Influence of dieback disease on soil chemistry and bacterial diversity in the rhizosphere of mango plants

Influence of dieback disease on the soil chemistry and the morphological, biochemical, and molecular characteristics of bacteria isolated from the rhi-zosphere of mango plants was studied. The soil samples collected from the rhizosphere of the healthy and dieback-affected mango plants were analyzed for their physicochemical parameters and biochemical characteristics of bacterial isolates. The dieback disease resulted in a significant decrease in pH, water holding capacity, organic matter, total nitrogen content, available phospho-rus content, and available potassium content. The number of bacterial isolates showing oxidase production and lactose and sucrose fermentation was increased while the number of those showing urease and hydrogen sulphide production was decreased in the rhizosphere of diseased plants. The genus Bacillus showed maximum prevalence (97%) among the identified genera of rhizobacteria. Eight bacterial species were found to be absent and eight new species appeared in the rhizosphere of diseased plants. The study would be a significant contribution to the literature regarding the dieback mango disease and its relationship with soil composition and its microflora.