Objective  Effect of introducing various arbuscular mycorrhizal fungi (AMF) in soil on the growth and salt-tolerance of tomato plants was studied.

  Method  After a preliminary screening, two potentially applicable AMF, Moses (F.m) and rhizosphere (R.i), were added to potting soils with salt concentrations of 0 (CK) and 100 mmol·L⁻¹ for a tomato plant cultivation experimentation. Physiological and photosynthetic properties of the plants were monitored.

  Result  The AMF-treatments increased superoxide dismutase (SOD) activity by 47.4%, peroxidase (POD) activity by 32.9%, catalase (CAT) activity by 35.7%, malondialdehyde (MDA) content by 61.8%, and proline (PRO) content by 6% of the tomato plants under the imposed salt stress. Meanwhile, the mycorrhizal infection rate and photosynthetic intensity decreased by 27.8% and 54.6%, respectively. The inoculation effectively enhanced the resistance of the host plants to high salinity. The proline content of the tomato plants grown on the F.m-inoculated soil declined 60.7%, which was 2.2 times of that on R.i-inoculated counterpart. The net photosynthetic rate (P_n) and stomatal conductance (G_s) of the tomato plants on the F.m-inoculated soil increased by 49.1% and 35.4%, respectively, which were 1.4 times of R.i-inoculation. In addition, the damage to the key photosynthesis enzymes was reduced, as the maximum increase rate of RuBP carboxylase in the tomato plants rose to 31.2% under the F.m-treatment and 1.1 times of which under R.i.

  Conclusion  The introduction of AMF in soil could delay the adverse effect of high salinity on the physiological activities, improve the photosynthetic carbon assimilation and salt tolerance, and promote the growth of tomato plants. Of the two candidates, F.m was shown to significantly superior to R.i for the application.