The ability of two fungi to dissolve hardly soluble phosphates in solution

Abstract

Low phosphorus availability in soil is one of the major causes that hamper crop yield. The main objectives of this work were to isolate efficient phosphate-solubilising strains from semi-arid soil and to check their efficiency to solubilise different inorganic phosphorus forms (viz., dicalcium phosphate (DCP), tricalcium phosphate and Udaipur rock phosphate) at different temperatures. Initially, 40 strains were isolated from rhizosphere soil of Sesamum indicum grown in semi-arid region of Rajasthan, India, of which 24 isolates showed phosphate-solubilising ability. Further, screening of these isolates for their phosphate solubilisation efficiency in solid media and broth led to the selection of two most competent isolates viz. SI32 and SI39. Both the isolates were effective in solubilising phosphorus at wide range of temperatures with different inorganic insoluble phosphorus sources. Amongst various insoluble phosphate sources tested, DCP was solubilised the most at all the temperatures but the performance was especially good in the range of 25–35°C.