中文摘要：

为了探讨在水分和铅交互胁迫下侧柏（Platycladusorientalis）抗性和适应能力，通过盆栽试验研究了1年生侧柏在不同水分处理（土壤相对含水量为40％、60％、80％、100％）及重金属铅（0、1000、2000、4000、6000mg·kg^-1）交互作用下叶绿素含量、电导率和叶水势的变化。结果表明：在水分和铅交互胁迫下，侧柏叶绿素含量逐渐下降，只在铅含量〉4000mg·kg^-1时与对照差异显著（P〈0．05），说明侧柏幼苗叶片的叶绿素含量对低浓度的铅含量处理不敏感，而对高浓度的铅含量处理变化敏感；在单一的水分胁迫下叶绿素含量变化与对照差异不显著，水分胁迫不是影响侧柏幼苗叶片叶绿素的主要因素。在水分和铅交互胁迫下，侧柏电导率呈上升趋势，与单一的水分胁迫相比，侧柏电导率都有不同程度的下降，适当的铅胁迫有利于提高侧柏幼苗的抗逆性。在水分和铅交互胁迫下，侧柏叶水势逐渐下降，与对照处理差异显著（P〈0．05），在土壤相对含水量为40％（重度水分胁迫）时，侧柏叶水势最小。结果表明侧柏对干旱和半干旱地区铅含量〈1000mg·kg^-1土壤环境有较好的耐受性。

英文摘要：

The resistance and adaptability of Platycladus orientalis seedlings to drought and lead interactive stress were examined. Annual seedlings were potted in the soils with different moisture contents （40%, 60%, 80%, and 100%） and lead levels （0, 1000, 2000, 4000mg· kg^- 1 , and6000mg· kg^- 1 ）. Param- eters such as the contents of chllorophill, soil electrical conductivity, leaf water potential were measured. The results showed that the chlorophyll content decreased due to interactive stress. When Pb concentra- tions were over 4 000 mg · kg^- 1 , chlorophyll content decreased significantly （p〈0.05）, which indicated that chlorophyll content were sensitive to high concentrations of Pb. With only water stress, the chloro- phyll content did not change significantly, which showed that the water stress was not the main factor to affect chlorophyll content. Compared with only water stress, the soil conductivity of interaction stress of water and Pb was lower but showing a ascendant trend, this phenomenon demonstrated that appropriate Pb stress improved the stress resistance of the seedlings. Leaf water potential decreased gradually due to interactive stress （p〈0.05）, and reached （severe stress）. The results indicated that the lowest level when the relative soil water content was 40% Platycladus orientalis seedling was well tolerant to soil with Pb concentrations 〈1 000 mg · kg^- 1 in arid and semi-arid land.