Identification of phosphate solubilizing fungi under Scaphium macropadum stands in Gunung Leuser National Park, North Sumatra

Abstract

Scaphium macropadum is a wild tree species producing important timber and medicinal fruits. As a result of overexploitation, this species has decreased its population in the wild although categorized as least concern based on the IUCN red list of threatened species. Phosphate solubilizing fungi (PSF) are a group of soil microorganisms that can increase the availability and uptake of phosphorus (P) by plants. This study aims to isolate the phosphate solubilizing fungi from the soil under Scaphium macropadum stands following its morphological identification of species. Soil sampling was carried out randomly, with a depth of 0-20 cm under 12 stands of Scaphium macropadum in Gunung Leuser National Park, North Sumatra. Isolation of PSF was carried out using Pikovskaya medium with tricalcium phosphate (Ca3(PO4)2) as a source of inorganic P then the solubilization activity was expressed in the solubilization index (SI). The isolates obtained were identified morphologically to the genus level. The results obtained 15 isolates of PSF with SI ranging from 0.96 to 1.16. Based on the morphological identification, all isolates were identified as members of Aspergillus.