Abstract
Endophytic fungal strains isolated from indigenous Nicotiana plants naturally growing in dry and hot regions of north-western Australia were characterised based on their tolerance to salinity and temperature. Sixty-eight fungal isolates were tested on eight levels (0.5 M, 1.0 M, 1.5 M, 2.0 M, 2.5 M, 3.0 M, 3.5 M and 4.0 M) of five different of salts solutions NaCl, KCl, MgCl2, CaCl2 and MgSO4 and at various temperatures (25–50 °C). The salt adaptation test indicated that the fungal strains namely Aspergillus niger (E-202), A. ochraceous-A (E-134), Aurantiporus sp. (E-135), Cladosporium halotolerance (E-128), Pleurostomophora richardsiae (E-13) and Trichoderma sp. (E-185.1) were tolerant to higher concentrations of various salts. The most growth-limiting salt turned out to be MgCl2 followed by the chaotrope CaCl2. Responses to temperature tolerance revealed that most fungi tested could grow at 30 °C. About 50% all the fungi did not show any growth when the temperature was raised above 30 °C. When the temperature was raised up to 50 °C all the fungi failed to grow but the fungus Rasamsonia piperina (E-172). Endophyte strains identified could be promising candidates for future research in investigating the fungus–plant interactions and their roles in plant adaptation to inhospitable environments.
Disclosure statement
No potential conflict of interest was reported by the authors.
Funding
The first author was supported through “Research Training Program” scholarship formerly known as “International Postgraduate Research Scholarship (IPRS)” by Murdoch University.