Endophytic fungal assemblage in Achyranthes aspera Linn. revealed by internal transcribed spacer region of nuclear ribosomal RNA genes

Abstract

Only scanty reports are available on endophytic fungal associations in Achyranthes aspera Linn. Hence in this study a total of 504 isolates belonging to ten different species of fungi were isolated from asymptomatic, surface sterilised segments of leaf, stem and root of A. aspera collected from different locations of Kerala, India. Among the isolates ascomycetes were most prevalent. Colonisation rate of fungal endophytes was high in leaf tissue (95%) followed by stem (77.75%) and root segments (33.33%). The most frequent and dominant coloniser of the host plant were Colletotrichum sp., which was isolated from all locations. Scanning electron microscopy demonstrated the presence of hyphae in the intra and intercellular spaces of the plant tissue. Morphological and phylogenetic analyses using internal transcribed spacer (ITS) sequences of nuclear rRNA genes showed that the fungi recovered belonged to the lineages of Sordariomycetes, Dothideomycetes, Eurotiomycetes and Tremellomycetes. A maximum likelihood tree revealed the relationship between the obtained sequence data and the closest sequences retrieved from the GenBank.