Identification and performance of stress-tolerant phosphate-solubilizing bacterial isolates on Tagetes minuta grown in sodic soil

摘要

Tagetes minuta is moderately adapted to a wide range of climate and due to its tolerance to larger salt, pH and exchangeable sodium percentage (ESP) in soil it is considered to be a potential crop for salt-affected soil. Its tolerance to adverse condition and association with halophilic microbes can combine to play a greater role in crop production and improvement in soil health. After screening, the potential phosphate-solubilizing bacteria (PSB) RS-1, RS-2 and RS-3 were isolated from sodic soils and tested in pot experiment using a naturally occurring sodic soil of pH 9.3 and an ESP of about 45. Under optimum conditions in the laboratory, these bacteria showed phosphorus solubilization potential in liquid medium containing tricalcium phosphate (TCP). Inoculation of PSB significantly increased plant growth in terms of height, number of branches, dry matter accumulation and nutrient uptake. Significant changes were also found in content and quality of essential oil. It was observed that PSB also improved the physical, chemical and biological properties of soil. The bacterial strains tested in this study have the potential for use as a biofertilizer in sustaining the growth of Tagetes minuta in salt stress soil and mitigating soil stress problems.