| 摘要: |
| 近几十年来，受到人类活动和气候变化的影响，全球海草床呈现退化趋势，海草床的恢复备受关注。其中，海草种子或幼苗移植由于其对供体海草床破坏和影响较小，并能保证海草的遗传多样性而备受重视。移植区的底质类型是决定海草种子或幼苗移植存活率的重要因子，然而，目前关于热带海草种子萌发和幼苗生长对不同底质类型响应的研究很有限。本研究以热带海草海菖蒲（Enhalus acoroides）种子为研究对象，利用室内模拟实验，分别设置细砂和砂砾底质的处理，探讨不同底质类型对海菖蒲种子萌发和幼苗生长的影响。研究发现，细砂组和砂砾组的萌发率和萌发历期的平均值分别96.3%、3.6 d和95.0%、3.4 d，两个处理组之间差异不显著。萌发后的细砂组海菖蒲幼苗的存活率为97.37%，而砂砾组的幼苗存活率仅为81.58%；另外，海菖蒲幼苗的叶片长度、根长度、叶片生长速率和根生长速率在细砂组均显著高于砂砾组。因此，沉积物粒径的差异对海草种子的萌发率和萌发时间没有显著性影响，但沉积物粒径增大会显著降低萌发后海菖蒲幼苗的存活率和生长速率。因此，未来开展海菖蒲种子或幼苗的野外移植，应选取沉积物粒径较小细砂质区域进行移植，可促进海菖蒲种子或幼苗移植的成活率，提高海菖蒲生态修复的成功率。 |
| 关键词: 海洋生物学 海菖蒲 底质类型 种子 萌发 幼苗 |
| DOI：10.3969/J.ISSN.2095-4972.2021.01.008 |
|
| 基金项目:广州市科技计划资助项目（201904010370）；中国科学院战略性先导科技专项资助项目（XDA13020204）；南方海洋科学与工程广东省实验室（广州）人才团队引进重大专项资助项目（GML2019ZD0404）；海南省重点研发计划资助项目（ZDYF2020180）；中国科学院南海生态环境工程创新研究院自主部署项目资助项目（ISEE2018PY01,ISEE2018ZD02）；国家自然科学基金资助项目（41806147） |
|
| Effects of different sediment types on the seed germination and seedling growth of tropical seagrass, Enhalus acoroides |
| LIU Song-lin,JIANG Zhi-jian,WU Yun-chao,ZHANG Xia,HUANG Xiao-ping |
| (Key Laboratory of Tropical Marine Bioresources and Ecology, South China Sea Institute of Oceanology, CAS, Guangzhou 510301, China;Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; Innovation Academy of South China Sea Ecology and Environmental Engineering, CAS, Guangzhou 510301, China;Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, South China Sea Institute of Oceanology, CAS, Sanya 572100, China) |
| Abstract: |
| In recent decades, natural and anthropogenic disturbances in coastal areas have resulted in a world-wide decline of tropical seagrass meadows. Thus the recovery of seagrass meadow has gained more attention. Therein, the seagrass seed/seedling transplantation is highly regarded due to less destructive of donor seagrass meadows and enhancement of genetic diversity in the restoration seagrass meadows. The sediment type in the planting area is an important factor in determining the rates of seed/seedling transplantation success. However, there is little information of tropical seagrass seed germination and seedling growth responding to the sediment type. To address this gap, we carried out a laboratory incubation experiment using different sediment type (fine sand and coarsegravel sand treatments) for seed germination and seedling growth of tropical seagrass Enhalus acoroides. The result shows that the germination rate and mean time-to-germinate were not significant difference between the fine sand and coarse-gravel sand groups, with the mean values of 96.3% and 3.6 days, and 95.0% and 3.4 days, respectively. The survival rate of germinated E. acoroides seedlings in the fine sand was 97.37%, while it was only 81.58% in the coarsegravel sand group. In addition, the E. acoroides seedling leaf and root lengths and their growth rates were all significantly longer and higher in the fine sand group than the coarse-gravel sand group, respectively. Therefore, the impacts of sediment type on E. acoroides seed germination and time-to-germinate are not significant though coarse-gravel sand has much lower seedling survival rate and seedling growth rate. These results indicates that the fine sand sediment type for E. acoroides seed/seedling transplantation in the tropical seagrass restoration should be chosen as it can promote the seed/seedling transplantation success rate. |
| Key words: marine biology Enhalus acoroides sediment type seed germination seedling |
