Antifungal activity and IAA production by endophytic fungi isolated from Elettaria sp

Abstract

Medicinal plants may become a favourable habitat for associative microorganisms, especially endophytic microbes inhabiting Zingiberaceaen species. Preliminary investigation has revealed an assemblage of endophytic fungi colonizing the healthy rhizome of Elettaria sp. collected from Sibayak Forest, North Sumatra based on molecular evidences. This study investigated the IAA-producing and antifungal activity from Elletaria endophytic fungi identified as Curvularia lunata, Pholiota multicingulata, Trichoderma atroviride, T. harzianum and Schizophyllum commune. Quantification of IAA was based on colorimetry method using Salkowsky reagent which produced pinkish to reddish solution indicating the presence of IAA. Antagonistic test was based on dual culture assay measured in colony growth inhibition (%). Statistical test to signify the differences were analysed using one-way ANOVA. C. lunata produced the highest IAA concentration of 45.17 µg.mL−1 followed by S. commune, and T. atroviride with concentration of 11.7 and 5.27 µg.mL−1, respectively. The strongest antagonistic activities were displayed by T. harzianum against both G. boninense (CGI>75%) and R. lignosus (CGI>50%). In addition, the strongest endophytic fungus against F. oxysporum was P. multicingulata (CGI>70%). Further investigations are being conducted to elaborate other plant growth promotion properties and even characterization of bioactive metabolites produced by Elettaria endophytic fungi.