ORIGINAL PAPER Native isolate of Trichoderma: a biocontrol agent with unique stress tolerance properties N. Mishra 1 • S. S. Khan 1 • S. Krishna Sundari 1 Received: 21 September 2015 / Accepted: 14 May 2016 Ó Springer Science+Business Media Dordrecht 2016 Abstract Species of Trichoderma are widely recognized for their biocontrol abilities, but seldom studied collec- tively, for their plant growth promotion, abiotic stress tol- erance and bioremediation properties. Our study is a concentrated effort to establish the potential of native isolate Trichoderma harzianum KSNM (T103) to tolerate biotic (root pathogens) and abiotic stresses [high salt (100–1000 mM); heavy metal (chromium, nickel and zinc: 1–10 mM); pesticides: malathion (100–600 ppm), carbo- furan (100–600 ppb)], along with its ability to support plant growth. In vitro growth promotion assays with T103 treated Vigna radiata, Vigna mungo and Hordeum vulgare confirmed ‘non-species specific’ growth promotion effects of T103. At lower metal concentration, T103 treatment was found to completely negate the impact of metal stress [60 % increase in radicle length (RL) with no significant decrease in %germination (%G)]. Even at 10 mM metal, T103 inoculation gave 80 % increase in %G and [ 50 % increase in RL. In vitro experiments confirmed high metal reduction capacity (47 %-Cr, 35 %-Ni and 42 %-Zn) of T103 at concentrations as high as 4 mM. At maximum residual concentrations of malathion (440 ppm) and car- bofuran (100 ppb) reported in agricultural soils, T103 maintained 80 and 100 % survivability, respectively. T103 treatment has improved %G and RL in all three hosts challenged with pesticide. Isolate T103 was found to effectively suppress growth of three major root pathogens: Macrophomina phaseolina (65.83 %) followed by Sclerotium rolfsii (19.33 %) and Fusarium oxysporum (19.18 %). In the light of these observations, native T. harzianum (T103) seems to be a competent biocontrol agent for tropical agricultural soils contaminated with residual pesticides and heavy metals. Keywords Biocontrol agent Á Trichoderma Á Salt stress Á Tolerance to heavy metal Á Pesticide tolerance Introduction Mainstream agriculture occupies a prominent place in India, employing over 50 % of Indian population and contributing to 20 % of its GDP. Decreased agriculture productivity and yield due to infestation by soil borne pathogens is one of the major concerns ailing modern day agriculture (Ray et al. 2012). As a result, the agriculture sector invests hugely on pesticides to counter disease and pathogen attack. However, chemical control of soil borne pathogens is turning out to be very expensive, not only in terms of the expenditure it incurs during production, but also in terms of the pollution it causes to environment and loss to soil fertility (Kumari et al. 2008; Aktar et al. 2009). Moreover, the residual pesticides in soil can destroy the beneficial soil microorganisms, and also lead to develop- ment of resistance in target pests, thus disrupting soil microbial diversity. As a consequence, the concept of integrated agricultural management is gaining favor, wherein plant growth promoting microbes (PGPMs) and/or biocontrol agents (BCA) are investigated for offering sus- tainable plant growth and development. Abiotic stress is a significant factor that greatly influ- ences fertility and productivity of agricultural soils. Bioinoculants, with either bio-fertilizer or biocontrol & S. Krishna Sundari krishna.sundari@jiit.ac.in; skrishnasundari@gmail.com 1 Plant and Microbial Biotechnology Group, Department of Biotechnology, Jaypee Institute of Information Technology, A-10, Sector-62, Noida, Uttar Pradesh 201309, India 123 World J Microbiol Biotechnol (2016) 32:130 DOI 10.1007/s11274-016-2086-4