九龙江西陂库区沉积物甲藻孢囊的分布

孢囊在甲藻的生活史中发挥重要作用,福建省九龙江从2009年起,暴发多次拟多甲藻水华事件。采用显微镜观察和单细胞PCR技术,对九龙江西陂库区2012—2013年不同月份沉积物中的甲藻孢囊进行种属判定,并对甲藻孢囊的分布及其影响因素进行分析。结果表明,西陂库区沉积物中的甲藻孢囊主要为拟多甲藻属,约占80%,其次为裸甲藻属,发现了2009年水华的优势种佩式拟多甲藻(Peridiniopsis penardii)孢囊。库区沉积物中甲藻孢囊的丰度在(13.7±1.2)—(105.2±8.3)个/g干重之间。多元相关分析结果显示甲藻孢囊的丰度与含水率呈现显著正相关性(P0.05),反映了甲藻孢囊沿水流方向逐渐积累。本研究结果填补了国内水库甲藻孢囊鉴定和萌发的研究空白,为九龙江甲藻水华的防治提供科学参考。

Research on the distribution of dinoflagellate cysts in the surface sediments of the XiPi Reservoir in the Jiulong River

Resting cysts play a major role in the life history of dinoflagellates. Peridiniopsis blooms have occurred many times in the Jiulongjiang River (Fujian province) since February 2009. This study investigates the characteristics of dinoflagellate cysts found in the sediments of the Xipi Reservoir in the Jiulongjiang River during different months, from 2012 to 2013. We used microscopy and single-cell Polymerase Chain Reaction (PCR) technology to identify the species of dinoflagellate cysts in a germination experiment. The results show that Peridiniopsis forms the dominant genus among the dinoflagellate cysts found in these sediments, and accounts for 80% of the total population while the rest belong to the genus Gymnodinium. We identified the cysts of Peridiniopsis penardii, the dominant bloom species in 2009. We also assessed the distribution and abundance of dinoflagellate cysts and investigated the driving factors of these population characteristics. The abundances of dinoflagellate cysts in sediments during different months are between (13.7 ± 1.2) to (105.2 ± 8.3) cysts/g DW. The multiple correlation analysis demonstrated that the abundance of dinoflagellate cysts is significantly positively correlated with moisture (P < 0.05). It showed that the distribution of dinoflagellate cysts gradually increased along the direction of the river flow. These results provide new insight into freshwater dinoflagellate cyst characterization and germination in this reservoir, and provide a scientific background for efforts aimed at the prevention of dinoflagellate blooms in the Jiulongjiang River.