The Effects of Low-Temperature Stress on the Physiological Characteristics and Active Components of Ginseng Under Different Soil Moisture Conditions

Ginseng growth is susceptible to environmental stresses, particularly the frequent occurrence of low temperatures and water fluctuations in spring in Northeast China, which often lead to a decline in medicinal yield and quality. This study systematically analyzed the physiological response characteristics and variation patterns of active components under dual stresses of low temperature and water. The aim was to elucidate the adaptation mechanism of ginseng to abiotic stresses, providing a theoretical basis for optimizing ginseng cultivation management practices and enhancing the quality of medicinal materials. In this study, 2-year-old and 4-year-old ginseng roots were selected as research materials. They were subjected to treatments of low soil moisture (20–30%), medium soil moisture (40–50%), and high soil moisture (60–70%). Low-temperature treatments were conducted at 0 °C for different durations (4 h, 24 h, 33 h, 48 h). Physiological indicators of the ginseng roots were determined at each time point, and the active components of ginseng roots in the control and treatment groups were investigated. The results indicated significant differences in osmotic adjustment substance changes between 2-year-old and 4-year-old ginseng roots. The content of superoxide dismutase (SOD) increased during low-temperature stress in both age groups. An increase or decrease in soil moisture significantly enhanced the accumulation of total ginsenosides. However, low-temperature stress notably reduced the accumulation of total ginsenosides. Nevertheless, after low-temperature treatment, the PPT-type ginsenosides in the high soil moisture group showed a significant increase. The findings of this study provide a scientific basis for improving the medicinal component content of ginseng and offer theoretical support for future water management practices.