Li Qiang, Gao Xiang, Ding Wu-quan, Zhu Qi-hong, Ou Yuan, Liu Yu
College of Chemistry and Environmental Engineering, Chongqing University of Arts and Sciences, Chongqing 402160, China.
Huan Jing Ke Xue. 2012 Aug;33(8):2628-33.
Acorus calamus L. is a common kind of wetland plant species in the Three Gorges Reservoir. In this study, we investigated the influence of perennial flooding on growth restoration of A. calamus in the lightless conditions and the drought stress on this plant species' growth after flooding. Our research provided the scientific basis for the selection of candidate species for vegetations restoration in water-level-fluctuation zone of the Three Gorges Reservoir. A. calamus plants were exposed to waters in the lightless conditions in September 2009 and September 2010 respectively and taken away from the waters and grew in natural conditions in the following March, April and May (named as S1, S2, S3). All plants in the control, S1 and S2 groups were challenged with drought stress in May for 20 days. During the experiment, the plant number and leaf number were recorded regularly, as well as leaf length and leaf width. The results showed that flooding restrained the germination of the plants with much less plant in flooding groups than the control, and the plant germination rate had inverse relation to the flooding time. Flooding promoted formation and elongation of the leaves in S1 and S2 groups, which showed higher leaf growth parameters, such as leaf length, leaf number, total leaf length of one plant and total leaf length of all plants than the control. However, all of these growth parameters in S3 group had significantly lower values compared to the control. The survival rate of the plants after flooding decreased significantly with longer flooding time. Besides, the leaf length and leaf width in S1 and S2 groups increased significantly but with decreased leaf number. Additionally, all growth parameters (leaf length, leaf width, leaf number, total leaf number, total leaf length of one plant, total leaf length of all plants) in S3 group decreased remarkably. Furthermore, drought decreased the values of all growth parameters and the plant number in the control, S1 and S2 groups notably. When drought stress was removed for 25 days, the leaf number in the control, S1 and S2 groups increased by 67.0% (P < 0.05), 66.7% (P < 0.05) and 36.2% (P < 0.05), respectively, and the total leaf length of one plant, total leaf length of all plants and total leaf number in S1 and S2 groups increased by 48.2%, 18.1%, 66.7%, 35.0%, 75.0% and 64.3%, respectively (P < 0.05). Therefore, A. calamus exhibited not only strong adaption and tolerance to flooding,but also robust growth restoration ability after flooding, as well as good restoration ability to the drought stress. In summary, A. calamus could be used as one kind of restoration or reconstruction species in water-level-fluctuation zone (especially not exposed to flooding in March or April) of the Three Gorges Reservoir.
菖蒲是三峡水库常见的湿地植物物种。在本研究中，我们调查了常年水淹对菖蒲在无光条件下生长恢复的影响，以及水淹后干旱胁迫对该植物物种生长的影响。我们的研究为三峡水库消落带植被恢复候选物种的选择提供了科学依据。菖蒲植株分别于2009年9月和2010年9月在无光条件下置于水中，次年3月、4月和5月取出并在自然条件下生长（分别命名为S1、S2、S3）。对照组、S1组和S2组的所有植株在5月均遭受了20天的干旱胁迫。在实验过程中，定期记录植株数量和叶片数量，以及叶片长度和宽度。结果表明，水淹抑制了植株的萌发，水淹组的植株数量远少于对照组，且植株萌发率与水淹时间呈负相关。水淹促进了S1组和S2组叶片的形成和伸长，其叶片生长参数如叶片长度、叶片数量、单株总叶长和所有植株总叶长均高于对照组。然而，S3组的所有这些生长参数均显著低于对照组。水淹时间越长，水淹后植株的存活率显著降低。此外，S1组和S2组的叶片长度和宽度显著增加，但叶片数量减少。另外，S3组的所有生长参数（叶片长度、叶片宽度、叶片数量、总叶片数、单株总叶长、所有植株总叶长）均显著下降。此外，干旱显著降低了对照组、S1组和S2组的所有生长参数值和植株数量。当去除干旱胁迫25天后，对照组、S1组和S2组的叶片数量分别增加了67.0%（P<0.05）、66.7%（P<0.05）和36.2%（P<0.05），S1组和S2组的单株总叶长、所有植株总叶长和总叶片数分别增加了48.2%、18.1%、66.7%、35.0%、75.0%和64.3%（P<0.05）。因此，菖蒲不仅对水淹表现出较强的适应和耐受能力，而且在水淹后具有较强的生长恢复能力，对干旱胁迫也具有良好的恢复能力。综上所述，菖蒲可作为三峡水库消落带（特别是3月或4月不遭受水淹）的一种恢复或重建物种。
