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NALDC Record Details:
Susceptibility of Cry1Ab maize-resistant and -susceptible strains of sugarcane borer (Lepidoptera: Crambidae) to four individual Cry proteins
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Sugarcane borer, Diatraea saccharalis (F.), is a major target of Bt maize in South America and many areas of the US mid-south region. Six laboratory strains of D. saccharalis were established from six single-pair F2 families possessing major resistance alleles to Cry1Ab maize hybrids. Susceptibility of the six strains was evaluated on diet treated with each of four purified trypsin-activated Bt proteins, Cry1Ab, Cry1Aa, Cry1Ac and Cry1F. Bt susceptibility of the six strains was compared with that of known Cry1Ab-susceptible and -resistant strains of D. saccharalis. At least two of the six strains demonstrated a similar level (>526-fold) of resistance to Cry1Ab as shown in the known Cry1Ab-resistant strain, while resistance levels were relatively lower for other strains (116- to 129-fold). All the six strains were highly cross-resistant to Cry1Aa (71- to 292-fold) and Cry1Ac (30- to 248-fold), but only with a low level to Cry1F (<7-fold). Larval growth of all six strains was also inhibited on Bt-treated diet, but, except for Cry1F, the growth inhibition of the six strains was considerably less than that of the Cry1Ab-susceptible larvae. The results provide clear evidence that the observed resistance to Cry1Ab maize in the six strains is a result of resistance to the Cry1Ab protein in the plants. The low level of cross-resistance between Cry1A and Cry1F suggests that pyramiding these two types of Bt proteins into a plant could be a good strategy for managing D. saccharalis.
B. Rogers Leonard
Yu Cheng Zhu
David S. Wangila
USDA Scientist Submission
Journal of invertebrate pathology March 2013 2013 March v.112
Journal Articles, USDA Authors, Peer-Reviewed
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.
Agricultural Research Service
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