West Virginia University, Extension Service, Agriculture and Natural Resources Unit, Agricultural Sciences Bldg., P.O. Box 6108, Morgantown, WV 26506, USA. dlfrank@mail.wvu.edu
Daniel L
DL
Frank
USDA-ARS, Plant Genetics Research Unit, 205 Curtis Hall, University of Missouri, Columbia, MO 65211, USA.
Anthony
A
Zukoff
USDA-ARS, Plant Genetics Research Unit, 205 Curtis Hall, University of Missouri, Columbia, MO 65211, USA.
Julie
J
Barry
USDA-ARS, Plant Genetics Research Unit, 205 Curtis Hall, University of Missouri, Columbia, MO 65211, USA.
Matthew L
ML
Higdon
USDA-ARS, Plant Genetics Research Unit, 205 Curtis Hall, University of Missouri, Columbia, MO 65211, USA.
Bruce E
BE
Hibbard
D000818:Animals; D001413:Bacillus thuringiensis / Q000235:genetics; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics / Q000633:toxicity; D001517:Coleoptera / Q000235:genetics* / Q000254:growth & development* / Q000502:physiology; D004731:Endotoxins / Q000235:genetics / Q000633:toxicity; D005260:Female; D006460:Hemolysin Proteins / Q000235:genetics / Q000633:toxicity; D007305:Insecticide Resistance; D007306:Insecticides; D007814:Larva / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D008297:Male; D010572:Pest Control, Biological; D018517:Plant Roots / Q000633:toxicity; D030821:Plants, Genetically Modified / Q000633:toxicity*; D012641:Selection, Genetic; D003313:Zea mays / Q000235:genetics / Q000633:toxicity*
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; D007306:Insecticides; C030956:insecticidal crystal protein, Bacillus Thuringiensis