In Vitro Antimycotic and Biosynthetic Potential of Fungal Endophytes Associated with Schima Wallichii

Abstract

Endophytic microorganisms reside inside healthy tissues of plant without causing any apparent disease symptoms and have profound effect on plant fitness by conferring protection to plants against biotic and abiotic stress. The aim of the study was to evaluate the antifungal potential of fungal endophytes associated with Schima wallichii and their potential to produce bioactive compounds according to detection of the conserved ketosynthase domain (KS) of polyketide synthase (PKS) gene. In total 126 endophytic fungal isolates representing 15 morphologically different genera were recovered. Sordariomycetes (50.79 %) was the most dominant class followed by Dothideomycetes (42.06 %) and Eurotiomycetes (7.14 %). Colonization frequency was greater in stem (75.38 %) followed by leaf (61.53 %) and bark (56.92 %). The most frequent colonizing genus were Alternaria, Phomopsis, Colletotrichum, Chaetomium and Penicillium. Fermentation extracts of each strain was screened for their biocontrol ability against Macrophomina phaseolina, Aspergillus flavus and seven phytopathogens of the genus Fusarium. Twelve potential antagonistic strains were identified by amplification of ITS rDNA region. Isolate number EF-18 and EF 49, identified as Penicillium simplicissimum (KJ826510) and Talaromyces verruculosus (KJ826513) respectively showed highest degree of antagonisms against tested pathogens. Further, three pairs of primers (LC1/2c, LC3/5c, KS3/4c) were used to amplify KS domain of NR-type PKS, PR-type PKS and HR-type to prove the biosynthetic potential of the isolates. Nine isolates were found to contain at least two types of KS domain of which seven isolates belong to Eurotiomycetes. Our findings conclude that S. wallichii harbors fungal community with high bioactive potential which further can be explored for the development of biocontrol agents for sustainable development.