Isolation of Endophytic Fungi From Tridax Procumbens Grown in Contaminated Sites and Assessment of Their Heavy Metal Tolerance

Seven strains of endophytic fungi were isolated from the leaves of Tridax procumbens and were first screened individually for tolerance to heavy metals like Zn, Pb, Cu, Mg, and Cr from 5 ppm to 50 ppm on Potato dextrose agar medium. They were further tested for resistance at 75, 100, 200, 400, and 600 ppm of heavy metals. The fungal isolate on the PDA medium without any heavy metal was used as a control for growth comparison. It was observed that with increasing concentration of heavy metal from 5 to 600 ppm there was a decrease in the number of fungal isolates. Few of the fungal isolates were able to tolerate heavy metals up to 600 ppm. The screening test revealed heterogeneity in the heavy metal tolerance of the isolates.