Molecular characterization of bacterial and fungal endophytes associated with Vanda testacea, an orchid of Kodagu forest (Western Ghats), India

Abstract

Western Ghats is considered as one of the most important biogeographic zones of India and also major tropical evergreen-forested region that possesses enormous biodiversity. Challenging biodiversity due to decreasing forests and thereby related habitat loss triggered us to give a hand on conservation of microbial diversity in such regions. Vanda testacea a vulnerable epiphytic orchid from Kodagu, is in the heart of Western Ghats which was used for endophyte isolation and characterization in the current study. From leaves of V. testacea fungal and bacterial strains were isolated. Further, by using molecular methods, the genomic DNA of isolated strains was extracted. The ITS region from fungi and 16S rDNA from bacteria were amplified by PCR, and then sequenced. Nucleotide sequences were compared with the known sequences available in NCBI database. Sequence similarity matrix were prepared with closely related species and phylogenetic tree was also generated for homology comparison. Identity of isolated strains was established as two different endophytic fungi, Cladosporium perangustum and Pestalotiopsis maculans and two different strains of Bacillus pumilus upto its genotypic level from the epiphytic orchid, V. testacea. Studies related to endophyte from orchids and identifying them by comparing its sequence are meagre. However, further rigorous trials are necessary to identify diversified endophytes from the epiphytic vulnerable orchid plant habitat and so as to make strategies for biodiversity conservation of Western Ghats, one of the hottest biodiversity hotspots of the World.