植物生态学报 ›› 2015, Vol. 39 ›› Issue (1): 92-103.DOI: 10.17521/cjpe.2015.0010

所属专题: 入侵生态学

• • 上一篇    下一篇

三种盐胁迫对互花米草和芦苇光合作用的影响

胡楚琦, 刘金珂, 王天弘, 王文琳, 卢山, 周长芳*()   

  1. 南京大学生命科学学院医药生物技术国家重点实验室, 南京 210093
  • 收稿日期:2014-07-21 接受日期:2014-12-09 出版日期:2015-01-10 发布日期:2015-01-22
  • 通讯作者: 周长芳
  • 作者简介:

    # 共同第一作者

  • 基金资助:
    基金项目 国家自然科学基金(30970458)

Influence of three types of salt stress on photosynthesis in Spartina alterniflora and Phragmites australis

HU Chu-Qi, LIU Jin-Ke, WANG Tian-Hong, WANG Wen-Lin, LU Shan, ZHOU Chang-Fang*()   

  1. State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, China
  • Received:2014-07-21 Accepted:2014-12-09 Online:2015-01-10 Published:2015-01-22
  • Contact: Chang-Fang ZHOU
  • About author:

    # Co-first authors

摘要:

互花米草(Spartina alterniflora)的入侵给海岸带盐沼生态系统的结构和功能带来了显著影响。互花米草盐沼中的硫含量高于附近的土著芦苇(Phragmites australis)盐沼。为探讨硫元素对互花米草和芦苇竞争过程的可能影响及其作用机制, 以50 mmol·L-1的Na2SO4和Na2S对互花米草和芦苇进行处理, 分析处理前后5天内两种植物光合气体交换和叶绿素荧光指标变化的差异, 实验另设等Na+浓度的NaCl处理作为比较。研究发现: Na2S对互花米草和芦苇光合作用影响的差异最大, NaCl次之, Na2SO4最小。Na2S处理后, 互花米草净光合速率(Pn)出现显著上升, 芦苇Pn值大幅度下降。互花米草的光饱和点(Isat)上升而芦苇的Isat值无变化。表明Na2S处理对互花米草的光合能力有促进作用, 但对芦苇的光合能力有抑制作用。NaCl处理后互花米草Pn值也出现小幅上升, 而芦苇Pn值略有下降。Na2SO4处理对互花米草和芦苇的Pn值均无显著影响。除Na2SO4处理的互花米草外, 不同盐处理后的互花米草和芦苇非光化学淬灭(NPQ)均出现上升趋势。研究结果表明互花米草对环境硫胁迫的适应能力显著高于芦苇, 暗示盐沼高硫环境尤其是硫化物有助于互花米草相对于芦苇的竞争, 也很可能是其形成单一植被的重要原因之一。

关键词: 生物入侵, 盐沼生态系统, 互花米草, 芦苇, 硫环境, 盐胁迫, 光合作用

Abstract: Aims

The invasion of Spartina alterniflora has imposed significant influences on structure and functioning of coastal saltmarshes. The Spartina marsh has been found to contain relatively higher sulfur content than the adjacent native Phragmites marsh. This research is aimed to investigate if sulfur helps with S. alterniflora in competition over Phragmites australis.

<i>Methods</i>

Seedlings of S. alterniflora and P. australis were grown in an imitated mesocosm on the campus of Nanjing University. Three common salts of the sea water, Na2SO4, Na2S and NaCl were respectively added to the cultural medium. Light response curves of the plants before and during the four days of treatments were obtained by measuring gas exchange with varying light levels. Maximum quantum yield of photosynthesis II (PSII) and light induction curves were also measured by chlorophyll fluorescence analysis.

<i>Important findings</i>

Among the three salts, Na2S caused the greatest difference in the response of photosynthesis between S. alterniflora and P. australis, and Na2SO4 had the least effect. The Na2S treatment significantly increased net photosynthetic rate (Pn) and light saturation point (Isat) in S. alterniflora, but decreased Pn in P. australis. The NaCl treatment also increased Pn in S. alterniflora to a less degree and decreased Pn in P. australis. The Na2SO4 treatment had little effect on Pn in both S. alterniflora and P. australis. The non-photochemical quenching (NPQ) in P. australis were promoted by all three salts, whereas it was only affected by Na2S and NaCl in S. alterniflora. Our results suggest that S. alterniflora has significantly greater tolerance to sulfate and sulfide than P. australis. Therefore, sulfuric compounds and especially sulfide in saltmarsh environments might benefit the competition of S. alterniflora over P. australis, which could contribute to the formation of the mono-specific vegetation of the invasive S. alterniflora.

Key words: biological invasion, saltmarsh ecosystem, Spartina alterniflora, Phragmites australis, sulfur enviroment, salt stress, photosynthesis