植物生态学报 ›› 2010, Vol. 34 ›› Issue (12): 1404-1413.DOI: 10.3773/j.issn.1005-264x.2010.12.006

• 研究论文 • 上一篇    下一篇

模拟水淹对三峡库区常见一年生草本植物种子萌发的影响

王欣1,2, 高贤明1,*()   

  1. 1中国科学院植物研究所植被与环境变化国家重点试验室, 北京 100093
    2中国科学院研究生院, 北京 100049
  • 收稿日期:2010-02-24 接受日期:2010-05-31 出版日期:2010-02-24 发布日期:2010-12-28
  • 通讯作者: 高贤明
  • 作者简介:(E-mail: xmgao@ibcas.ac.cn)

Effects of simulated submergence on seed germination of four common annual herbs in the Three Gorges Reservoir Region, China

WANG Xin1,2, GAO Xian-Ming1,*()   

  1. 1State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    2Graduate University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2010-02-24 Accepted:2010-05-31 Online:2010-02-24 Published:2010-12-28
  • Contact: GAO Xian-Ming

摘要:

根据三峡水库水位运行时间, 设计了30、75、115、155、195和240天共6个水淹时间梯度(T-1、T-2、T-3、T-4、T-5和T-6), 采用模拟水淹的方法, 研究了不同水淹时间对三峡消落带4种常见的一年生草本植物稗(Echinochloa crusgali)、金狗尾草(Setaria pumila)、马唐(Digitaria sanguinalis)和荩草(Arthraxon hispidus)种子萌发的影响。结果表明: 1)随着水淹处理时间的增长, 这4种植物的萌发率基本上呈现先增高后降低的趋势。稗和荩草在T-1-T-5的种子萌发率显著高于对照(CK) (p < 0.05), T-6和CK之间差异不显著。金狗尾草T-2、T-3的萌发率显著高于CK (p < 0.05), T-1、T-4-T-6与CK之间无显著性差异。马唐在水淹处理(T-1-T-6)的萌发率均显著高于对照(CK), 但长时间水淹处理(T-4-T-6)对萌发的促进作用要低于短时间水淹处理(T-1-T-3)。这说明一定时间的水淹有利于打破种子休眠并提高种子萌发率。2)一定时间的水淹处理加快了稗、金狗尾草、马唐和荩草的萌发进程。对照组种子的日萌发率较均匀, 萌发曲线较平缓。而水淹处理的种子多集中在3-5天内大量萌发。和对照相比, 一定时间的水淹处理显著提高了这4种植物种子的萌发指数, 缩短了种子的萌发持续时间, 提早了种子萌发高峰时间和达到50%萌发率的时间。长时间的水淹对种子的萌发进程影响不大。3)总体来说, 稗、金狗尾草、马唐和荩草在各个处理下的萌发率均较高(> 40%), 可以考虑作为三峡消落带植被恢复的备选物种。

关键词: 一年生草本, 植被恢复, 种子萌发, 水淹

Abstract:

Aims Flooding disturbance can change the species composition of plant communities. Field investigation showed that annual herbs were an important part of the natural vegetation of the water-level-fluctuating zone (WLFZ) in the Three Gorges Reservoir, but there are few studies on the effects of flooding on annual plants. Annual, which reproduce from seeds, usually grow fast and can rapidly rehabilitate areas. Our objective is to determine the effects of water submergence on the germination of seeds of annuals, with regard to possible use of annual plants in vegetation restoration of WLFZ in the Three Gorges area.
Methods Seeds of four annuals, Echinochloa crusgali, Setaria pumila, Digitaria sanguinalis and Arthraxon hispidus, were collected in autumn 2008 in Wushan County of Chongqing Municipality. Seeds for control (CK) were kept in envelopes; seeds for water submergence treatments were buried in soil in plastic containers and water was poured into the containers to maintain a water layer on the soil surface. We used six different durations of water submergence, 30, 75, 115, 155, 195 and 240 days, to match water level operation of the Three Gorges Reservoir. After treatments ended, seeds were separated from soil by water flushing and filtering with gauze. The treated seeds were incubated in pots filled with soil watered daily. Three replicates of 50 seeds per sample were used for each treatment. Germinated seeds were counted daily until the end of germination.
Important findings Water submergence significantly affected seed germination rate and germination course of all four annuals. Germination rates first increased and then decreased with increased duration of submergence. Germination rates with short-time submergence treatments were significantly higher than CK. Submergence can break seed dormancy and increase the rate of seed germination. Submergence also accelerated the course of germination. Short-time submergence treatments increased germination indices significantly greater than in CK, and the germination periods were shorter, but long-time submergence had little effect on the course of seed germination. Overall, the germination rates of all treatments of all annuals were > 40%. Therefore, these four annuals are useful in vegetation restoration of WLFZ in the Three Gorges Reservoir.

Key words: annual herbs, revegetation, seed germination, submergence