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作 者 ：陈阳,王贺,张福锁*,郗金标,何奕昆

期 刊 ：生态学报 2010年 30卷 2期 页码：511~518

关键词：柽柳；荒漠盐碱生境；盐分分泌；蒸腾作用；含水量；含盐量；大气湿度；

Keywords:Tamarix ramosissima Ledeb, desert saline-alkali habitat, salt secretion, transpiration, water content, ion concentration, atmosphere humidity,

摘 要 ：通过对生长于新疆盐碱生境下泌盐植物柽柳的泌盐效率, 水分盐分含量和蒸腾强度等生理指标的测定，研究内外因子对柽柳盐分分泌作用的影响。结果显示：柽柳蒸腾作用的日变化呈双峰曲线，蒸腾峰谷出现在光照最强、温度最高的中午。柽柳体内含水量和含盐量在日间变化不明显。但盐腺对盐分的分泌效率却显示出明显的变化，表现为:与8：00—10：00对较高的泌盐率相比,在光照较强和温度较高的10：00—20：00其分泌作用有所降低，在20：00—22：00光照和温度降低时泌盐率却有回升的趋势。通过对泌盐量与诸影响因子的关系进行分析发现，柽柳在日间对钠、钾、钙、镁，硫，氯离子的分泌量与大气湿度呈现出很好的正相关性。盐腺在白天对各离子的分泌作用强于夜间。柽柳泌盐量与叶片含盐量的关系则表现出尽管柽柳叶片钠、硫元素的含量高于钙、钾、镁、氯元素，但对钠、氯离子的分泌作用却强于其它离子。与叶含盐量相比，盐腺对氯离子的相对分泌作用最强，对钠离子其次，对钾，硫离子的相对分泌作用较弱，对钙，镁离子的分泌最低。因此，柽柳对盐分的分泌作用受到植物体盐分含量及外界环境条件共同影响，其盐腺对不同离子的分泌作用具有很强的选择性。

Abstract:The effects of various internal and environmental factors on ion excretion were investigated on Tamarix Ramosissima Ledeb, a kind of recretohalophytes which growed naturally under saline habitat in Xin Jiang province. The ion secretion rates, ion concentrations, water contents and transpiration rates of Tamarix leaves were determined. The daily variations in the transpiration rates of Tamarix exhibited two peaks curves, and the peak-valley was found to occur in the middle part of the day with the strongest photo-radiation and the highest temperature. The water and ion content in leaves appeared to be nearly constant，whereas the rates of excreted ions varied significantly during day. The ionic excretion patterns of fluctuation during day showed that: the rates of ion secretion were higher between 8:00 and10:00. and then decreased gradually during 10:00 and 20:00 with the higher photo-radiation and temperature. But the rates of ion secretion increased up after 20:00 O′clock with the declining photo-radiation and temperature. By analyzing the factors that affected the ion secretion, there was a general positive correlation between atmosphere humidity and ion secretion during the day. The amount of ion secretion was found to be higher during the day than during the night. When compared the ion secreted amount with the ion concentration on the leaves, It showed the predominant ions secreted were sodium and chloride although the main ions accumulated in leaves were sodium and sulfur，the concentration of which were found to be higher than those of potassium, calcium,magnesium and chloride. If the relative secretion could be defined by the ratio between the ion concentration secreted and that in the leaves, the maximal relative excretion was chloride, followed by sodium, and a somewhat the lower were potassium and sulfur, the lowest were calcium and magnesium. The results above indicated that both ionic content in leaves and ecophysiological environment conditions had effects on ion excretion. And the secretion of Tamarix glands exhibited highly selective character for various ions.

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