鳗鲡气单胞菌引起的烂尾病病原菌抑菌药物的研究

应用药敏纸片法研究了三株烂尾病病原菌（气单胞菌）对３１种药物及不同配合药物的敏感性，测定了４种药物及配合药物ＨＰ对三株菌的最低抑菌浓度（ＭＩＣ）及最低杀菌浓度（ＭＢＣ）。结果表明，配合药物ＨＰ具较强的抑菌能力。     

Characteristics of Vegetation Carbon,Nitrogen, and C/N Ratio in a Tamarix chinensis Coastal Wetland of China

Variations in carbon (C) and nitrogen (N) of the vegetation in a Tamarix chinensis coastal wetland located in Laizhou Bay, China, are analyzed. It is found that T. chinensis accumulates more C and N than the surrounding herbs, and it allocates more C and N in the aboveground parts but less in the roots. Branches store more C, whereas leaves and flowers accumulate more N than other tissues. The C and N contents in the aboveground parts of T. chinensis are mainly influenced by pH, electrical conductivity (EC), water content, and clay content in the top 100 cm of soil as well as the distance from the sea. For the herbs, their C contents vary little in the supratidal zone, but they are higher than those in the intertidal zone. However, N contents in the herbs are higher in the aboveground parts and varied among different communities. The contents of C and N in the herbs are affected by EC, water content as well as the contents of organic C and total nitrogen (TN) in the top 10 cm of soil. The findings confirm that increasing the biomass of T. chinensis is an effective way to increase C sequestration in temperate coastal wetland.     

罗布泊地区红柳沙包年层的研究意义

红柳沙包是干旱区发育的一种生物地貌类型。罗布泊地区的红柳沙包主要分布在塔里木河、孔雀河、米兰河等三角洲地带。通过研究发现其巾有些沙包具有清晰的“年层”构造,与树木年轮一样,具有计年和储存环境信息的功能,可以用来探讨和恢复过去气候和环境变化。但由于红柳生长发育规律和研究区环境的复杂性,利用红柳沙包年层在研究环境演变,在理论和实践上都有待进一步完善和提高。     

Pathogenicity of vibrios in fish: An overview

Bacteria of the genus Vibrio are ubiquitously distributed in the marine environment. Due to the rapid expansion of intensive mariculture and the consequent deterioration of culture conditions, more and more Vibrio spp. have been recognized as pathogenic agents in outbreaks of vibriosis, a serious epizootic disease affecting most wild and farmed fish species worldwide, which has become the most important limiting factor for the development of intensive mariculture industry. Attempts have been made to understand the pathogenicity of vibrios in host fish with the ultimate aim of elucidating the best means for disease control. After an extensive literature survey of the recent advances in the field of fish vibriosis, the pathological changes, virulence factors and associated potential pathogenic mechanisms, transmission routes and related environmental factors involved in outbreak of vibriosis, as well as the controlling strategies are reviewed in the present paper.     

网箱养殖罗非鱼综合症的病理组织学研究

于1989至1992年对水库网箱养殖罗非鱼综合症各发病期、各症状型的病鱼进行了病理组织学研究。研究结果表明:网箱养殖罗非鱼综合症的病理基础是肝肾功能障碍,病鱼的肝、肾、脾、肠、鳃、性腺、脑均有不同程度的坏死或变性。本文还对细菌继发性感染,各症状型的病理学变化及防治对策作了讨论。     

不同种植方式下柽柳光合生理参数光响应特性研究

为选择合适的间套模式,在塔干沙漠南缘绿洲外围利用Li-6400光合作用仪对四种种植模式(行间混交、带状混交、块状混交、块状套作)下多年生多枝柽柳(Tamarix ramasissima ledeb.)的光合水分生理指标对有效光辐射(PAR)的响应进行测定。结果表明:(1)柽柳具有高光饱和点(679~822μmol·m^-2·s^-1)和高光补偿点(50.0~61.1μmol·m^-2·s^-1)。(2)不同的光照强度和种植方式对柽柳净光合速率有明显的影响(p<0.01),当0< PAR< 1500μmol·m^-2·s^-1,除胞间CO₂浓度(Ci)外柽柳的各项生理指标均随光照的增强而增加。(3) PAR>1500μmol·m^-2·s^-1后,块状套作和块状混交气孔导度(Gs)下降,行间混交和带状混交Gs则随光强增加而递增;带状混交下胞间CO₂浓度(Ci)和蒸腾速率(Tr)均随光强增加而递增,其他3种种植方式下Ci和Tr均呈递减或平稳趋势。(4) 4种种植方式下柽柳光响应曲线的特征参数存在着差异(P<0.05),带状混交下的光饱和速率、光饱和点、表观量子效率均最高,块状混交的暗呼吸速率最大,水分利用效率(WUE)随着光强的增强而逐步增大,依次表现为带状混交>块状混交>行间混交>块状套作。通过4种种植方式柽柳光响应特征的综合分析可知,带状混交下的柽柳具有高光合和高水分利用效率的特点,对于极端干旱的塔南地区而言,该种植方式下的柽柳生理特征表现出最好的适应性。     

不同生物量的乳酸杆菌对对虾养殖池3种常见优势微藻的影响

在实验室条件下,分别把对虾养殖池常见优势种——微绿球藻（Nannochloropsis oculata）、隐藻（Cryptomonas erosa）和颤藻（Oscillatoria）与乳酸杆菌（Lactobacillusspp.）在对虾养殖水体中共同培养,研究不同生物量的乳酸杆菌对3种微藻的影响.实验分4组,乳酸杆菌分C1（10^3cells/cm^3）组、C2（10^4cells/cm^3）组、C3（10^5cells/cm^3）组、C4（10^6cells/cm^3）组四个浓度.结果表明：不同生物量的乳酸杆菌对不同微藻的影响有很大差异.C1（10^3cells/cm^3）乳酸杆菌对微绿球藻的生长没有明显的影响,对隐藻和颤藻生长有明显的抑制作用.C2（10^4cells/cm^3）乳酸杆菌对微绿球藻和隐藻生长有明显的促进作用,对颤藻生长有明显的抑制作用.C3（10^5cells/cm^3）乳酸杆菌对隐藻生长有明显的抑制作用,对颤藻的生长有明显的促进作用.C4（10^6cells/cm^3）乳酸杆菌对微绿球藻和颤藻生长有较明显的促进作用,对隐藻生长有微弱的抑制作用.无论是抑制作用还是促进作用,这种作用都随实验时间的延长而减弱.     

Resource Partitioning Among Planktivorous Fish Larvae and Fry in a Mediterranean Coastal Lagoon

Resource partioning among the planktivorous stages of eight fish species occurring in a Mediterranean coastal lagoon was studied. Five species were migratory mullets that spawned in the sea (Liza ramada, L. aurata, L. saliens, Chelon labrosusandMugil cephalus), while the other three species were resident and spawned in the lagoon (Atherina boyeri, Cyprinus carpioandGambusia holbrooki).Mullet fry exhibited similar diets, based on the consumption of zooplanktonic Crustacea such as copepods and cladocerans, although adult chironomids were also important.Gambusia holbrookiandA. boyerifed on small prey such as copepod nauplii, copepodites and rotifers, whileC. carpioconsumed larger prey preferentially (cladocerans and copepods).According to the trophic overlap and niche width results, seven species pairs could be competing in the estuary, although further experimental evidence is still required.     

基于线粒体cyt b基因序列差异的组合PCR技术快速鉴定五种鳗鲡养殖种类的方法研究

在自然或人为因素下容易出现鳗苗种质混杂的现象,由于鳗鲡苗种在形态上十分相似,难以区分。为了保障鳗农的合法利益和提高养殖效益,急需建立一种能够在现场快速、高效使用的鳗鲡种质鉴定方法。本研究通过比对找出5种常见鳗鲡养殖种类:日本鳗鲡(Anguilla japonica)、美洲鳗鲡(A.rostrata)、花鳗鲡(A.marmorata)、太平洋双色鳗鲡(A.bicolor pacifica)、欧洲鳗鲡(A.anguilla)线粒体细胞色素B(cytochrome b,cyt b)基因的差异序列,基于5个cyt b基因序列差异较大的片段,设计多对引物,分别经过PCR验证和条件优化,挑选出4对引物:aj S1/A1、r-a S1/A2、bp-m S5/A3和m-a S4/A4。将这4对引物组合在同一个反应体系中进行PCR扩增,进行条件优化,筛选出组合PCR的最优条件:退火温度为58oC;退火时间为45s;循环数为27。结果表明,通过扩增产物凝胶电泳中条带的有无及大小可快速准确的鉴定出五个鳗鲡种类。本研究建立的组合PCR方法在3小时内可完成整个种类鉴定过程,同时可使用便携式小型仪器完成操作,可满足现场快速、高效鉴定的要求。此外,通过MEGA5.0软件构建5种鳗鲡线粒体cyt b基因序列NJ进化树,发现花鳗鲡和太平洋双色鳗鲡先聚为一支,再与日本鳗鲡聚在一起,而欧洲鳗鲡和美洲鳗鲡聚在一起,进化树图显示的遗传距离和它们的地理分布的远近相似。