Bacillus thuringiensis (Bt) crystal (Cry) proteins have specific insecticidal activity against insect 

pests and thus, extensively used in biological control applications worldwide. In this study, cry 

gene frequency and profile of local Bt isolates, obtained from soil samples from Adana Province of 

Turkey, were studied. Cry gene spectrum of isolates from different ecological sources may 

significantly vary. A total of 120 isolates obtained from 80 different locations were used to 

investigate cry gene contents. Altitude of soil sampling sites varied between the sea level and 1582 m. Total DNA of bacterial samples were subjected to PCR reactions using cry1Ab/Ac, cry1Aa/Ad, cry1Ac, cry1C, cry1B, cry1Ad, cry1D, cry2, cry3-7-8, cry4A, cry5, cry6, cry9A, cry9C and cry11A/B primer pairs. Samples were then electrophoresed on agarose gel to determine the cry gene profiles. Results revealed that 88 of the isolates yielded the expected-size PCR band. Among them, 63 isolates produced more than one PCR band. With the use of cry1C, cry1Ac, cry1Ad, cry1Ab/Ac, cry1Aa/Ad, cry1D, cry1B, cry2 and cry5 primers, 18, 2, 5, 42, 34, 2, 5, 28 and 26 isolates produced relevant PCR bands, respectively. Similarly, with the primers cry4A, cry3-7-8 and cry11A/B, 1, 4 and 7 isolates also yielded the relevant sized PCR bands. It was clear that the cry gene spectrum of isolates were quite different from each other. Frequency of cry1C, cry1Ad, cry1Ac, cry1Ab/Ac, cry1Aa/Ad, cry1D, cry1B, cry2, cry3-7-8, cry4A,cry5, cry9A, cry9C and 

cry11A/B were respectively estimated as 20.68, 5.75, 2.27, 47.72, 37.50, 2.27, 5.68, 31.82, 4.55, 1.14, 28.41, 4.55, 27.27 and 7.95% 

 

Keywords: Bacillus thuringiensis, cry gene, cry gene frequency, isolate