Isolation and Identification of Two Potassium Solubilizing Fungi from Arid Soil

Abstract

Five potassium solubilizing microorganisms were isolated from the arid soil of Jodhpur, India. Among them two fungal isolates RCKF7 followed by RCKF5 showed higher dissolution capacity towards feldspar, resulting in the release of more potassium compared to the others. Based on morphological characters and sequencing of ITS1–5.8S–ITS2 region the strains were identified as Fomitopsis meliae RCKF7 and Aspergillus tubingensis RCKF5. On further screening of the more potent strain RCKF7, it showed its ability to grow and solubilize potassium over a wide range of temperature (20 to 38 oC) and pH (5.0 to 10.0). The maximum potassium solubilization index was observed at 28 ºC and pH 6.0. Capability of RCKF7 to solubilize phosphorus also rendered it an additional advantage. Furthermore the application of 500 ppm and 1000 ppm feldspar alone or in combination with RCKF7 resulted in more grain yield in wheat as compared to recommended dose of potassium fertilizer.