| Seeds of Taraxacum kok-saghyz Rodin (TKS) were employed as the experimental material in this paper, and the effects of simulated drought stress with different concentrations and osmotic potentials (-1.0～0.0 MPa) by polyethylene glycol (PEG-6000) were investigated on seed germination potential, seed germination rate, seed daily germination rate, average seed germination rate, germination index, viability index, radicle length, germ length and germ width. The results showed that the variation trend of seed activity and seedling growth of TKS was firstly ascending and then gradually dropping with the levels and time of simulated drought stress by PEG increased. When osmotic potential of PEG reached -0.4 MPa, TKS seeds germination was promoted, and their germination index and viability index were significantly higher than the CK group. However, the differences in radicle length, germ length and germ width tested in this research were not significant from the CK group, indicating that the seed activity might be more sensitive to PEG-simulated drought stress than seedling growth. The seeds treated with -0.8 MPa osmotic potential by PEG could not germinate at all, suggesting that -0.8 MPa osmotic potential was critical for the seed germination of TKS. |