ABSTRACT Understanding the genetic basis of pest resistance to Bacillus thuringiensis (Bt) (Berliner) (Bacillales: Bacillaceae) toxins is important for optimizing integrated pest management (IPM). In this study, we characterized a strain (Cry1S1000) of Plutella xylostell a (Linnaeus) (Lepidoptera: Plutellidae) highly resistant to Bt using genetic crosses and dose‐response bioassays. This strain exhibited >13,333‐fold resistance to Cry1Ac toxin, which was conferred by a single autosomal locus and inherited in a completely recessive manner. Cross‐resistance profiling revealed high‐level resistance to Cry1Aa (>115‐fold) and Cry1Ab (491‐fold), but only minimal resistance to Cry1C (5‐fold). These findings elucidate the evolution and mechanisms of Bt resistance in P. xylostella and provide a foundation for developing targeted resistance management tactics to sustain Bt efficacy.
Xiao et al. (Sun,) studied this question.