Adaptive strategies and biochemical responses of Rhus tripartita populations under contrasting environments in Saudi Arabia
摘要
Seed germination and seedling responses of six Rhus tripartita populations were evaluated to understand their adaptive potential under arid conditions. This study is the first to investigate the germination dynamics and drought tolerance of this species in Saudi Arabia, providing Insights that may assist conservation strategies and future reintroduction initiatives in degraded environments. Six seed populations were subjected to salinity and drought stress using iso-osmotic potentials ranging from control to -1.5 MPa of NaCl or PEG6000. Germination rate, time to reach 50% germination (T50), and seedling growth were recorded. Seed germination declined progressively with increasing salinity, with the highest germination observed under control conditions, while a substantial reduction occurred at -1.5 MPa. Populations 2 and 4 showed superior drought tolerance compared to populations 1, 3, 5 and 6. Drought stress also significantly affected the time to reach T50 and reduced seedling growth. Exposure to drought stress delayed the attainment of T50 and resulted in reduced seedling growth. In contrast, leaf proline and soluble sugar concentrations increased under water stress, indicating the accumulation of osmoprotective solutes. These results reveal inter-population variability in germination and physiological responses, highlighting populations 2 and 4 are particularly suitable for artificial regeneration and restoration programs in arid regions. Overall, the results provide insights into the ecological strategies of Rhus tripartita and support its sustainable management under challenging environmental conditions.