Studies on correlations between soil chemistry and bacterial population in rhizosphere of Bt and non-Bt cotton and characterization of rhizobacteria

Abstract

The present study was planned to explore the relationship between soil chemistry with bacterial population of Bt and non-Bt cotton and their phenotypic and molecular characteristics. The pre-plant soil and rhizospheres of Bt and non-Bt cotton were collected and analyzed for some soil parameters and bacterial population. The bacterial isolates were analyzed for their morphological, biochemical, and molecular characteristics. Bacterial population showed a significant (p < 0.05) positive correlation with clay content, electrical conductivity, organic matter, total nitrogen, and available phosphorus and potassium negative with correlation with pH. Bt cotton showed a non-significant effect on the soil parameters, significant decrease in bacterial population, change in the morphological and biochemical characteristics of rhizobacteria and replacement of four bacterial species with five new ones suggests the potential effect of Bt cotton on its rhizoflora. The rhizosphere of non-Bt cotton cultivated in the fertile agriculture field was found to be the best for bacterial growth.

Keywords

• bt-cotton
• rhizobacteria
• rhizosphere
• phylogenetic analysis
• 16s ribosomal rna gene
• soil parameters