Abstract: Bryophytes under good health is the biological foundation for the formation and development of moss crusts. Soil microorganisms play a crucial role in driving plant growth, development, and health. We clarify the effects of soil microorganisms on Didymodon vinealis, a dominant moss species in biocrusts on the Loess Plateau. Using sterilization-inoculation incubation experiments, we conducted a 30-day indoor culture to investigate the effects and underlying mechanisms of soil microorganisms on key growth and developmental indicators of mosses, including plant height, number of new gametophytes, and gametophyte germination rate. The results showed that sterilization significantly reduced soil microbial biomass carbon and the activities of β-1,4-glucosidase, N-acetyl-β-D-glucosaminidase, and alkaline phosphatase, thereby suppressing the growth and vegetative propagation of D. vinealis. New gametophytes of D. vinealis began to germinate 3-5 days after inoculation. The period around day 15 represented the critical stage for gametophyte germination, while the rapid height growth of moss occurred at day 25. The inhibitory effect of soil microorganisms (sterilization treatment) on the growth of D. vinealis exhibited a phased pattern. After 15 days of cultivation, the germination of D. vinealis was inhibited, with a maximum inhibition rate of 22.5%. After 25 to 30 days of cultivation, the main inhibition was on plant height growth, with a maximum inhibition rate of 29.2%. Sterilization reduced soil enzyme activities and inhibited the growth and vegetative reproduction of D. vinealis, while inoculating with D. vinealis could promote microbial recovery in sterilized soil. This study explored the pathways through which soil microorganisms influenced vegetative reproduction and gametophyte growth of bryophytes, thus providing a theoretical basis for the artificial cultivation of moss crusts.

Key words: microorganism, sterilization, enzyme activity, biocrusts, Didymodon vinealis