Vol. 9, Issue 2, Part A (2025)

Bacillus thuringiensis (Bt) is a widely recognized biocontrol agent known for its insecticidal activity and production of bioactive compounds, including Cry toxins and chitinases. The genetic diversity of Bt plays a critical role in its adaptability, efficacy, and biocontrol potential. This study explores the genetic diversity of 33 Bt isolates collected from diverse agroclimatic zones in India, along with three reference strains. Amplified Ribosomal DNA Restriction Analysis (ARDRA) and 16S rRNA gene sequencing were employed to assess genetic variability and phylogenetic relationships among the isolates. ARDRA, using four restriction enzymes (AluI, HaeIII, HinfIII, and TaqI), generated unique banding patterns, facilitating effective strain differentiation. The 16S rRNA gene sequences were analyzed to construct phylogenetic relationships using the Maximum Likelihood method. The results revealed significant genetic diversity among the isolates, with distinct clustering patterns observed in the dendrogram. The findings highlighted the robustness of ARDRA as a reliable molecular tool for studying bacterial diversity and reinforce the potential of Bt isolates as effective candidates for sustainable pest and disease management in agriculture. This study enhances the understanding of Bt isolates by combining ARDRA for preliminary microbial typing and genetic polymorphism detection with 16S rRNA sequencing for deeper evolutionary insights.