Journal of Applied Sciences Research, 4(6): 592-598, (2008)
Effect of Phosphate Solubilizing Fungi on Growth and Nutrient Uptake of Soybean (Glycine max L.) plants
Iman M. El-Azouni
Botany Department, Faculty of Science, Zagazig University, Zagazig, Egypt.

Abstract: Aspergillus niger and Penicillium italicum were isolated from the soil and rhizosphere of different plants. They were tested for their efficacy to solubilize tri-calcium-phosphate (TCP) in vitro as well as their effect in vivo to promote the growth of soybean (Glycine max L.) plants grown in soil amended with TCP. The results showed high solubilizing index in agar plates. Also, they effectively solubilized TCP in Pikovskaya's liquid medium (PVK) and released considerable amounts of P into medium. The efficacy of Penicillium italicum to solubilize and release the inorganic P was 275 μg P ml-1 whereas Aspergillus niger showed better efficiency and produced 490 μg P ml-1 after seven days of incubation. Drop in pH during growth was more prominent in absence of TCA in liquid medium. This indicated that absence of soluble P in media induces the acid production. The addition of TCP to the broth media produced an increment in fungal biomass. Pot experiment showed that the dual inoculation of phosphate-solubilizing fungi (A. niger and P. italicum) significantly increased dry matter and yield of soybean plants compared to the control soil. Significant increment in percentage of protein and oil was also recorded. There was an increase in the percentage of N and P content of the plant. It was significantly resulted with N levels of soybean plants but this increase was non-significant with the percentage of total phosphorus, under the experimental conditions. Soil analysis showed that the available P, organic carbon levels were significantly increased when compared to the initial soil. The pH was also lowered compared to the initial pH of the soil.

Bacteria and Soil Fertility

Mycorrhizal Fungi