Quantitative analysis of fitness costs associated with the development of resistance to the Bt toxin Cry1Ac in Helicoverpa armigera.

ABSTRACT: Transgenic Bacillus thuringiensis (Bt) crops play an increasing role in pest control, and resistance management is a major issue in large-scale cultivation of Bt crops. The fitness cost of resistance in targeted pests is considered to be one of the main factors delaying resistance when using the refuge strategy. By comparing 10 resistant Helicoverpa armigera (Hubner) strains, showing various resistance levels to Bt toxin (Cry1Ac), to a susceptible strain, we showed an increasing fitness cost corresponding with increasing levels of resistance. The relationship between overall fitness cost C and the resistance ratio Rr could be described by C = 24.47/(1 + exp([1.57 - Log10Rr]/0.2)). This model predicted that the maximum overall fitness cost would be ~24% (± 5.22) in the strains with the high

SUBMITTER: Cao G 

PROVIDER: S-EPMC4088062 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature