Isolation, Characterization and Plant Growth Promotion abilities of PSB Isolates from Millet Grown Fields

Author: S. Vigi and S. Antony

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Abstract

Despite the various forms of phosphorus present in soils, both organic and inorganic, they commonly serve as primary growth-limiting factors for plants. Although soil contains organic compounds with total phosphorus, the majority remains dormant and inaccessible to plants. Enhancing phosphorus solubilization through bacteria and inoculants can significantly boost crop production and the absorption of phosphorus by plants. The phosphate-solubilizing bacteria (PSB) released a substantial amount of phosphorous, with productive strains in rhizosphere soils showing particularly high levels of phosphorus release. To eliminate duplication among isolates from the same sample, three strains were carefully chosen based on distinct colony morphological traits and ability of phosphate solubilization. Morphological and biochemical tests, coupled with growth promotion studies, were conducted on these isolates for identification. Subsequently, these selected isolates were made available for further molecular research, revealing their classification as members of Burkholderia sp. through 16s rRNA sequence analysis. Roll towel assay was used for assessing the seedling vigour index of Bajra after seed priming with the PSB isolates. Hence, phosphate solubilising bacteria isolated from millet fields could be used as plant growth promoting bioagents.

Keywords

PSB, pikovyskayas medium, phosphate solubilization, millets, organic acids

Conclusion

The current findings suggest that phosphate solubilising bacterial isolates had better efficiency in plant growth promotion by production of phytohormones and seedling vigour index assay. It is revealed that Burkholderia cepacia PSB 13 could be a promising phosphate solubilizing bioagent with plant growth promotion activity. The increase in plant growth promotion might be due to the higher production of IAA and GA. Phosphate solubilizing isolates with plant growth promoting potential to be applied as biofertilizer for sustainable agriculture has been identified in this study. They can be exploited for commercial production after further evaluations. It is advisable to have a consortium made with different isolates obtained from the same crop plant than the individual isolates for the use in plant health management as many with varying PGP traits act together and perform in a better way. The biopriming treatment enhanced the plant growth through various direct mechanisms such as production of IAA, GA, ammonia, HCN, siderophore, ACC deaminase activity, nitrogen fixation and phosphorus solubilization. Moreover, it is concluded that, PSB isolates offer promising opportunities for improving soil fertility, promoting plant growth, and enhancing environmental sustainability in agriculture.

References

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How to cite this article

S. Vigi and S. Antony (2023). Isolation, Characterization and Plant Growth Promotion abilities of PSB Isolates from Millet Grown Fields. Biological Forum – An International Journal, 15(6): 810-818.