Abstract: [Objective] To investigate the effects of rehydration following drought stress on seed germination and seedling growth of Lespedeza davurica[Methods] Seeds of L. davurica. were used as experimental materials and subjected to drought stress simulated by polyethylene glycol （PEG） solutions with water potentials of 0 （control, CK）, -0.1, -0.3, -0.5, and -0.7 MPa for durations of 3, 6, 9, 12, and 14 days, followed by rehydration. The patterns of changes in germination percentage （Gp）, mean germination time （MGT）, germination index （Gi）, seedling vigor index （SVI）, radicle length （RL）, and plumule length （PL） were analyzed. [Results] With increasing PEG water potential and prolonged stress duration, Gp, Gi, SVI, RL, and PL of L. davurica seeds exhibited a declining trend, while MGT showed an increasing trend. Rehydration following short-term （3 days） drought stress at low water potential （-0.1 MPa） promoted seed germination and seedling growth of L. davurica, whereas rehydration after long-term （9-14 days） drought stress at high water potentials （-0.5 and -0.7 MPa） inhibited seed germination and seedling growth of L. davurica. [Conclusion] Seed germination and seedling growth of L. davurica can tolerate drought stress induced by PEG at water potentials below -0.5 MPa for no more than days, provided timely rehydration is applied to effectively mitigate the damage caused by drought stress.

Key words: Lespedeza davurica, drought stress, rehydration, seed germination, seedling growth, polyethylene glycol