Biodiversity and Plant Growth Promoting Potential of Bacteria from Soybean Rhizosphere of Saline Soil

Abstract

PGPR are root-associated bacteria that form symbiotic relationships with many plants. These are the Bacteria that colonize plant roots and promote plant growth are referred to as plant growth-promoting rhizobacteria (PGPR). PGPR are highly diverse and are important in plant growth promotion and increase in yield of crops. Almost all of the PGPR bacteria produce phytohormones, some fixes atmospheric nitrogen, some solublizes the phosphates and some resist phytopathogens by production of siderophores. An understanding of microbial diversity is important in agricultural contest, it is important and useful to know soil quality in terms of PGPR bacteria which is helpful for taking measures for soil management and increased plant productivity. It is also important to understand the relationship of soil and plants with the diversity of associated bacteria for their better exploitation. Therefore, it is important to know the soil micro flora and their diversity. Most of the rhizospheric bacterial diversity from normal soil have been studied and organisms explored for their use as bioinoculents. However, saline soil rhizospheric microfloras remain unexplored. By considering this, in the present study fifty two bacterial isolates including PGPR have been isolated from saline soil of Kolhapur district of southern Maharashtra, India. Isolates were identified up to genus and species level. Few isolates were studied their nitrogen fixing and phosphate solublizing activity. Present study showed that amongst nitrogen fixing bacteria Azotobacter chroococcum found to be most dominant and Bacillus megaterium was found to be most dominant phosphate solublizer. Study indicated the importance of these organism as bioinoculents for saline soil and can be explored for biofertilizer production.