Abstract: Scorzonera pusilla is one of the early-spring short- lived perennial desert plants. Non-dormant seeds of S. pusilla are very small and light , and able to absorb water very quickly . Suitable temperature for germination was between 0℃ and 15℃, and the optimum temperature was 4℃ . With the increasing temperature, the germination percentage decreased evidently
. Especially , temperature fluctuations had not significant effect on seed germination. Final germination percentages decreased distinctly with decreasing water potential of PEG and NaCl solution. The relationship between water potential of different solutions and germination was negative. The stronger the osmotic stress was, the more the proline content of seedlings was. The effects of NaCl on germination and seedlings were much stronger than that of iso-osmotic PEG in spite of two different temperatures, and the proline content of seedlings confronting increasing water stress was increased sharply .When the concentration of NaCl increased to some extent , the salt toxicity occurred besides water stress . The results are valuable
to elucidate the ecogeographical patterns and mechanisms for adaptation of such early-spring ephemeral plants in the desert environments

Key words: Scorzonera pusilla

摘要： 多年生早春短命植物细叶鸦葱( Scorzonera pusilla) 种子小而轻, 吸水性强, 非休眠。对其进行变温和渗透胁迫实验, 结果为: 细叶鸦葱种子的适宜萌发温度介于0～15℃ , 以4℃为最佳; 变温对种子萌发无明显的促进作用。种子萌发率随PEG 和NaCl 溶液水势的降低而降低, 与渗透胁迫程度呈负相关。而且,在渗透胁迫下, 幼苗脯氨酸含量随胁迫程度的增强而增加。尽管温度不同, 但是等渗的NaCl 溶液对细叶鸦葱种子及其幼苗的胁迫程度大于PEG 溶液, 且表现出明显的离子毒害效应。结果对阐明荒漠区早春短命植物的生态地理格局及其干旱适应机制有着重要的理论意义。

关键词: 细叶鸦葱, 干旱适应机制, 种子, 渗透胁迫, 离子毒害效应, 脯氨酸FONT