Abstract:In order to explore the effects of inoculation of arbuscular mycorrhiza (AM) fungi on the colonization characteristics and physiological indexes of Mentha spicata and Dianthus plumarius under different salt stress levels, we used the method of pot experiment in this study to divide M. spicata and D. plumarius into inoculation treatment and control treatment, and applied different concentrations (0, 50, 100, 150, 200 mmol/L) of NaCl stress. After the end of the stress, we measured the colonization characteristics and physiological indicators of the two plants. The results showed that: (1) with the increase of salt concentration, the colonization rate, colonization intensity, arbuscular abundance and vesicle abundance of M. spicata and D. plumarius continued to decrease, and the various colonization indexes of D. plumarius are generally higher than that of M. spicata. (2) Inoculation of AM fungi increased the total chlorophyll content, soluble sugar and soluble protein contents of M. spicata and D. plumarius in each salt concentration, while significantly reducing the proline content of the two under different salt concentrations. (3) Inoculation with AM fungi increased the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) in M. spicata and D. plumarius to varying degrees, and reduced the malondialdehyde content of M. spicata and D. plumarius under different salt concentration. The study found that inoculation with AM fungi can improve the osmotic adjustment ability and antioxidant enzyme system activity of M. spicata and D. plumarius in different degrees under salt stress, enhance the salt tolerance of plants, and make plants grow better under salt stress conditions.