Influence of management practices on the diversity of pseudomonads in rhizosphere soil of wheat cropping system

The composition and diversity of the bacterial communities associated with plant root is influenced by various biotic and abiotic factors. In this study, effect of soil management practices, conventional (pf) and raised bed (rb), are compared for bacterial diversity in rhizosphere of wheat (Triticum aestivum) var. UP2338, taking pseudomonads as a biomarker. Microbial diversity was assessed employing culturable and unculturable approaches. Amplified rDNA restriction analysis showed that soil management practices and site of sampling (rhizosphere-RS and rhizoplane-RP) affected the composition of microbial communities. Sample from conventional management showed a higher Pseudomonas diversity (H′ = 3.7) than that from raised bed (H′ = 2.78). However, total bacterial diversity (SSCP data) was more complex in rb than pf management. Dominant members of both pf and rb were γ-proteobacteria as Pseudomonas was dominant over other forms, while Bacillus species were only present as low numbers in rb.