植物生态学报 ›› 2011, Vol. 35 ›› Issue (3): 237-246.DOI: 10.3724/SP.J.1258.2011.00237

• 研究论文 •    下一篇

三峡水库消落区4种一年生植物种子的水淹耐受性及水淹对其种子萌发的影响

申建红, 曾波*(), 类淑桐, 苏晓磊, 黄文军   

  1. 三峡库区生态环境教育部重点实验室, 重庆市三峡库区植物生态与资源重点实验室, 西南大学生命科学学院, 重庆 400715
  • 收稿日期:2010-02-09 接受日期:2011-01-04 出版日期:2011-02-09 发布日期:2011-03-02
  • 通讯作者: 曾波
  • 作者简介:*E-mail: bzeng@swu.edu.cn

Seed submergence tolerance of four annual species growing in the water-level-fluctuation zone of Three Gorges Reservoir, China, and effects of long-term submergence on their seed germination

SHEN Jian-Hong, ZENG Bo*(), LEI Shu-Tong, SU Xiao-Lei, HUANG Wen-Jun   

  1. Key Laboratory of Eco-environment in Three Gorges Reservoir Region of Ministry of Education, Chongqing Key Laboratory of Plant Ecology and Resources Research in Three Gorges Reservoir Region, School of Life Science, Southwest University, Chongqing 400715, China
  • Received:2010-02-09 Accepted:2011-01-04 Online:2011-02-09 Published:2011-03-02
  • Contact: ZENG Bo

摘要:

稗(Echinochloa crusgalli)、苍耳(Xanthium sibiricum)、合萌(Aeschynomene indica)和水蓼(Polygonum hydropiper)是三峡水库消落区常见的4种一年生植物。该研究旨在验证这4种植物的种子能否耐受三峡水库消落区的水淹环境及种子在消落区变化的环境中能否成功地萌发。将消落区按照吴淞高程标准划分为9个高程梯度(145-150 m、150-155 m、155-160 m、160-163 m、163-166 m、166-169 m、169-172 m、172-175 m和>175 m), 实地播种这4种植物的种子(或果实), 并将种子萌发划分为“有泥沙淤积于种子表面”和“无泥沙淤积于种子表面” 2组。观察在消落区水位变化(蓄水到退水)一个周期内种子能否耐受水淹及水淹对不同高程种子萌发的影响。结果发现: (1)稗、苍耳、合萌和水蓼的成熟种子(或果实)能够耐受三峡水库消落区的水淹环境并保持活力。(2)这4种一年生植物种子的萌发起始时间和萌发持续时间都随着高程的降低而逐渐缩短(p < 0.01); 高程169 m以下, 种子萌发的起始时间显著缩短(p < 0.01)。总体来看, 在同一高程区域内, 合萌种子的萌发起始时间略长一些, 苍耳次之, 水蓼最短。(3)对稗、苍耳和水蓼的种子而言, 萌发率随高程的降低总体上呈现先上升后下降的趋势。合萌的种子萌发率随高程的降低总体呈下降的趋势。(4)水淹过程中产生的泥沙淤积对种子萌发影响较小, 但是在一定程度上可以促进苍耳的种子萌发而抑制合萌的种子萌发。以上试验结果表明: 这4种一年生植物的种子(或果实)在三峡水库消落区变化环境中能够耐受水淹并成功地萌发, 可应用于三峡水库消落区的植被恢复和生态重建中。

关键词: 合萌, 稗, 水蓼, 植被恢复, 种子萌发, 水淹, 耐受, 苍耳

Abstract:

Aims Our objective was to examine seeds of Echinochloa crusgalli, Xanthium sibiricum, Aeschynomene indica and Polygonum hydropiper, four common annual species growing in the water-level-fluctuation zone of Three Gorges Reservoir in China, in regard to tolerance of submergence and germination in the changing environment of the zone.
Methods We divided the water-level-fluctuation zone into nine elevational zones according to the Wusong Elevation criterion. We then observed seed submergence tolerance and the effects of submergence on seed germination in a “water impoundment-water recession” cycle after seeds of the four species were sown in the nine elevational zones. Seed germination was divided into seeds with and without sand sediment on surface.
Important findings Ripe seeds (or fruits) of the four species kept their vitality after submergence. The starting time for seed germination after the end of submergence and seed germination duration both gradually decreased with decreasing elevation (p < 0.01), and the starting time for seed germination was significantly reduced below 169 m (p < 0.01). Overall, within the same elevational zone, the starting time for seed germination after the end of submergence was longest for A. indica, followed by X. sibiricum, and shortest for P. hydropiper. For E. crusgalli, X. sibiricum and P. hydropiper, seed germination percentage first increased and then decreased with decreasing elevation, while it decreased for A. indica. Sand sedimentation had little effect on seed germination; the effect was positive for X. sibiricum and negative for A. indica. We concluded that seeds (or fruits) of the four annuals can tolerate submergence and germinate successfully in the changing environment of water-level-fluctuation zone. Therefore, these species are useful in the revegetation and restoration of this zone of the Three Gorges Reservoir.

Key words: Aeschynomene indica, Echinochloa crusgalli, Polygonum hydropiper, revegetation, seed germination, submergence, tolerance, Xanthium sibiricum