不同栽培方式对水稻细菌性基腐病发生的影响

为明确不同栽培方式与水稻细菌性基腐病危害程度的关系,在田间比较了5种水稻栽培方式(直播、小苗手插、大苗手插、小苗机插和大苗机插)对病害发生程度和水稻产量损失的影响。结果表明,直播田发病最轻,水稻产量损失最小;大苗机插发病最重,产量损失最大。移栽种植时,小苗机插发病较轻,病丛率显著低于小苗手插、大苗手插和大苗机插。因此,从细菌性基腐病控制的角度,在生产中推广直播或者小苗机插的栽培方式更有利于控制该病害发生。     

Optimization of fixation methods for image analysis of the hepatopancreas in whiteleg shrimp,Penaeus vannamei (Boone)

Pathology in penaeid shrimps relies on histology, which is subjective, time‐consuming and difficult to grade in a reproducible manner. Automated image analysis is faster, objective and suitable for routine screening; however, it requires standardized protocols. The first critical step is proper fixation of the target tissue. Bell & Lightner's (A Handbook of Normal Penaeid Shrimp Histology, 1988, The World Aquaculture Society, Baton Rouge) fixation protocol, widely used for routine histology of paraffin sections, is not optimized for image analysis, and no protocol for frozen sections is described in the available literature. Therefore, the aim of this study was to optimize fixation of the hepatopancreas (HP) from whiteleg shrimp (Penaeus vannamei) for both paraffin and frozen sections using a semiquantitative scoring system. For paraffin sections, four injection volumes and three injection methods were compared, for frozen sections, four freezing methods and four fixation methods. For paraffin sections, optimal fixation was achieved by increasing threefold the fixative volume recommended by Bell and Lightner, from 10% to 30% of the shrimp body weight, combined with single injection into the HP. Optimal fixation for frozen sections was achieved by freezing the cephalothorax with liquid nitrogen, followed by fixation of the section with 60% isopropanol. These optimized methods enable the future use of image analysis and improve classical histology.     

不同烹饪方式及体外模拟消化对凡纳滨对虾主要过敏原原肌球蛋白免疫活性的影响

本研究选用水煮、油炸和红烧3种烹饪方式分别处理凡纳滨对虾,并且对烹饪后的虾肉进行体外模拟唾—胃—肠液连续消化,以调查烹饪处理后过敏原原肌球蛋白的免疫活性变化状况。采用电泳、免疫印迹和间接ELISA方法评价样品中主要过敏原原肌球蛋白的变化情况。SDS-PAGE结果显示,3种烹饪处理虾肉样品中TM条带无明显变化,表明TM在烹饪处理时基本不发生降解;免疫印迹和间接ELISA结果显示,水煮、油炸和红烧3种烹饪处理虾肉中TM免疫活性分别降低2.08%、11.33%、15.56%;而烹饪后虾肉的体外模拟消化产物的免疫活性丢失显著,水煮、油炸和红烧处理的免疫活性分别下降86.90%、88.94%、97.39%。研究表明,虾类TM免疫活性的降低主要发生在肠液消化阶段,3种方式烹饪处理能够使TM免疫活性降低,并且红烧处理可明显降低TM的免疫活性。本实验为过敏原消减机制的研究和低致敏性水产品的开发提供了理论依据。     

海水工厂化养殖生产能力评估方法

生产能力反映出海水工厂化养殖企业的可蓄养生物资源量,是评估海水工厂化养殖企业生物资源资产的重要指标,本文根据海水工厂化养殖的特点,提出了评估海水工厂化养殖企业生产能力的技术思路与原则,并在详细论述影响生产能力主要因素的基础上,提出了具体的评估方法,同时阐述了此方法的实用性和对完善海域评估方法的意义。     

９种交配组合鳢的人工繁殖试验

运用人工催产的方法进行了9种交配组合鳢的人工繁殖试验,9种组合来源于乌鳢(Channa argus)、斑鳢(C.maculate)和杂交鳢(Hybrid snakehead)彼此之间的交配繁殖.结果表明,无论采用何种孵化方式,9种交配组合所产卵的受精率和孵化率高低顺序基本一致,且各组合间都存在显著差异.交配组合斑鳢(♀)×斑鳢(♂)、斑鳢(♀)×杂交鳢(♂)、杂交鳢(♀)×斑鳢(♂)及杂交鳢(♀)×杂交鳢(♂)在繁殖过程中,其受精率和孵化率高于其他组合,具有较强的繁殖优势,但其子代的生产性能优势还有待进一步研究.孵化方式对受精卵的发育与孵化有重大影响,其中以微流水孵化方式时的受精率和孵化率最高、孵化效果最好.雄亲鱼的重复催产次数会影响受精率及孵化率,一般以重复利用2～3次为宜.     

3种典型潮滩沉积物微塑料分离方法研究

针对我国海岸带环境中微塑料监测方法缺乏标准化和系统化问题,探讨和改进了直接浮选法(方法 A)、分液漏斗法(方法 B)和容量瓶法(方法 C)3种典型的潮滩沉积物微塑料检测方法,并探究了沉积物粒径和聚合物类型对其分离效果的影响。经检验,3种方法对潮滩沉积物中尺寸约为1 mm的高密度聚乙烯(HDPE)、聚氯乙烯(PVC)和聚丙烯(PP)等5种常见聚合物颗粒的平均分离效率达到(91±7)%,且聚合物类型并不会影响分离效果(P0.05)。方法 B在分离效率和稳定性方面明显优于其他2种方法(P0.05),对于粗砂(0.5~1.0 mm)、粉砂(0.004~0.063 mm)和泥质(0.004 mm)3类潮滩沉积物中的微塑料颗粒均有着良好的分离(95%±3%)。沉积物粒径会显著影响提取效果,呈现出随着沉积物粒径的增大、微塑料分离效率提高的趋势(P0.05)。利用方法 B对系列现场调查样品进行了测定,结果显示,海州湾北部绣针河口、赣榆港码头和高公岛乡潮滩沉积物中微塑料数量丰度分别为34.97~144.33 n/kg、43.70~119.9 n/kg和372.98~1 103.02 n/kg;质量浓度分别为2.56~10.70 mg/kg、1.01~5.92 mg/kg和3.36~8.48 mg/kg。     

渔用可降解材料的研究进展与展望

可降解渔具材料的研发与应用是减轻"幽灵捕捞"、保护海洋渔业资源和生态环境、实现可持续发展的有效途径之一。淀粉基材料、聚己内酯(PCL)、聚乳酸(PLA)、聚丁二酸丁二醇酯(PBS)等材料具有可完全生物降解、可加工、可再生等特点,作为不可降解渔用合成纤维材料的替代品,可为生物降解高分子材料在渔业领域的应用开辟新的途径。主要综述了近年来国内外有关淀粉基材料、 PCL、PLA、PBS 4种渔用可降解高分子材料的性能、生物降解机理及其与天然高分子共混、合成高分子共混改性的研究进展,介绍了加工工艺、表面处理、添加剂等对复合体系性能的影响,并分析了可降解材料在渔业上的应用及发展前景,以期为研发价格低廉、综合性能优越的可降解渔用材料提供参考。     

Effects of temperature, wind and spawning stock biomass on recruitment of Arcto-Norwegian cod

Sea temperature has earlier been shown to have a large influence on the recruitment of Arcto-Norwegian cod, Gadus morhua. We here hypothesize that this linkage is partly due to the direct effect of temperature on larval and juvenile growth. Secondly, temperature acts as a proxy for both biotic and abiotic factors influencing recruitment. Indices of abundance of early juvenile cod (2–3 months old), 0-group cod (4–5 months old) and 3-year-old cod are analysed in more detail against the environmental temperature, wind stress components, wind-induced turbulent energy and the spawning stock biomass. To deal with autocorrelation, non-stationar-time and nun-normality, which complicate a statistical time series analysis, randomization and Box-Jenkins methods are applied. In addition to the important effect of high sea temperature during the early life stage in forming strong year classes, the results show that the spawning stock biomass is nearly as important. Also, alongshore southerly wind stress anomalies during the period of pelagic drift (from April through summer) and offshore wind stress anomalies during egg and early larval stages (in April) act favourably on recruitment. The beneficial effect of southerly wind anomalies could he linked partly to high temperature, but the flux of zooplankton-rich water from the Norwegian Sea into the feeding areas of the Barents Sea may also be increased. The favourable influence of offshore winds in April is less predominant and causal links are also less clear; possible explanations for this might be increased offshore spreading of eggs and early larvae, resulting in reduced risk of predation, and increased compensation inflow of intermediate Norwegian Sea water which, in this restricted period of time, has a high concentration of spawning copepods suitable as prey for the developing cod larvae.     

赤潮对日本养殖业的危害及其防治对策

报导了日本濑户内海１９７２年至１９８４年和西海岸１９８５年至１９９２年赤潮对海水养殖业所造成的经济损失情况，给出了发布赤潮注意报和赤潮警报期间应该采取的防治措施。