Isolation, identification, and evaluation of the saline-tolerant strain of Trichoderma spp. in the Halogeton arachnoideus rhizosphere

This experiment used the plate separation method to isolate and identify Trichoderma strains with better salt tolerance from the collected saline grassroots soil, and evaluated their salt tolerance by simulating salt stress conditions with different concentrations of NaCl solution. Four strains of Trichoderma were isolated and purified, among which Trichoderma T-B strain had a higher salinity tolerance potential than the other three Trichoderma strains isolated. The morphological and molecular methods of fungal identification confirmed that the isolated Trichoderma T-B strain was T. longibrachiatum. Using different concentrations of NaCl solution to simulate salt stress conditions, there was no significant difference in the growth rate at 100 mmol·L⁻¹ NaCl compared with the control at a culture period of 3～7 days (P > 0.05). However, spore production increased by 9.17%, which was significantly higher than that of the control (P < 0.05). Therefore, T. longibrachiatum was a strong saline-tolerant species, and the results provide a theoretical basis for using Trichoderma to control soil salinization.