author(s)
Hafiz Imran Hussain, Zain ul Abdin, Muhammad Zeeshan, Asad Bashir, Husnain Yaseen, Zaheer Abbas and Muhammad Sibtain Khan

abstract
Although the country has adopted transgenic cotton (Bollguard-I) over the area of 86%. Monitoring the early phases of pest resistance to (BT) crops is crucial, but it has been extremely difficult because bioassays usually cannot detect heterozygotes harbouring one allele for resistance. The pink bollworm, Pectinophora gossypiella (Lepidoptera: Gelechiidae) is one of the most serious lepidopteron pests of cotton in the world. Cotton production in Pakistan has remained stagnant due to many reasons. Transgenic crops producing toxins from the bacterium Bacillus thuringiensis (BT) kill insect pests and can reduce reliance on insecticide sprays. Although (BT) cotton (Gossypium hirsutum L.) cover a large scale cultivated area in Pakistan but their success could be cut short by evolution of pest resistance. Monitoring of resistance to (BT) cotton with DNA-based screening was performed for the detection of single resistance alleles in heterozygotes. Sampling of cotton bolls were carried out from cotton field grown in different locations of district Faisalabad. For the detection of resistance gene, a simple Polymerase chain reaction (PCR) was performed with gene specific primers that specifically amplify cadherin gene linked with resistance to (Bt) cotton in pink bollworm, P. gossypiella later on the quality of the amplified genes (PCR product) were analysed on 1% Agarose gel electrophoresis. This preliminary study would be helpful in devising effective resistance management strategies for the control of PBW.