ORIGINAL PAPER Isolation, characterization, and bioactivity of endophytic fungi of Tylophora indica Susheel Kumar • Nutan Kaushik • Ruangelie Edrada-Ebel • Rainer Ebel • Peter Proksch Received: 26 April 2010 / Accepted: 21 June 2010 / Published online: 3 July 2010 Ó Springer Science+Business Media B.V. 2010 Abstract Dothediomycetes sp., Alternaria tenuissima, Thielavia subthermophila, Alternaria sp., Nigrospora ory- zae, Colletotrichum truncatum, and Chaetomium sp. were isolated as endophytic fungi from leaves and stems of the medicinal plant, Tylophora indica, based on rDNA sequencing of ITS region and microscopic examination. Alternaria tenuissima, Colletotrichum truncatum, and Alternaria sp. were found to be active against both Scle- rotinia sclerotiorum and Fusarium oxysporum. Chaetomi- um sp. showed very mild activity against Sclerotinia sclerotiorum and Fusarium oxysporum. Whereas Dothide- omycete sp. and Thielavia subthermophila showed high activity against Sclerotinia sclerotiorum. Methanol extract of Dothediomycetes sp. showed 66.5% growth inhibition (GI) at 500 lg/ml. Keywords Endophytic fungi  Tylophora indica  Sclerotinina  Bioassay Introduction Endophytes are the micro-organisms that colonize the interior of the plant parts, without having any negative effect on the host (Arnold et al. 2003), rather helping the plant by imparting resistance to host plant against biotic (Breen 1994; Schulz et al. 1999; Dingle and McGee 2003) and abiotic stresses (Siegel et al. 1990; West 1994). Every plant species examined till date harbors endophytic fungi (Strobel 2006). In addition to providing wide range of activities against plant pathogens and herbivores, endo- phytic fungi are known to produce bio-molecules of phar- maceutical and agricultural importance. Many of the bioactive metabolite from endophytic fungi act as plant defence activator and have been useful in novel drug dis- covery (Owen and Hundley 2004). Muscador albus, an endophytic fungus of rainforest plant, is known to produce volatile organic compound responsible for fumigant activity against stored grain pests (Strobel 2006; Strobel et al. 2001). Several antimicrobial metabolites, such as colletotric acid (Zou et al. 2000), griseofulvin (Park et al. 2005), are reported from endophytic fungi. Nematicidal activity is also reported from the culture filtrate of Fusarium oxysporum, an endophytic fungus of tomato (Hallmann and Sikora 1996). Metabolites of endophytic fungi responsible for pesticidal activity have been reviewed by Kumar et al. (2008). Tylophora indica, a medicinal plant of Asian origin, is known to host several metabolites having insecticidal property (Kathuria and Kaushik 2006) and medicinal property (Reddy 2009). The plant is not reported to be attacked by many plant pathogens and pests, so endophytic micro-biota of the plant can be of great help as its presence probably protects the plant. Present paper describes the diversity of endophytic fungi isolated from Tylophora indica and their bioactivity against plant pathogenic fungi. S. Kumar TERI University, 10 Institutional Area, Vasant Kunj, New Delhi 110070, India N. Kaushik (&) The Energy and Resources Institute (TERI), India Habitat Centre, Lodhi Road, New Delhi 110003, India e-mail: kaushikn@teri.res.in R. Edrada-Ebel  R. Ebel  P. Proksch Institut fu ¨r Pharmazeutische Biologie und Biotechnologie, Heinrich-Heine-Universita ¨t, 40225 Du ¨sseldorf, Germany Present Address: R. Ebel Department of Chemistry, University of Aberdeen, Meston Building, Meston Walk, Old Aberdeen, Scotland AB24 3UE, UK 123 World J Microbiol Biotechnol (2011) 27:571–577 DOI 10.1007/s11274-010-0492-6