Antibacterial activity and preliminary phytochemical screening of the extracts of the bark of Saraca asoca (Roxb.) Wild.(Caesalpiniaceae)

Abstract :

An appropriate formulation of bacterial inoculum is required to enhance the productivity of plants in field. Sawdust, sugarcane-bagasse and charcoal were used as solid carriers to enhance the shelf-life of bioinoculants.Plant growth promoting rhizobacteria (PGPR) screened from tomato rhizosphere were characterised and identified on the basis of carbon source utilization by comparing with standard bacterial cultures and UPGMA cluster analysis using MVSP software version 3.2. Pseudomonas sp. LEP17, Azotobacter sp. LEP21 and Bacillus sp. LEP25 showed synergistic effect with each other. Three bacterial consortiashowed the maximum viability on sawdust followed by charcoal and sugarcane-bagasse at 360th day of inoculation. Seed germination and seedling emergence got increased with treatment of bacterial isolates individually as well as its consortia. The above bioformulation enhanced the growth of Lycopersicon esculentum in field trials. The tripartite consortium of Pseudomonas sp. LEP17, Azotobacter sp. LEP21 and Bacillus sp. LEP25 resulted in better growth followed by twin bacterial consortium and individual isolates