| To investigate the responses of wild groundcover plants to drought stress, Glycine soja and Allium mongolicum were used as experimental materials and subjected to different levels of drought stress in a gradient design. Physiological and biochemical indices were measured under each treatment to evaluate drought resistance characteristics. The results showed that chlorophyll contents in both species increased at first and then decreased as drought duration increased. The maximum values occurred after 5 days of drought stress, indicating that photosynthetic activity was maintained at a relatively stable level during the early stage of drought stress. Relative leaf water content in both species declined progressively as drought stress intensified. However, the decrease in A. mongolicum was smaller than that observed in G. soja, suggesting a stronger water retention capacity in A. mongolicum. Soluble sugar contents in both species increased continuously with prolonged drought stress, and the soluble sugar content of A. mongolicum reached a maximum value of 40.85 mg/g after 15 days of drought treatment. With increasing drought duration, malondialdehyde (MDA) content in G. soja showed a continuous increase, whereas MDA content in A. mongolicum increased initially and then decreased, reaching a peak value of 121.87 nmol/g on the 15th day of drought stress. Overall, the magnitude of MDA accumulation in A. mongolicum was lower than that in G. soja, indicating less membrane lipid peroxidation damage under drought conditions. These results demonstrate that A. mongolicum exhibits stronger drought resistance than G. soja, primarily due to its greater water retention capacity and enhanced physiological regulation under drought stress. |
