Abstract: To study theeffects of phenanthrene on physiology and biochemistry of Salix viminalis, a hydroponic experiment was conducted with cutting seedlings under different concentrations of phenanthrene(0.2, 0.5, 1.0 and 1.2 mg·mL^-1), and 1.0 mg·L^-1 phenanthrene was treated for 16days to measure the changes of photosynthetic characteristics and osmotic regulatory substances. The results showed that high concentration of phenanthrene significantly inhibited the plant height and root vigor of Salix viminalis, and increased conductivity and membrane permeability.Under the stress of 1.0 mg·L^-1 phenanthrene, photosynthesis was inhibited with photochemical quenching (qP) decreased significantly, and the light reaction was influenced;stomatal conductance (Gs), intercellular CO₂ concentration (Ci), and rubisco enzyme activity decreased, resulting in reduced CO₂ supply and assimilation, thereby suppressing dark reactions. The biggest photochemical efficiency (F_v/F_m) and PSⅡ potential activity (F_v/F₀) of leaves did not change significantly,indicating that the ability of using solar power and potential activity of PSⅡwas not affected. Among the osmoregulatory substances, proline and soluble sugar were important regulatory substances for plant to resist phenanthrene stress. The results would provide the basis for revealing the toxicity mechanism of PAHs on Salix viminalis and strengthening the research on plant environmental restoration.

Key words: Salix viminalis, phenanthrene, photosynthetic characteristics, osmoregulatory substance

摘要： 为研究菲对蒿柳生理生化的影响,以蒿柳扦插苗为试验材料,采用水培的方式,测定不同浓度(0.2、0.5、1.0和1.2 mg·L^-1)菲对蒿柳株高及生理的影响,并选取对植物生长有显著抑制作用的最低浓度(1.0 mg·L^-1)菲对蒿柳进行16 d的处理,测定其光合特性及渗透调节物质的变化。结果表明,高浓度菲处理显著抑制了蒿柳的株高和根系活力,使其电导率升高,膜透性增大。1.0 mg·L^-1菲胁迫下,蒿柳的光合作用受到抑制,光化学淬灭系数(qP)显著下降,光反应受到影响;气孔导度(Gs)和胞间CO₂浓度(Ci)下降、Rubisco活性降低,导致CO₂供应和同化减少,暗反应受到抑制。叶片的最大光化学效率(F_v/F_m)和PSⅡ潜在活性(F_v/F₀)无显著变化,说明PSⅡ利用光能的能力和潜在活性未受到影响。渗透调节物质中,脯氨酸和可溶性糖是植物抵御菲胁迫的重要调节物质。本研究结果为揭示多环芳烃(PAHs)对蒿柳产生的毒害机制及加强植物对环境的修复研究提供了依据。

关键词: 蒿柳, 菲, 光合特性, 渗透调节物质