塔里木河下游干旱胁迫下的胡杨生理特点分析

本运用塔里木河下游地下水位变化资料和塔里木河下游主要植物胡杨脯氨酸和脱落酸(ABA)的分析实验数据，结合野外调查，对地下水位变化与胡杨体内脯氨酸和脱落酸积累的关系进行了分析。研究表明，在塔里木河下游，塔里木河下游胡杨体内的脯氨酸和脱落酸含量与地下水位变化密切相关．以胡杨为主的天然植物受干旱胁迫程度愈大，退化愈严重，而反映在胡杨体内脯氨酸和脱落酸含量上．则随着地下水位的下降、水分胁迫程度的增加呈现出明显增加态势。在不同地下水位埋深条件下，胡杨体内脯氨酸和脱落酸累积过程的变化和差异表达了胡杨受干旱的程度；塔里木河下游胡杨的生长发育已受到严重的十旱胁迫。

Analysis on the physiological characteristic of Populus euphratica under drought stress in the lower reaches of Tarim River

Taking the Populus euphratica distributed in the lower reaches of Tarim River as a study sample, the relationship between proline, abscisic acid content of P.euphratica and different groundwater levels is particularly analysed at Yahepu, Yingsu and Aragan sectiones in this paper. The result shows that the relationship between proline, abscisic acid content of P.euphratica and different groundwater level at Yahepu, Yingsu section is consistent with that at Aragan section, namely while groundwater level drops, the proline and abscisic acid content of P.euphratica will increase; maybe two factors bring about the result. One is that there is positive relativity between proline, abscisic acid content and degree of water stress. The other is that groundwater is most pivotal water source for growth of P.euphratica at lower reaches of Tarim River. The result also shows that there is difference in increased extent of proline and abscisic acid content of P.euphratica under different ground water levels condition. Proline and abscisic acid content in P.euphratica body will accumulate along with aggravation of drought stress, which is feedback for P.euphratica to adapt to drought adversity and is manner for P.euphratica to resist drought and maintain itself normal life activity. Accumulation of proline and abscisic acid is in favor of resist-drought ability of P.euphratica when it suffers drought stress. The conclusion shows that growth of P.euphratica already has suffered water stress at lower reaches of Tarim River.