College of Agriculture, Acharya N G Ranga Agricultural University, Rajendranagar, Hyderabad - 500 030, Andhra Pradesh, India.
*Part of MSc thesis submitted by first author to the Acharya N G Ranga Agricultural University, Rajendranagar, Hyderabad - 500 030, Andhra Pradesh, India.
Field populations of diamondback moth (DBM) were sampled from cabbage and cauliflower agro-ecosystems to detect the presence of resistant alleles conferring resistance to Cry1Ac, cartap hydrochloride and novaluron using F2 screen method. From 303 founder females maintained, only 27 isofemales produced progeny or F2 larvae that were screened to detect alleles conferring resistance against Cry1Ac, cartap hydrochloride and novaluron at their respective discriminative doses. Eleven F2 larvae derived from five isofemale lines survived in the F2 generation after bioassay and on re-evaluation in F3 generation proved as false positives and confirmed the absence of resistant alleles. The estimated frequency of resistant alleles using Bayesian inference was 8.6x10−3 with associated variance of 6.93 x 10−5 at 95% Credibility Intervals of 2.1x10−4 to 3.3x10−2 (these are the lower and upper limit for the expected frequency of resistance alleles) with an experiment-wise detection probability of 52 per cent.
Diamondback moth, Bacillus thuringiensis, isofemales, detection probability, Bayesian inference
