中文摘要：

在臭柏长期室内石砾土栽培条件下,通过培养液中加入PEG以调节溶液渗透势,设置对照区（pF值3.0）、水分胁迫区（pF值2.3）2种处理,并分别从匍匐茎中部人工培养不定根,测定有不定根和无不定根匍匐茎小枝的蒸腾速率、气孔导度及其水势的日变化和叶片水分特性。结果表明：1）在水分胁迫条件下,匍匐茎先端小枝通过降低正午水势提高吸水能力;基部小枝通过控制蒸腾,维持枝条水势防止失水。2）有不定根的匍匐茎通过降低质壁分离时的水势（ψtwlp）和充分吸水时的渗透势（ ψssat）提高吸水能力,而且增加细胞弹性率,迅速降低膨压保证失水时能尽快关闭气孔;而无不定根匍匐茎虽然吸水能力较差,但细胞壁柔软,即使蒸腾失水,也能在较长时间内维持膨压,保证生命活动进行。

英文摘要：

The stolons with and without adventitious roots of Sabina vulgaris were grown under controlled conditions of the pF 3.0 and pF 2.3 treatments by using PEG（polyethylene glycol） in their culture solutions. Diurnal changes of transpiration rate,stomatal conductance and water potential were measured. Leaf water relations were analyzed by Pressure-Volume curve. The results showed that：branches growing on the top part of stolons increased the ability of water absorption by lowering minimum potential under water stress. On the other hand, the constant leaf water potential of branches growing on the base part of stolons was maintained by controlling the transpiration under water stress. The stolon branches with adventitious roots uptake by decreasing water potential at turgor loss point （ ψtwlp ） and osmotic potential at full turgidity （ ψssat ）. Moreover, the rapid response of stomata avoided excessive loss of water under stress. There was high bulk modulus of elasticity （ ε ） of its cell wall. The stolon branches without adventitious roots showed the lower ability of water absorption under water stress conditions, but they were able to tolerate water stress with their soft cell wall which could make them to maintain a constant turgor pressure under severe water loss conditions.