以三峡水库长江干流库区超微型真核浮游生物为研究对象,在三峡水库干流库区设置2个采样点(CJ01,CJ05),分别在2015春季(4月)、夏季(8月)、秋季(10月)和冬季(12月)进行季度采样;采用Illumina Miseq PE250高通量测序平台对8个样本的18S r ...以三峡水库长江干流库区超微型真核浮游生物为研究对象,在三峡水库干流库区设置2个采样点(CJ01,CJ05),分别在2015春季(4月)、夏季(8月)、秋季(10月)和冬季(12月)进行季度采样;采用Illumina Miseq PE250高通量测序平台对8个样本的18S r DNA进行测序。结果显示,三峡水库长江干流库区超微型真核浮游生物群落主要的类群有隐藻、纤毛虫以及领鞭毛虫等,此外还有大量未分类物种。群落结构存在时空演化,其时空演化以时间为主。三峡水库长江干流库区群落物种丰富度和多样性从春季开始逐渐增加,到冬季后开始降低。水体温度(WT)、化学需氧量(COD)与春季群落成正相关,与秋季群落成负相关。总磷(TP)、磷酸盐(P-PO4)、溶解氧(DO)、氧化还原电位(ORP)与秋季群落成正相关,与春夏季群落成负相关。展开更多
Responses of Prochlorococcus (Pro), Synechococcus (Syn), pico-eukaryotes (Euk) and heterotrophic bacteria (Bact) in pelagic marine ecosystems to external nutrient perturbations were examined using nitrogen- (N), phosp...Responses of Prochlorococcus (Pro), Synechococcus (Syn), pico-eukaryotes (Euk) and heterotrophic bacteria (Bact) in pelagic marine ecosystems to external nutrient perturbations were examined using nitrogen- (N), phosphorus- (P), iron- (Fe), and cobalt- (Co) enriched incubations in the South China Sea in November 1997. Variations in abundance of the 4 groups of microorganism and cellular pigment content of the autotrophs during incubation were followed by flow-cytometric measurements for seven days. During the incubation, Syn and Euk showed a relatively higher demand on Fe and N, while Pro required higher levels of Co and P. The Fe was inadequate for all the organisms in the deep euphotic zone (75 m) of the study area. The experimental results also implied that biological interaction among the organisms played a role in the community structure shift during the incubation. It seemed that besides the effects of temperature, there are some other physical and chemical limitations as well as impacts from biological interactions on Pro distribution in coast waters.展开更多
Abstract Picoplankton distribution was investigated in different water masses of the East China Sea in November, 2006 and February, 2007. The autumn and winter cruises crossed three major water masses： the coastal wa...Abstract Picoplankton distribution was investigated in different water masses of the East China Sea in November, 2006 and February, 2007. The autumn and winter cruises crossed three major water masses： the coastal water mass （CWM）, the mixed water mass （MWM）, which forms on the continental shelf, and the Kuroshio water mass （KWM）. Picoplankton composition was resolved into four main groups by flow cytometry, namely Synechococcus, Prochlorococcus, picoeukaryotes, and heterotrophic bacteria. The average abundances of Synechococcus, picoeukaryotes, and heterotrophic bacteria were （0.63＋ 10.88）~ 103, （1.61＋1.16）x103, （3.39~1.27）x105 cells/mL in autumn and （6.45~8.60）x103, （3.23~2.63）x103, （3.76~1.37）x 105 cells/mL in winter, respectively. Prochlorococcus was not found in the CWM and seldom observed in surface samples in either season. However, Prochlorococcus was observed in the MWM and KWM （approximately 103 cells/mL） in both auttman and winter. Synechococcus distribution varied considerably among water masses, with the highest levels in KWM and lowest levels in CWM. The depth-averaged integrated abundance of Synechococcus was approximately 5-fold higher in KWM than in CWM, which may be due primarily to water temperature. In the MWM, Synechococcus was resolved as two subgroups; the presence of both subgroups was more common in autumn. Picoeukaryote abundance varied less among water masses than Synechococcus, and heterotrophic bacteria depth-averaged integrated abundance exhibited the smallest seasonal variations with respect to water mass. Correlation analysis showed that relationships between picoplankton abundances and environmental factors （temperature, nutrients, and chlorophyll a） differed among the three water masses, suggesting that the three water masses have different effects on picoplankton distribution （particularly Synechococcus）.展开更多
文摘以三峡水库长江干流库区超微型真核浮游生物为研究对象,在三峡水库干流库区设置2个采样点(CJ01,CJ05),分别在2015春季(4月)、夏季(8月)、秋季(10月)和冬季(12月)进行季度采样;采用Illumina Miseq PE250高通量测序平台对8个样本的18S r DNA进行测序。结果显示,三峡水库长江干流库区超微型真核浮游生物群落主要的类群有隐藻、纤毛虫以及领鞭毛虫等,此外还有大量未分类物种。群落结构存在时空演化,其时空演化以时间为主。三峡水库长江干流库区群落物种丰富度和多样性从春季开始逐渐增加,到冬季后开始降低。水体温度(WT)、化学需氧量(COD)与春季群落成正相关,与秋季群落成负相关。总磷(TP)、磷酸盐(P-PO4)、溶解氧(DO)、氧化还原电位(ORP)与秋季群落成正相关,与春夏季群落成负相关。
文摘Responses of Prochlorococcus (Pro), Synechococcus (Syn), pico-eukaryotes (Euk) and heterotrophic bacteria (Bact) in pelagic marine ecosystems to external nutrient perturbations were examined using nitrogen- (N), phosphorus- (P), iron- (Fe), and cobalt- (Co) enriched incubations in the South China Sea in November 1997. Variations in abundance of the 4 groups of microorganism and cellular pigment content of the autotrophs during incubation were followed by flow-cytometric measurements for seven days. During the incubation, Syn and Euk showed a relatively higher demand on Fe and N, while Pro required higher levels of Co and P. The Fe was inadequate for all the organisms in the deep euphotic zone (75 m) of the study area. The experimental results also implied that biological interaction among the organisms played a role in the community structure shift during the incubation. It seemed that besides the effects of temperature, there are some other physical and chemical limitations as well as impacts from biological interactions on Pro distribution in coast waters.
基金Supported by the National Basic Research Program of China(973 Program)(No.2011CB409804)the National Natural Science Foundation of China for Creative Research Groups(No.41121064)the Knowledge Innovation Program of China(No.KZCX2-YW-Q07-02)
文摘Abstract Picoplankton distribution was investigated in different water masses of the East China Sea in November, 2006 and February, 2007. The autumn and winter cruises crossed three major water masses： the coastal water mass （CWM）, the mixed water mass （MWM）, which forms on the continental shelf, and the Kuroshio water mass （KWM）. Picoplankton composition was resolved into four main groups by flow cytometry, namely Synechococcus, Prochlorococcus, picoeukaryotes, and heterotrophic bacteria. The average abundances of Synechococcus, picoeukaryotes, and heterotrophic bacteria were （0.63＋ 10.88）~ 103, （1.61＋1.16）x103, （3.39~1.27）x105 cells/mL in autumn and （6.45~8.60）x103, （3.23~2.63）x103, （3.76~1.37）x 105 cells/mL in winter, respectively. Prochlorococcus was not found in the CWM and seldom observed in surface samples in either season. However, Prochlorococcus was observed in the MWM and KWM （approximately 103 cells/mL） in both auttman and winter. Synechococcus distribution varied considerably among water masses, with the highest levels in KWM and lowest levels in CWM. The depth-averaged integrated abundance of Synechococcus was approximately 5-fold higher in KWM than in CWM, which may be due primarily to water temperature. In the MWM, Synechococcus was resolved as two subgroups; the presence of both subgroups was more common in autumn. Picoeukaryote abundance varied less among water masses than Synechococcus, and heterotrophic bacteria depth-averaged integrated abundance exhibited the smallest seasonal variations with respect to water mass. Correlation analysis showed that relationships between picoplankton abundances and environmental factors （temperature, nutrients, and chlorophyll a） differed among the three water masses, suggesting that the three water masses have different effects on picoplankton distribution （particularly Synechococcus）.
