Objective  A fungal strain with phosphate-solubilizing and growth promoting properties was isolated from the soil of a Triticum aestivum L. field to investigate its potential as a microbial fertilizer.

  Methods   From the soil at a wheat field, a fungal strain, R3, exhibiting a strong phosphate-solubilizing ability on an inorganic phosphorus medium was isolated. Morphological observation and ITS sequence analysis were performed for taxonomic identification on the isolate. Ability of the isolate in solubilizing Ca₃(PO₄)₂, AlPO₄, and FePO₄ was determined in a liquid culture. A pot experiment was conducted to evaluate the growth-promoting effect of the isolate on T. aestivum seedlings.

  Result   R3 was identified as Penicillium rubens. It produced an average diameter of phosphorus dissolving ring (D) of 27.99 mm, a colony diameter (d) of 19.26 mm, and D/d ratio at 1.45 on the inorganic phosphorus medium. The solubilization on Ca₃(PO₄)₂ and AlPO₄ by R3 peaked on the 4^th day of culture at 328.79 mg·L⁻¹ and 95.99 mg·L⁻¹, respectively, while that on FePO₄ maxed on the 5^th day at 75.39 mg·L⁻¹. The pH of phosphorous solubilization medium by R3 decreased initially and then stable. The pot experiment with wheat seedlings showed the incorporation of R3 in the medium increased the height, root length, fresh weight, and chlorophyll content of the seedlings by 18.23%–35.65%, 27.63%–50.44%, 37.99%–50.94%, and 9.59%–19.57%, respectively, over control.

  Conclusion   The phosphorus-solubilizing R3 demonstrated a significant growth promoting effect on the wheat seedlings in a pot experiment. It could be a potential candidate as a microbial agent for farm fertilization.