Abstract: This research studied the effects of different arbuscular mycorrhiza (AM) fungi on the growth of Salvia miltiorrhiza and the activities of soil enzymes, with the aim of identifying new methodology for improving soil properties using S. miltiorrhiza. Plantlets of S. miltiorrhiza were tissue cultured with a single strain (8 strains were tested) or mixed strains of symbiotic AM fungi (35 combinations were tested) to determine the yield of medicinal parts of S. miltiorrhiza after co-culture with AM fungi. In addition, rhizospheric soil of the cultured S. miltiorrhiza plants was collected to measure the activities of invertase, phosphatase and urease enzymes in the soil. It was found that the tested AM fungi were able to successfully colonize the S. miltiorrhiza plantlets to form mycorrhizal fungal associations, but the mycorrhizal dependence of S. miltiorrhiza differed for different AM fungi. All 8 tested AM fungi were able to coexist with S. miltiorrhiza plantlets to form mycorrhizal structures, with the colonization percentage generally high (54.83%-89.97%). S. miltiorrhiza showed no mycorrhizal dependence on Acaulospora laevis or Glomus tenebrosum. After inoculation with AM fungi, the biomass and fresh weight of most S. miltiorrhiza test plants increased, indicating that inoculation with AM fungi had a promotional effect on the root accumulation of S. miltiorrhiza. Different AM treatment groups affected the biomass production of S. miltiorrhiza differently (P<0.05). Among the single strain treatments, treatment 34 (G) had the best effect, while among the mixed strain treatments, [name the AMS in this treatment] (Treatment 20) (ACE) had the most significant promotion effect on dry matter accumulation of S. miltiorrhiza. Similarly, different AM fungi affected soil enzyme activity differently (P<0.05). Among the single strain treatment groups, the G. tenebrosum group most increased the activity of invertase and phosphatase, and the Glomus formosanum group most increased urease activity. In the mixed strain treatment group, Treatment 20 most increased the activity of urease and sucrase, while treatment 17 (ABD) most increased the activity of phosphatase. Cluster analysis of the 35 treatment combinations yielded three groups based on the degree of growth promotion: strong growth promotion, low growth promotion and no growth promotion. Considering the achieved infection rate, mycorrhizal dependency, plant yield and soil enzyme activity, mixed inoculation with [name AM strains] has strong growth-promoting effects and so would be the best candidate treatment for the development of fungicides. However, Treatment 20 was overall the best combination, and this treatment resulted in some improvement in rhizosphere soil fertility, improved soil microenvironment. This research provides a theoretical basis for alleviating obstacles to continuous cropping of S. miltiorrhiza.

Key words: dry matter, arbuscular mycorrhizal fungi, rhizosphere soil, colonization percentage