Isolation and characterization of phosphate solubilizing bacteria in Erbil soil and study their effects on Cicer arietinum plant growth and phosphorus uptake

Abstract

Plants require phosphorus from soil as phosphate anion. It is the least mobile element in plant and soil contrary to other macronutrients. Some soil microorganisms play an important role in plant nutrition through increase in phosphate uptake by plants and used as biofertilizers for agricultural crops. A study was conducted to isolate phosphate solubilizing bacteria (PSB) from Erbil soil. Twenty isolates of PSB were isolated from thirty rhizospheric soil samples of Erbil governorate. The isolates belonged to Bacillus megaterium and Pseudomonas putida. For pot experiment, two efficient PSB isolates selected from the colonies based on their ability to form clear halo zone on Pikovskaya‘s agar medium, and they were also able to solubilize tricalcium phosphate in broth culture and released high amount of phosphorus. Pot experiment showed that both bacterial species remarkably enhanced plant (Cicer arietinum) height, root length, root and shoot dry weight, phosphorus uptake and available P- content of soil compared to the control. Based on the results, it could be concluded that PSB isolates (Bacillus megaterium and Pseudomonas putida) possess great potential to be developed as biofertilizer to enhance soil fertility and plant growth.