Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: Insecticide Resistance Management and New Control Strategies for Pests of Corn, Cotton, Sorghum, Soybean, and Sweet Potato

Location: Southern Insect Management Research Unit

Title: Susceptibility of Cry1Ab maize-resistant and –susceptible strains of sugarcane borer (Lepidoptera: Crambidae) to four individual Cry proteins

Authors
item Zhang, Liping -
item Huang, Fangneng -
item Leonard, Rogers -
item Chen, Mao -
item Clark, Thomas -
item Zhu, Yu Cheng
item Wangila, David -
item Yang, Fei -
item Niu, Ying -

Submitted to: Journal of Invertebrate Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 15, 2012
Publication Date: March 1, 2013
Repository URL: http://handle.nal.usda.gov/10113/56896
Citation: Zhang, L., Huang, F., Leonard, R., Chen, M., Clark, T., Zhu, Y., Wangila, D., Yang, F., Niu, Y. 2013. Susceptibility of Cry1Ab maize-resistant and –susceptible strains of sugarcane borer (Lepidoptera: Crambidae) to four individual Cry proteins. Journal of Invertebrate Pathology. 112(3):267-272.

Interpretive Summary: Sugarcane borer is a major target of Bt corn in South America and many areas of the U.S. mid-south region. Six laboratory strains of sugarcane borer were established from six single-pair mating families possessing major resistance gene alleles to Cry1Ab corn hybrids. Susceptibility of the six strains was evaluated on diet treated with each of four purified 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 the sugarcane borer. 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 corn 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 sugarcane borer.

Technical Abstract: Sugarcane borer, Diatraea saccharalis (F.), is a major target of Bt maize in South America and many areas of the U.S. 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.

Last Modified: 10/21/2014
Footer Content Back to Top of Page