Behaviour of laboratory-selected Cry1Ac-tolerant strain of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) on Bt-cotton
نویسندگان
چکیده
The effect of Bacillus thuringiensis toxin Cry1Ac on the behaviour of a laboratory-selected resistant population (72-fold) of Helicoverpa armigera on Bt-cotton was evaluated. Compared with non-Bt-cotton and Cry1Ac toxin incorporated in semi-synthetic diet, resistant larvae reared on Bt-cotton had only 0.13% survival and slower development. The results suggest that Cry1Ac from Bt-cotton exerts a greater toxic effect in terms of larval mortality coupled with decline in larval growth rate compared to semi-synthetic diet.
منابع مشابه
Evidence of field-evolved resistance to Cry1Ac-expressing Bt cotton in Helicoverpa armigera (Lepidoptera: Noctuidae) in northern China.
BACKGROUND Evolution of resistance threatens the continued success of transgenic crops expressing insecticidal proteins. One of the key factors for successful resistance management is the timely implementation of monitoring programmes to detect early changes of resistance allele frequency in field populations. F(1)/F(2) screen, dose-response bioassays and field survey were used to monitor resis...
متن کاملField Evolved Resistance in Helicoverpa armigera (Lepidoptera: Noctuidae) to Bacillus thuringiensis Toxin Cry1Ac in Pakistan
Helicoverpa armigera (Hübner) is one of the most destructive pests of several field and vegetable crops, with indiscriminate use of insecticides contributing to multiple instances of resistance. In the present study we assessed whether H. armigera had developed resistance to Bt cotton and compared the results with several conventional insecticides. Furthermore, the genetics of resistance was al...
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In 1996, Bt-cotton (cotton expressing a Bacillus thuringiensis toxin gene) expressing the Cry1Ac protein was commercially introduced to control cotton pests. A threat to this first generation of transgenic cotton is the evolution of resistance by the insects. Second-generation Bt-cotton has been developed with either new B. thuringiensis genes or with a combination of cry genes. However, one re...
متن کاملResistance allele frequency to bt cotton in field populations of helicoverpa armigera (Lepidoptera: Noctuidae) in China.
Resistance evolution in target insects to Bacillus thurningiensis (Bt) cotton, Gossypium hirsutum L., is a main threat to Bt cotton technology. An increasing trend of population density of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) has been observed since 2001 in Qiuxian County (Hebei, China), where Bt cotton has been planted dominantly since 1998. This region was selected in 2006 a...
متن کاملCis-mediated down-regulation of a trypsin gene associated with Bt resistance in cotton bollworm
Transgenic plants producing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) are useful for pest control, but their efficacy is reduced when pests evolve resistance. Here we examined the mechanism of resistance to Bt toxin Cry1Ac in the laboratory-selected LF5 strain of the cotton bollworm, Helicoverpa armigera. This strain had 110-fold resistance to Cry1Ac protoxin and 39-f...
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تاریخ انتشار 2017