中文摘要：

在未灌溉的土地上,疏叶骆驼刺（Alhagi sparsifolia）通常不能进行有性繁殖,克隆繁殖是其种群维持和延续的唯一方式。因此,克隆性及其相关克隆性状（如水分整合）在疏叶骆驼刺自然种群的维持过程中可能扮演了极其重要的角色。该文通过疏叶骆驼刺母株和子株之间的间隔子切断和给母株补充水分的方法,研究了母株和子株在各处理下的水势、叶形态和植株生长变化情况。结果表明：（1）间隔子切断后,疏叶骆驼刺母株和子株正午水势均明显增大（p〈0.01）,说明间隔子切断使得母株和子株水分亏缺值都增大。（2）给母株补水后,间隔子切断组和间隔子相连组中的母株水势均有明显增加,同时间隔子相连组的子株水势明显增加（p〈0.01）,而间隔子切断组子株水势没有明显变化（p〉0.05）。（3）间隔子切断组的子株叶片含水率明显低于间隔子相连组子株,而其株高、冠幅、分枝数和基径的增长量都明显小于间隔子相连组的子株（p〈0.01）。疏叶骆驼刺母株和子株间存在水分整合,母株会通过根系向子株传输水分。研究成果对塔克拉玛干沙漠南缘的植被恢复以及水资源的合理利用有着重要的意义。

英文摘要：

Aims Alhagi sparsifolia is one of the dominant perennial species in the extreme drought region of Taklamakan Desert in northwestern China. Alhagi sparsifolia usually cannot reproduce sexually in natural, non-irrigated envi-ronments, where the only way to maintain and extend its populations is to reproduce clonally. In the natural habi-tats, therefore, clonality and the resultant clonal traits such as clonal integration for water （i.e., water integration） may have played great roles in maintaining populations of A. sparsifolia. So far, however, few studies have been conducted to investigate the water integration pattern between mother and daughter ramets of A. sparsifolia. Methods We carried out an experiment with four treatments involving the spacer （i.e., the interconnection be-tween adjacent ramets） between mother and daughter ramets. The spacer was： （1） connected, （2） severed, （3） connected and the mother ramet was supplied with 200 L additional water, and （4） severed and the mother ramet was supplied with 200 L additional water. After 15 days of spacer severance, we measured water potential of the mother and daughter ramets and their leaf morphological and growth parameters. In the water supplement treat-ment, we measured water potential of the mother and daughter ramets immediately before and 24 h after the water supplement. We also measured soil water content at 0 cm （soil surface） to 200 cm soil depth of the mother and daughter ramets before and after water supplement. Important findings The difference of predawn water potential for both mother and daughter ramets was not sig-nificant （p 0.05） between the spacer connected and spacer severed group, but the midday water potential of both mother and daughter ramets increased significantly after spacer severance （p 0.01）. After water supplement to the mothers, water potential of mothers was significantly increased in both the spacer severance and connection treatments. Water potential of daughter ramets in spacer connectio