蚯蚓(Eiseniafetida)细胞色素P450及抗氧化酶系对环境浓度苯并(a)芘的响应

以赤子爱胜蚓(Eisenia fetida)为供试生物,草甸棕壤为供试土壤,以蚯蚓微粒体细胞色素P450含量、抗氧化酶系以及谷胱甘肽转移酶活性为指标,进行了土壤中苯并(a)芘[B(a)P]暴露与酶活性的量-效关系研究。结果表明,在接近沈抚灌区实地污染状况B(a)P(0.1～2.0mg.kg-1)暴露下,第1、3、7以及第14d取样时,P450和SOD有较好的响应:SOD在第1、3d显著升高,而在第7、14d时降低;P450总体表现为低浓度B(a)P���导下降低,高浓度下升高的趋势。CAT、POD以及GST的敏感性相对较差。比照其他4个指标,蚯蚓P450的敏感性更为优异,具有较好的应用前景。指标敏感性总体表现为:P450>SOD>CAT/POD>GST。

污染土壤中苯并(a)芘的微生物降解

本文以B(a)P���染土壤为处理对象 ,进行了土壤微生物群体及单一菌对B(a)P���降解试验 ,结果表明 ,鲜土中的微生物降解力 >风干土的微生物降解力。土壤微生物群体比单一微生物降解B(a)P���果好。真菌的降解能力强于细菌。 2 2 0 9号镰刀菌降解B(a)P���速率最快 ,为高效降解菌

Thermodynamical study on pressure-induced compatibility in UCST polymer-containing mixtures

The present calculations were performed on the basis of the Sanchez-Lacombe lattice fluid theory and the new combinatorial rules for block copolymer according to the experimental results on the pressure-induced compatibility in poly(ethylene oxide) (PEO) and poly(ethylene oxide-b-dimethylsiloxane) (P(EO-b-DMS)) mixtures with UCST behavior. The study on enthalpy, combinatorial entropy, vacancy entropy and Gibbs energy upon mixture shows that Sanchez-Lacombe fluid theory and the new combinatorial rules could describe the pressure-induced compatibility (PIC) of polymer mixtures with UCST behavior well.

有机硅及其改性聚合物膜用于有机溶剂水溶液的渗透汽化分离

采用室温固化硅橡胶及其它三种改性硅氧烷聚合物制成渗透汽化膜,分离丙酮(A),丁酮(B)、乙醇(E)及异丙醇(P)等有机物的水溶液。结果表明,随着透过温度提高、透量成指数关系增大,但对分离系数影响甚小。透量大小顺序为A>B>E>P,分离系数大小顺序为A>B>P>E,当膜材料中(CH_3)_2SiO链节含量由70%上升到100%时,有机物的透量及分离系数同时增加。

牙鲆和大黄鱼经济性状候选基因的DNA���子标记研究

本文利用不同的分子标记方法，分别对牙鲆及大黄鱼不同养殖群体的生长、抗病等经济性状的候选基因进行了序列多态性研究，检测到了几个SNP���点和微卫星的多态性位点，并分析了它们与经济性状之间的相关性；同时，利用微卫星的多态性位点对牙鲆2个养殖群体的遗传变异进行了分析，这些均为海水鱼类遗传育种及标记辅助选育工作提供了基础数据。 在牙鲆胶南养殖群体中，以100个个体为实验材料，根据其生长激素（GH）基因的6个外显子序列设计引物，通过SSCP���析技术显示该群体GH基因的第4外显子存在多态性，检测到2种基因型，AA型和AB型。DNA���序结果表明，AB型在第1763位发生碱基突变，c→t，与AA型同源性达到99%。连锁分析结果表明：这2种基因型的个体在体重和头长上表现出显著的差异，AB型个体的体重和头长都明显大于AA型个体(P<0.05)，由此推测等位基因B是一个对牙鲆体重和头长都有利的等位基因；这2种基因型个体之间在其体型性状上也存在显著差异（P<0.05）；同时，该多态位点的Hardy-Weinberg平衡性检验结果表明，该群体处于Hardy-Weinberg平衡状态。在牙鲆GH基因第1外显子区域还发现了一个微卫星位点，对该位点进行多态性分析，检测到5种基因型、3种等位基因，one-way ANOVA���计结果显示，基因型AC个体的体重、头长和体高明显大于其它基因型个体（P<0.05），C是一个对体重、头长和体高有利的等位基因。 对2个大黄鱼养殖群体的GH基因进行SSCP���析后发现，浙江群体大黄鱼GH基因在第196位存在1个SNP���g→a���位点，检测到2种基因型，AA和AB。t检验结果表明，AA型个体的体高比AB型个体的高(P���0.05)，但AB型个体在体长/体高上占优势(P���0.05)，提示该突变位点可以作为大黄鱼体型性状的候选标记。福建群体大黄鱼GH基因在第692位有1个SNP���点(t→c)，共检测到2种基因型，CC型和CD型，其中，CD基因型个体的体重和全长显著大于CC基因型个体(P���0.01)，提示该位点可以作为大黄鱼体重和头长性状的候选标记。 在牙鲆胶南和日照2个养殖群体中，采用牙鲆GHR基因5’端Promoter区的一个微卫星标记，进行了群体遗传变异的研究，并探索了该基因多态性位点与牙鲆生长性状之间的相关性。结果表明，2个群体在该位点检测到的等位基因数为12和9个，有效等位基因数为6.26和5.04个。两个群体该位点的Hardy-Weinberg遗传偏离指数均为正值，并没有显示出杂合子缺失，但各基因型分布频率都在一定程度上偏离Hardy-Weinberg平衡(P<0.01)。连锁分析发现，在胶南群体中，IM基因型对应的个体在全重、全长、体长、头长、体高和眼径形态学数据中均是最大的，但仅在体重上极其显著的大于全部其它基因型个体；在日照群体中，BC基因型对应的个体在全重、全长、体高、尾柄高、尾柄长和眼径数据中均是最大的；而CJ基因型对应的个体在体长和头长这两组数据中是最大的。由此认为，该位点IM基因型可以作为牙鲆体重性状的潜在标记。 在进行牙鲆抗病性状标记的筛选时，利用迟缓爱德华氏菌（Edwardsiella tarda���LSE40对牙鲆鱼进行攻毒感染实验，得到死亡群体和未死亡群体。选择Toll样受体基因中的TLR2、TLR3和TLR9基因作为候选基因，分别对这3个基因中的部分序列共设计7对引物进行扩增，同时对扩增产物进行RFLP���态性分析，目前只在TLR3基因内检测到一个EcoRI的酶切多态性位点，测序后发现，这是由于在TLR3基因第3806位的EcoRI酶切位点在某些个体中缺失所致。酶切产物共呈现出3种基因型，分别定义为AA，AB和BB。χ2检验证明该多态性位点与牙鲆抗迟缓爱德华氏菌LSE40的能力有一定关系。利用多因素非条件Logistic回归分析对死亡组和存活组牙鲆的各种形态学数据以及不同基因型之间进行了分析，发现体长、头长和体高均具有显著的相关性（P<0.05），而这几个因素与体重的相关性不显著（P>0.05）。多因素非条件Logistic分析后发现：AA基因型对死亡率具有显著的影响（P<0.05），是主要的危险因素，而AB基因型的作用不显著（P>0.05）；头长是主要的保护因素（P<0.05），体重对死亡率的影响很小。χ2检验证明，等位基因A���对死亡的主要危险等位基因，B是对存活有利的主要等位基因。推测该位点可以作为牙鲆抗迟缓爱德华氏菌的潜在标记。

The combined effects of temperature and food supply on Calanus sinicus in the southern Yellow Sea in summer

The effects of temperature and food availability on the life history strategy of the planktonic copepod Calanus sinicus in the southern Yellow Sea in summer were studied in this paper. The fifth copepodite stage (CV) dominates the population in the central part of the southern Yellow Sea, where the Yellow Sea Cold Water Mass (YSCWM) occurs below the thermocline. Incubation experiments were conducted on CV C. sinicus caught from the YSCWM to examine the effects of temperature and food availability. Temperature at the surface (27degreesC) is lethal to CVs regardless of food availability. At the temperature in the middle of the thermocline (18degreesC), survival time of the specimens depends on food availability, being similar to20 days in treatments without extra food supply. At the temperature in the YSCWM (9degreesC), most animals survive at the end of 27 day incubation even in treatments without food supply. Developmental rate of CVs at 9degreesC without extra food supply is extremely low. The increase of either temperature or food supply promotes the developmental rate of CVs. According to these results, the surface layers with high temperature and low food abundance are detrimental for the survival and reproduction of C. sinicus. Low temperature and low food availability in the YSCWM help CV to maintain a much lower developmental rate and higher survival rate. The ecological trait of C. sinicus in the southern Yellow Sea in summer cannot be sufficiently explained solely by the effects of temperature.

Abundance of Calanus sinicus across the tidal front in the Yellow Sea, China

The abundance of Calanus sinicus eggs, nauplii, copepodites and adults and chlorophyll a (Chl-a) concentration were studied across tidal fronts in October 2000, and May and June 2001 in the Yellow Sea, China. The aim of the study was to evaluate the role of tidal fronts in the ecology of C. sinicus. The hydrographic tidal fronts were identified by the horizontal temperature gradient in the bottom layer and the temperature profiles across the fronts. The survey results showed that the concentration of Chl-a was high in the vicinity of the fronts, particularly in spring and early summer. The abundance of C. sinicus eggs and nauplii was usually higher in the tidal fronts than in the adjacent areas. In May and June 2001, the abundance of copepodites and adults of C. sinicus peaked in the tidal front. In June 2001 and October 2000, many copepodites and adults were found in stratified region.

Response of integrated biomarkers of fish (Lateolabrax japonicus) exposed to benzo[a]pyrene and sodium dodecylbenzene sulfonate

Fish Lateolabrax japonicus were exposed to 0.1 and 1 mg/L of anion surfactant sodium dodecylbenzene sulfonate (SDBS) and to 2 and 20 mu g/L of benzo[a]pyrene (B[a]P) for 6, 12, and 18 days, with control and solvent control groups. Liver antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH), and glutathione S-transferase (GST), were determined; brain acetyleholinesterase (AChE) and liver inducible nitric oxide synthase (iNOS) activities were also measured. The results indicated that (1) L. japonicus avoided oxidative damage through antioxidant systems; (2) SOD, GPx, and GSH were induced, and GST was inhibited and then induced by B[a]P exposure; and (3) CAT, GPx, and AChE were induced while NOS was inhibited, and GST was induced and then inhibited by SDBS stress in experimental period. (c) 2005 Elsevier Inc. All rights reserved.

Competition between Stipa grandis and Cleistogenes squarrosa

Competitive strategy for resources between Cleistogenes squarrosa (Trin.) Keng which is a dominant species of grasslands degraded by moderate-heavy grazing, and Stipa grandis P. Smirnov, which is a dominant species of ungrazed communities, was studied using a replacement series method in a greenhouse. The knowledge would be helpful in managing grasslands and restoring the degraded C. squarrosa grassland. Although there was neither inter- nor intra-specific competition between the two species when no nutrients were added, intra-specific competition of C. squarrosa was observed and increased with increased nutrient availability and more sulfur (S) was allocated to the aboveground partition of the plant. Relative competitive ability of C. squarrosa was greater than that of S. grandis when nutrients were supplied regardless of S. There was no significant difference between shoot and root competition based on dry matter yields. However, root competition was significantly greater than that of shoot based on S uptake under all treatments. A significant interaction was not observed between shoot and root competition. Therefore, nutrients addition benefits the restoration of degraded grassland of C. squarrosa, which may not exclude S. grandis. Also productivity and forage quality of the community will be increased. (C) 2007 Elsevier Ltd. All rights reserved.

Responses of Artemisia frigida Willd. (Compositae) and Leymus chinensis (Trin.) Tzvel. (Poaceae) to sheep saliva

Although studies show that grazing and browsing by herbivores have marked effects on host plants, the mechanisms remain unclear. The objective of this study is to determine the effects of sheep saliva on host plant growth. Sheep saliva was manually applied to clipped plants of two different life forms, a semi-shrub, Artemisia frigida Willd., and a herbaceous species, Leymus chinensis (Trin.) Tzevel. The results showed that sheep saliva significantly enhanced aboveground net primary productivity (ANPP) and the ratio of ANPP to belowground net primary productivity (BNPP) for both species. This indicated that sheep saliva promotes aboveground compensatory growth and allocation of photosynthate to aboveground for both plant species. Sheep saliva stimulated only tillering of L. chinensis. Regardless of saliva application, clipping significantly decreased BNPP and plant height, but significantly increased the number of branches or tillers for both plant species. The relative growth rates (RGRs) on both species were significantly greater after clipping with saliva compared with control and clipping without saliva treatments. In addition, RGR of the herbaceous species L. chinensis was faster than that of the semi-shrub A. frigida after application of saliva. (c) 2006 Elsevier Ltd. All rights reserved.