| 摘要: |
| 过去几十年，中国近海有害藻华的发生频率、规模和面积不断增大, 对我国水产养殖业、渔业和近岸生态系统造成了重大损失和威胁。 在引起有害藻华的众多原因中，藻华甲藻的特殊生活史策略，尤其是形成休眠孢囊，提供了一种关键的机理，因为孢囊的形成过程常伴随着基因重组从而增加了藻华藻的生态适应性；孢囊厚的囊壁增加了其对不利环境条件的耐受性；厚的囊壁使其免于病原体感染和捕食攻击；孢囊的适时萌发为藻华提供了“种源”；孢囊可通过自然或人为原因如船舶压舱水传播从而扩大了其地理分布。我们综述并讨论了甲藻生活史和孢囊研究的如下几个重要方面：１）甲藻生活史的复杂性和有关甲藻孢囊概念及归类的争议；２）沉积物中孢囊“作图（cyst mapping）”在藻华模型和预测（报）中的重要性以及孢囊分布/丰度与藻华规模耦合关系的复杂性和条件依赖性；３）孢囊形成和萌发的若干影响因子及其复杂性和可变性；和４）最近些年来分子生物学技术和各种组学手段在甲藻生活史和孢囊研究中的部分应用，特别是植物激素在孢囊形成、萌发过程中的可能作用。在简要评述了国际、国内有关研究历史中的路标性成果后，最后强调了四个值得重视的研究方向。 |
| 关键词: 有害藻华 甲藻 生活史 休眠孢囊 孢囊形成 孢囊萌发 压舱水 沉积物 |
| DOI：10.12036/hykxjk20160730001 |
| 分类号: |
| 基金项目:国家自然科学基金项目（面上项目，重点项目，联合基金项目，青年基金项目） |
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| Characteristical Life History (Resting cyst) Provides a Mechanism for Recurrence and Geographic Expansion of Harmful Algal Blooms of Dinoflagellates: A Review |
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Tang Ying Zhong,Hu Zhang Xi and Deng Yun Yan
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Institute of Oceanology, Chinese Academy of Sciences,Institute of Oceanology, Chinese Academy of Sciences,Institute of Oceanology, Chinese Academy of Sciences
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| Abstract: |
| The coastal waters of China Seas have observed many harmful algal blooms (HABs) caused by dinoflagellates such as Karenia mikimotoi, Prorocentrum donghaiense, Karlodinium veneficum, and Cochlodinium polykrikoides in the last decades and the associated catastrophic losses in shellfish aquaculture, fisheries and coastal ecosystems. In the view of addressing these problems, we revew the advancements in our knowledge about the characteristical life history and in particular, resting cysts, of dinoflagellates, because cysts have been shown to be associated with genetic recombination; resistance to unfavorable environmental conditions; protection from viruses, grazers, or parasite attacks；termination of algal blooms；seeding recurrent HABs; and geographic expansion of populations via ships'' ballast water, which, together, proves that resting cyst plays a central role in the ecology of HABs caused by dinoflagellates. We reviewed and discussed 1) the complexity of life cycles of dinoflagellates and controversies in the definitions and categorization of cysts, 2) the importance of cyst mapping in sediments in forcasting blooms and the associated complexity in the coupling between cyst abundance/distribution and the magnitude of blooms, 3) the complexity of factors affecting encystment and excystment, and 4) the recent progresses in genomic and transcriptomic studies on dinoflagellates in general and cyst-relevant molecular mechanisms in particular, and the possible vital roles of phytohormone in cyst-relevant processes. After a brief summary of the landmarks along cyst-relevant studies in the international HAB community and China, we end the revew by highlighting four research themes about the life history and cyst-relevant issues in China, namely, 1) more comprehensive investigations on an inventory of dinoflagellate cysts in the coastal sediments of China Seas and on the life histories of those important HAB species in China, 2) more intensive investigations on the species of cysts carried in those ships arriving ports of China and assessments of possible bioinvasion of alien HAB species via ships'' ballast water, 3) more field investigations on the processes in encystment, excystment, and coupling between life history events and bloom dynamics, and 4) investigations on the molecular processes relevant to encystment, dormancy, and excystment via a combined approach of -omics and physiology, as well as applications of different molecular probes for detecting HAB species and particular types of cells pertinent to bloom dynamics. |
| Key words: Harmful algal blooms Dinoflagellates Life history Resting cysts Encystment Excystment Ships'' ballast water Sediment |
