Assessment of rhizobacterial diversity of Triticum aestivum and Eleusine coracana from Northern region of India.

摘要

In addition to plant and soil type, cultivation practices greatly influence the rhizospheric microbial community. In this study, the influence of plant type was studied in mandua (Eleusine coracana), an organically grown crop for nearly a century in the Central Himalayan region and, wheat (Triticum aestivum), cultivated employing chemical nutrient inputs in the IndoGangetic region. Species variation was determined based on classical biochemical and physiological tests. Numerical analysis of these characteristics showed that 36% isolates from mandua were 100% similar whereas 18% strains from wheat showed 100% similarity. The extent of similarity between the isolates belonging to these two crops was limited to approximately 20%. Based on numerical analysis of phenotypic characters, the Shannon diversity index (H') was 0.64. However, the value of H' based on phylogenetic analysis was 0.77. Functional characterization based on plant growth-promoting properties clearly showed greater diversity in wheat rhizosphere than in mandua. Molecular characterization by BOX-PCR and ARDRA substantiated the phenotypic data. Isolates from any one crop were placed distinctly in a separate cluster. Shannon diversity indices for wheat and mandua rhizospheric isolates based on genotypic fingerprinting were 0.6 and 0.2 respectively, which was in agreement with the phylogenetic analysis data. Sequencing data showed predominance of genera, Bacillus and Pseudomonas.