Diversity of photosynthetic picoeukaryotes in a subtropical neritic ecosystem of the northwestern Pacific – the diel variation of abundance and species composition

View Statistics Email Alert RSS Feed

Information

Details

Project title

Code/計畫編號

MOST105-2313-B019-004

Translated Name/計畫中文名

西北太平洋副熱帶沿岸生態系超微真核藻類多樣性研究-數量與組成日周變化

Project Coordinator/計畫主持人

Kuo-Ping Chiang

Funding Organization/主管機關

National Science and Technology Council

Department/Unit

Institute of Marine Environment and Ecology

Website

https://www.grb.gov.tw/search/planDetail?id=12450233

Year

2016

Start date/計畫起

01-08-2016

Expected Completion/計畫迄

01-07-2017

Bugetid/研究經費

900千元

ResearchField/研究領域

漁業

超微真核藻類(cell size < 3 μm)的多樣性相當高，包含有綠藻 (Chlorophyte)、著鞭毛藻 (Haptophyte) 與隱藻 (Cryptophyte)等，是海洋中重要的基礎生產者。先前的研究指出超微真核藻類的數量有日夜變化，但目前對於造成日夜變動的種類為何並不清楚。本研究利用色素分析(< 20 μm)、18S DNA 定序與螢光原位雜合法與來研究台灣東北沿岸超微真核藻類數量日夜變化與其種類組成。研究結果顯示，色素分析中綠藻的特徵色素 chlorophyll b (Chl b) 濃度有日夜周期變化並且 Chl b 濃度與超微真核藻類數量有正相關，代表含 Chl b 之物種可能是超微真核藻類的重要貢獻者。18S rDNA 定序結果顯示，白天與晚上的種類組成大不相同，白天時段大多以矽藻為主，晚上時段，Mamiellophyceae (綠藻門) 的比例會大幅增加，包含有 Micromonas 和 Ostreococcus。螢光原位雜合法結果顯示 Mamiellophyceae 平均佔超微真核藻類數量的 90% 以上。七月與八月以 Micromonas 為主，而九月以 Ostreococcus 為主。以上的結果顯示超微真核藻類數量的日夜變化主要是由 Mamiellophyceae 所造成，代表他們對於沿岸生態系中的碳循環佔有重要地位，未來可進一步對優勢族群進行能量傳遞之評估。 Photosynthetic picoeukaryotes (PPEs, < 3μm) are highly diverse, comprising chlorophytes, haptophytes and cryptophytes, and so on. Also, they are abundant in the ocean, playing an important role as primary producers in the ocean. Previous studies have pointed out that a diel variation of picoeukaryotes abundance existed, but little is known about what PPEs were responsible for diel variation. In this study, we try to understand the diel variation of PPEs regarding to their abundance and community in the northeastern coastal water of Taiwan based on the High-Performance Liquid Chromatography (HPLC), 18S rDNA clone libraries and Tyramide Signal Amplification - Fluorescent In Situ Hybridization (TSA-FISH). The HPLC results showed that there is a diel variation on Chl b concentrations which was correlated with PPE abundances, implying that Chl b concentrations were mainly contributed by PPEs. The result of 18S rDNA clone libraries showed that PPE community composition was distinct between day and night, and diatom sequence was dominant in daytime. At night, Mamiellophyceae sequences containing Micromonas and Ostreococcus. The results of TSA-FISH showed that Mamiellophyceae (Chlorophyta) accounted for > 90% of PPE abundance. In Mamiellophyceae, Micromonas was dominant in July and August while Ostreococcus was dominant in September. The above results showed that the diel variation of PPE abundance was caused by the Mamiellophyceae implying their importance on carbon cycles in a coastal ecosystem. In the future, energy flow in dominant population is worth to evaluate.

DSpace CRIS

Diversity of photosynthetic picoeukaryotes in a subtropical neritic ecosystem of the northwestern Pacific – the diel variation of abundance and species composition

Details

Description