沉水植物对重金属的吸收净化和受害机理研究进展

沉水植物对重金属的积累净化和受害机理研究主要集中在4个方面:(1)沉水植物对重金属(包括放射性物质)的吸收、积累和净化作用;(2)沉水植物对重金属的抗性强弱和机制;(3)沉水植物用于监测水体的重金属污染:(4)沉水植物的重金属胁迫机制,包括重金属对植物形态和显微结构的损伤,对植物抗氧化酶系统的影响,对植物的叶绿素、蛋白质以及光合与呼吸作用等生理生化指标的影响,植物对重金属的吸附和转运动力学,以及Zn对Cd毒害的拮抗等。

处于性腺不同发育阶段斜带石斑鱼垂体的EST表达差异分析

斜带石斑鱼是重要的海产经济鱼类,在其个体发育过程中存在先雌后雄的天然性反转现象。垂体是调节生长和生殖等生理过程的重要内分泌器官。构建了斜带石斑鱼分别处于卵巢发育起始和性反转后期的垂体SMARTcDNA的质粒文库,并通过测序分别筛选到232个和258个表达序列标签(expressed sequence tags,EST)。将所得EST与GenBank数据库中的序列进行比对,结果表明,处于卵巢发育起始和性反转后期斜带石斑鱼垂体EST中,激素所占比例均为最高,分别为40.5%和34.9%。进一步比较分析了这两个

稀有鮈鲫血液学指标的研究

江西省自然科学基金(0130004); 中国科学院知识创新工程重要方向项目(KSCX-SW-125)资助

人工湿地小试系统藻类去除效果的变化研究

夏季在水力负荷为800mm/d间歇式进水条件下,研究了人工湿地不同工艺流程的8套小试系统SSP(sys-temofsmallplot)内部水流方向上藻类去除率的变化。结果表明:人工湿地小试系统中,藻类生物量沿水流方向逐渐减少,除藻率在出水处均达到最大值。藻类的去除主要发生在湿地水流方向的前几层,而系统其他层对藻类只有微弱的去除效果。由下行池与上行池构成的湿地系统中,去藻是上、下行池共同作用的结果。在有推流床或塘处理系统参与的湿地系统中,它们对藻类的去除均有一定的作用。去藻作用主要是基质的拦截,不同的水流方

以RAPD方法分析岩原鲤分类地位

采用opaopoopq等系列44个随机引物对鲤亚科与亚科的几个种类进行随机扩增多态DNA(RAPD)扩增,通过对电泳结果进行系统分析,得出各种间遗传距离分支图.按节点的遗传距离最大数值0.232可以分出亲缘关系最远的两个群体,即由两种普通鲤为一群体,以及由岩原鲤、倒刺和白甲鱼组成的另一群体.从节点间遗传距离数值叠加计算可以得出岩原鲤与其他各种鱼类亲缘关系,遗传距离由近到远分别是:岩原鲤与倒刺(0.344)<岩原鲤与白甲鱼(0.388)<岩原鲤与普通鲤(0.443),岩原鲤与倒刺的遗传距离最小,这一

快速建立鲢、鳙纯系的初步研究

运用随机扩增多态性DNA(RAPD)方法对雌核发育和人工转性鲢、鳙进行了遗传多样性的研究,并用长江天然鲢、鳙群体作为对照分析.在雌核发育鲢中,共得到187条带,其中19条为多态带,占10.16％,而对照组鲢共扩增205条带,有32个多态座位,占总带数的15.61％.在雌核发育鳙中共产生232条带,其中11条为多态带,比例为4.74％,而在对照组中共产生241条带,25条为多态带,比例为10.37％.遗传距离分析表明,雌核发育鲢和鳙的平均值分别为0.102和0.023.而对照组鲢和鳙遗传距离平均值分别为0.

沉水植物分布格局对湖泊水环境N、P因子影响

利用实地调查数据模拟保安湖沉水植物分布及水环境生态因子场。应用GIS空间分析功能 ,分别空间选取四种优势沉水植物 (金鱼藻CeratophyllumdemersumL .,穗状狐尾藻MyriophyllumspicatumL .,微齿眼子菜PotamogetonmaackianusA .Benn .,及苦草VallisneriaspiralisL .)的分布水域及无沉水植物分布水域的局部生态因子场。根据得到的局部因子场特征 ,比较分析不同水生植物分布格局对水环境中N、P因子的影响。结果显示四种沉水植物的分

珞珈山森林土壤原生动物生态学研究及土壤原生动物定量方法探讨

１９９３年１月至１２月，用直接计数法和培养计数法对武昌珞珈山森林土壤原生动物进行了周年定量研究，发现原生动物丰度的周年动态趋势为：春季（３—５月）达到高峰，低谷出现在冬季（１—２月），夏秋季保持较平稳的变动。原生动物丰度与土壤环境因子间的相关性分析结果表明，原生动物丰度的周年动态与土壤含水量及土壤ｐＨ值的变化呈显著的正相关，与土壤温度的变化无明显相关关系。珞珈山森林土壤原生动物优势种为梨波豆虫（Ｂｏｄｏｅｄａｘ）、球波豆虫（Ｂｏｄｏｇｌｏｂｏｓｕｓ）、卵形隐滴虫（Ｃｒｙｐｔｏｍｏｎａｓｏｖａｔａ）、长尾尾

新型浮选剂MPA对鱼类毒性效应的研究

MPA是一种新型浮选剂,主要由29种醇类化合物组成。测得它的96h的LC_(50)值:草鱼胚胎为100—200mg/L;草鱼苗为75.86mg/L;草鱼种为122.77mg/L。引起草鱼胚胎弯体畸形的EC_(50)值为48.98mg/L。弯体不严重的鱼苗在清水中饲养,能恢复成正常的鱼苗。对鱼苗生长没有影响的浓度是6.65mg/L。浓度为100mg/L的MPA在水环境中一周能去除一半,20天后未检出,在该浓度内放入的草鱼种,对其生长没有明显的影响。

温度对萼花臂尾轮虫卵的发育、种群增长和生产量的影响

1981—1983年,在不同的培养温度下,观察了萼花臂尾轮虫(Brachionus calyciflorus)卵的发育时间、种群的增长并用3种不同方法测算生产量。在5—30℃的培养温度下,轮虫卵的发育时间(D)随温度(T)升高而缩短,其曲线迴归方程为: LnD=2.0539+0.1097LnT-0.3046(LnT)~2 在10,15,20,25℃的培养温度下,从休眠卵孵化出来的孤雌生殖雌体,其繁殖的种群增长曲线都呈“S”形,或称逻辑斯蒂曲线(Logistic curve)。不同的温度,种群达到高峰所需的

The youngest split in sympatric schizothoracine fish (Cyprinidae) is shaped by ecological adaptations in a Tibetan Plateau glacier lake

Although new empirical evidence shows that sympatric speciation has occurred in some species, there are few indisputable model organisms for this process of speciation. The two subspecies (Gymnocypris eckloni eckloni and G. e. scoliostomus) of the schizothoracine Gymnocypris fish species complex from a small glacier lake in the Tibetan Plateau, Lake Sunmcuo, fit several of the key characteristics of the sympatric speciation model. We used combined mitochondrial control region sequences and the cytochrome b gene (1894 bp) to address the phylogenetics and population genetics of 232 specimens of G. e. eckloni and G. e. scoliostomus, as well as all of its closely related sister species. We found that: (i) a total of four old lineages were uncovered in the widespread G. e. eckloni, of which only one was shown to be shared with all G. e. scoliostomus individuals and (ii) the new subspecies (G. e. scoliostomus) evolved in Lake Sunmcuo from the ancestral G. e. eckloni population within approximately 0.057 Ma. These two taxa of the species complex are morphologically distinct, and reproductive isolation is further suggested. Ecological disruptive selection based on morphological traits (e.g. mouth cleft characters) and food utilization may be a mechanism of incipient speciation of two sympatric populations within Lake Sunmcuo. This study provides the first genetic evidence for sympatric speciation in the schizothoracine fish.

How polluted is the Yangtze River? Water quality downstream from the Three Gorges Dam

The concentrations of major anions and cations, nitrogen and phosphorus, dissolved and particulate trace elements, and organic pollutants were determined for the middle and lower reaches of the Yangtze River (Changjiang) from below the Three Gorges Dam (TGD) to the mouth at Shanghai in November 2006. The concentration of dissolved inorganic phosphate (DIP) was constant at a low level of 6-8 mu gP/L, but the concentration of nitrate (NO3-) approximately doubled downstream and was closely correlated with K+. This translated to a daily load of well over 1000 It of dissolved inorganic nitrogen (DIN) at Datong. The average concentrations of dissolved Pb (0.078 +/- 0.023 mu g/L), Cd (0.024 +/- 0.009 mu g/L), Cr(0.57 +/- 0.09 mu g/L), Cu (1.9 +/- 0.7 mu g/L), and Ni (0.50 +/- 0.49 mu g/L) were comparable with those in other major world rivers, while As (3.3 +/- 1.3 mu g/L) and Zn (1.5 +/- 0.6 mu g/L) were higher by factors of 5.5 and 2.5, respectively. The trace element contents of suspended particles of As (31 +/- 28 mu g/g), Pb (83 +/- 34 mu g/g), and Ni (52 +/- 16 mu g/g) were close to maximum concentrations recommended for rivers by the European Community (EC). The average concentrations of Cd (2.6 +/- 1.6 mu g/g), Cr (185 +/- 102 mu g/g), Cu (115 +/- 106 mu g/g), and Zn (500 +/- 300 mu g/g) exceeded the EC standards by a factor of two, and Hg (4.4 +/- 4.7 mu g/g) by a factor of 4 to 5. Locally occurring peak concentrations exceed these values up to fourfold, among them the notorious elements As, Hg, and Tl. All dissolved and particulate trace element concentrations were higher than estimates made twenty years ago [Zhang, J., Geochemistry of trace metals from Chinese river/estuary systems: an overview. Estuar Coast Shelf Sci 1995; 41: 631-658.]. The enormous loads of anthropogenic pollutants disposed to the river were diluted by the large water discharge of the Yangtze even during the lowest flow resulting in the relatively low concentration levels of trace elements and organic pollutants observed. We estimated loads of e.g. As, Pb and Ni to the East China Sea to be about 4600 kg As d(-1), 3000 kg Pb d(-1), and 2000 kg Ni d(-1). About 6000 t d(-1) of dissolved organic carbon (DOC) was delivered into the sea at the time of our cruise. We tested for 236 organic pollutants, and only the most infamous were found to be barely above detection limits. We estimated that the load of chlorinated compounds, aromatic hydrocarbons, phenols, and PAHs were between 500 and 3500 kg d(-1). We also detected eight herbicides entering the estuary with loads of 5-350 kg d(-1). The pollutant load, even when at low concentrations, are considerable and pose an increasing threat to the health of the East China Sea ecosystem. (c) 2008 Elsevier B.V. All rights reserved.

Optimum temperature for the growth performance of juvenile orange-spotted grouper (Epinephelus coioides H.)

Effects of water temperature (17, 21, 25, 30 and 35 degrees C) and body size (14.75-281.41 g initial body weight) on food consumption, growth, feed conversion, and dry matter content in orange-spotted grouper fed to satiation were investigated. The combined effect of temperature (T, degrees C) and body weight (W, g) on maximum food consumption (C-max, g/day) was described as: InCmax= -7.411+0.828 lnW+0.317T-0.004 7T(2), and the optimum feeding temperature was 33.9 degrees C. The combined effect of temperature and body weight on growth (G) was described as: InG= -4.461-0.208lnW+0.394T-0.006 3T(2). The optimum growth temperature was 31.4 degrees C, whereas overall growth rates were high at 25, 30 and 35 degrees C. Feed conversion efficiencies (FCE, %), increasing first and then decreasing with increasing temperature, averaged from 1.8 to 2.1 in terms of dry weight of food fish. The optimum temperature for FCE tended to be lower than that for growth or feeding. Dry matter content increased with both increasing water temperature (17, 25, 30 and 35 degrees C) and body weight, and the combined effect of temperature and body weight on dry matter content (DM, %) was described as: lnDM =3.232+0.01 4 lnW-0.004 4T+0.001 2TlnW.

The innate immune response to grass carp hemorrhagic virus (GCHV) in cultured Carassius auratus blastulae (CAB) cells

Virus infection of mammalian cells activates an innate antiviral immune response characterized by production of interferon (IFN) and the subsequent transcriptional upregulation of IFN-stimulated genes (ISGs) by the JAK-STAT signaling pathway. Here, we report that a fish cell line, crucian carp (Carassius auratus L.) blastulae embryonic (CAB) cells, can produce IFN activity and then form an antiviral state after infection with UV-inactivated grass carp hemorrhagic virus (GCHV), a double-stranded (ds) RNA virus. From UV-inactivated GCHV-infected CAB cells, 15 pivotal genes were cloned and sequenced, and all of them were shown to be involved in IFN antiviral innate immune response. These IFN system genes include the dsRNA signal sensing factor TLR3, IFN, IFN signal transduction factor STAT1, IFN regulatory factor IRF7, putative IFN antiviral effectors Mx1, Mx2, PKR-like, Viperin, IFI56, and other IFN stimulated genes (ISGs) IFI58, ISG15-1, ISG15-2, USP18, Gig1 and Gig2. The identified fish IFN system genes were highly induced by active GCHV, UV-inactivated GCHV, CAB IFN or poly(I).poly(C), and showed similar expression patterns to mammals. The data indicate that an IFN antiviral innate immune response similar to that in mammals exists in the UV-inactivated GCHV-infected CAB cells, and the IFN response contributes to the formation of an antiviral state probably through JAK-STAT signaling pathway. This study provides strong evidence for existence of IFN antiviral innate immune response in fish, and will assist in elucidating the origin and evolution of vertebrate IFN system. (c) 2006 Elsevier Ltd. All rights reserved.

Purification and characterization of hydrosoluble components from the sap of Chinese lacquer tree Rhus vernicifera

Continuous gradient elution chromatography (CGEC) was employed to purify and separate enzymes and polysaccharides from the sap of Rhus vernicifera Chinese lacquer tree. There are three different molecules with laccase enzyme activity. Two are enzymes of each other (L1, and L2), whereas the third (RL) is an entirely separate entity. Two polysaccharides (GP1 and GP2) were also found. The Rhus laccase (RL), and isoenzymes L1 and L2, have peak molecular masses of 109,100, 120,000, 103,000 respectively; each has four copper atoms per molecule, and the pI values were 8.2, 8.6, and 9.1, respectively. The structure of the laccases was studied by Fourier-transform infrared (FT-IR) and Matrix-assisted laser desorption/ionization time-of flight (MALDI-TOF) mass spectrometry. The typical amide I (1646 cm(-1)) and amide II (1545 cm(-1)) bands were observed. The results from MALDI-TOF were similar to those from CGEC, but the molecular mass from the MALDI-TOF was significantly different from that obtained from sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). (c) 2006 Elsevier B.V. All rights reserved.