Vol. 12, Special Issue 9 (2023)

Author(s):
Thilagarajan R, N Balakrishnan, G Rajadurai, Sheela Venugopal, R Raghu and E Kokiladevi

Abstract:
Bacillus thuringiensis (Bt) is a widely distributed Gram-positive bacterium known for its ability to produce insecticidal toxins with high specificity for certain insect pests. In this study, 15 indigenous Bt isolates were characterized and screened for lepidopteran toxic insecticidal genes through PCR. The colour, surface, shape, elevation and margin of the isolates were studied. Diversified crystal shapes were observed among the isolates tested. PCR analysis confirmed the presence of cry1, cry2 and vip3A genes in the isolates, either individually or in combination, while none of the isolates possessed cry9 gene.