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中国沙漠 ›› 2012, Vol. 32 ›› Issue (3): 744-749.

• 生物与土壤 • 上一篇    下一篇

水分对科尔沁沙地差不嘎蒿气体交换特性的影响

李熙萌, 冯金朝*, 周芸芸, 朱发厅   

  1. 中央民族大学 生命与环境科学学院, 北京 100081
  • 收稿日期:2011-11-01 修回日期:2011-11-24 出版日期:2012-05-20 发布日期:2012-05-20

Effects of Water Supply Condition on Gas Exchange Characteristics of Artemisia halodendron in Horqin Sandy Land

LI Xi-meng, FENG Jin-zhao, ZHOU Yun-yun, ZHU Fa-ting   

  1. College of Life and Environmental Science, Minzu University of China, Beijing 100081, China
  • Received:2011-11-01 Revised:2011-11-24 Online:2012-05-20 Published:2012-05-20

摘要: 以科尔沁沙地优良固沙植物差不嘎蒿(Artemisia halodendron)为实验对象,研究了其在不同水分条件下的气体交换特性。结果表明,不同水分处理下差不嘎蒿的气体交换特性存在显著差异。在对照供水条件(当地降水平均值,123 mm)下,差不嘎蒿叶片具有最大的光合速率;少量供水(61.5 mm)下,差不嘎蒿叶片的气体交换能力下降,导致净光合速率减小,但水分利用率升高,显示出对干旱环境的强适应能力,净光合速率日变化曲线为双峰型,具有光合“午休”现象;大量供水(184.5 mm和246 mm)下,叶片气体交换能力增强,但净光合速率和水分利用率较小,净光合速率日变化曲线为单峰型,光合“午休”现象消失。根据Farquhar和Sharkey的观点,相对于对照处理,可以判定少量供水条件下影响差不嘎蒿净光合速率的因素以气孔因素为主,而充分供水条件下则以非气孔因素为主。

关键词: 差不嘎蒿, 供水条件, 气体交换, 光合&ldquo, 午休&rdquo

Abstract: The effects of four water supply levels on gas exchange characteristics of Artemisia halodendron were studied. Results show that the gas exchange characteristics are significantly different under different water supply treatments. Under the water supply level equal to the monthly average precipitation (123 mm), the leaves of A. halodendron have the highest net photosynthetic rate (Pn). Little water supply (61.5 mm) makes the gas exchange ability of leaves to decline, which leads to Pn decrease and water use efficiency (WUE) increase, and the diurnal change of Pn is showed as a double-peak curve with a significant midday depression. The increase of water use efficiency (WUE) means a strong adaptability of this plant to drought stress. In contrast, much water supply (184.5 mm; 246 mm) leads to increases of the gas exchange ability and relative decrease of Pn and WUE, and the diurnal course of Pn is showed as a single-peak curve without midday depression. Compared with Pn under the water supply level equal to the monthly average precipitation, Pn decreases under little water supply, which is attributable to stomatal factor according to views of Farquhar and Sharkey, while the decrease of Pn under much water supply is attributable to non-stomatal factors.

Key words: Artemisia halodendron, water supply condition, gas exchange, midday depression of photosynthesis

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