Interspecies diversity of Bacillus thuringiensis isolates native from North Western Indian Himalayas

Abstract

Aim: Bacillus thuringiensis (Bt) is a ubiquitous pathogenic bacterium exploited worldwide in successful insect pest management programs. The present study aimed at resolving the diversity status and genetic structure of Bt isolates collected from unique and native ecological niche, north-western Indian Himalayas. Methodology: Forty five Bacillus thuringiensis (Bt) isolates native to Uttarakhand, India were analyzed for their genetic diversity using Arbitrary Primed-Polymerase Chain Reaction (AP-PCR) patterns (ERIC1, ERIC2, BOX and GTG) and gyrase B (gyrB) sequences. Results: Amongst the AP-PCR patterns, ERIC and BOX primers clearly indicated the genetic inconsistency of Bt by differentiating low and high hill isolates with unique banding pattern. A dendrogram generated showed fastidious clustering with coexistence of attitudinally related strains, indicating the genetic relatedness with respect to geographical proximity. The gyrB (285 bp) dependent phylogeny of seven selected isolates revealed their genetic proximity with different serovars. Interpretation: The present study demonstrates that ERIC and BOX-PCR can be used in establishment of geographical variation and gryB in phylogenetic relatedness with serovars. Genetic relatedness between Bt isolates was found to be a function of geographical proximity.