Search results for "Bt maize"
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Cross-resistance and mechanism of resistance to Cry1Ab toxin from Bacillus thuringiensis in a field-derived strain of European corn borer, Ostrinia n…
2011
The cross-resistance spectrum and biochemical mechanism of resistance to the Bacillus thuringiensis Cry1Ab toxin was studied in a field-derived strain of Ostrinia nubilalis (Hubner) (Lepidoptera: Crambidae) that was further selected in the laboratory for high levels (>1000-fold) of resistance to Cry1Ab. The resistant strain exhibited high levels of cross-resistance to Cry1Ac and Cry1Aa but only low levels of cross-resistance (<4-fold) to Cry1F. In addition, there was no significant difference between the levels of resistance to full-length and trypsin-activated Cry1Ab protein. No differences in activity of luminal gut proteases or altered proteolytic processing of the toxin were observed in…
Evaluating resistance to Bt Toxin Cry1Ab by F-2 Screen in European populations of Ostrinia nubilalis (Lepidoptera: Crambidae)
2010
The large-scale cultivation of transgenic crops producing Bacillus thuringiensis (Bt) toxins have already lead to the evolution of Bt resistance in some pest populations targeted by these crops. We used the F2 screening method for further estimating the frequency of resistance alleles of the European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), to Bt maize, Zea mays L., producing the Cry1Ab toxin. In France, Germany, and Italy, 784, 455, and 80 lines of European corn borer were screened for resistance to Mon810 maize, respectively. In Slovakia, 26 lines were screened for resistance to the Cry1Ab toxin. The cost of F2 screen performed in the four countries varied from U.…