Application of acoustic Doppler current profiler combined with a scientific echo sounder for krill Euphausia pacifica density estimation

ABSTRACT:   An application of the acoustic Doppler current profiler (ADCP, 153.6 kHz) in combination with a scientific echo sounder (EK60, 38 and 200 kHz) was investigated to estimate the density of krill Euphausia pacifica . The acoustic backscattering strength from sound scattering layers was compared with biomass estimates from midwater trawls. Euphausia pacifica was targeted among mixed species populations in the sound scattering layer in the offshore Funka Bay area of Hokkaido, Japan. The frequency characteristics of acoustic backscattering by krill were calculated using a distorted wave Born approximation scattering model at three frequencies. Krill aggregations identified from the EK60 data were extracted as the mean volume backscattering strength difference between two frequencies. They were then used to identify similar aggregations in the ADCP data by matching observation times and depths for the two methods, which were applied simultaneously. Results from the comparison of the mean volume backscattering strength and the density calculated from the ADCP and EK60 showed that ADCP can be used to measure density and spatial–temporal distribution of krill aggregations. Current speed and direction at the study site were found to be 16.1 cm/s and 187.0°, respectively, and krill speed and direction (including the current component) were found to be 19.8 cm/s and 172.2°, respectively. Based on the ADCP data, the net speed and direction of the krill aggregations were found to be 5.9 cm/s and 128.0°, respectively.     

家禽卵泡发育相关生长因子的研究进展

胰岛素样生长因子(IGF)家族、表皮生长因子(EGF)家族和转化生长因子-β(TGF-β)超家族成员的功能涉及家禽卵泡细胞增殖分化、类固醇激素生成、促性腺激素的功能调节、卵泡选择和排卵等过程。本文综述了IGF、EGF、TGF-β及其他相关生长因子对家禽卵泡发育调控的研究进展,旨在为进一步研究家禽卵泡的生长、发育和排卵机制提供帮助。     

伊维菌素控制春乏期羊狂蝇蛆病试验

目的为有效预防和控制羊狂蝇蛆病的发生。方法选用伊维菌素在羊狂蝇成虫完全消失的11月进行驱杀羊狂蝇蛆试验,并以敌敌畏熏蒸作为对照。结果在来年羊狂蝇成蝇出现之前的长达7个月的冬春枯草季节,伊维菌素组驱虫率和驱净率均保持100％,而敌敌畏熏蒸组驱虫率保持94．69％,驱净率仅保持60％。结论选择每年11月份用伊维菌素驱虫一次,可使羊在冬春季节无任何阶段羊狂蝇幼虫寄生。     

基于叶绿体trnL-F序列对广义披碱草属物种的系统进化研究

广义披碱草属包括了披碱草属、鹅观草属、猬草属、裂颖草属和仲彬草属。为深入研究这5个小麦族多年生属的系统地位、母本来源及St染色体组的来源和分化等问题,本研究根据叶绿体DNA trnL-F序列构建了系统树和网状结构图。结果表明,1)广义披碱草属物种的母本不完全来源于拟鹅观草属的St染色体组,其中黑药仲彬草和梭罗仲彬草的母本染色体组为P染色体组,Hystrix duthiei及长芒猬草的母本染色体组为Ns染色体组;2)系统树中反映了P、W和St染色体组之间具有较近的亲缘关系,它们与H和Ns染色体组的关系较远;3)仲彬草属中黑药仲彬草和梭罗仲彬草与冰草属的二倍体物种聚类在一起,表明黑药仲彬草和梭罗仲彬草与冰草属的关系较近;猬草属中猬草聚在St支中,而H. duthiei和长芒猬草包括在Ns支中,表明它们具有不同的染色体组组成;4)5个不同地理分布的具有St染色体组的拟鹅观草属二倍体物种没有形成一个单系组,表明St染色体组在二倍体物种中存在一定程度的分化;在异源多倍体物种中,其St染色体组的质体序列构成了不同的分支,表明St染色体组在多倍体物种中也具有分化;5)亚洲分布的拟鹅观草属二倍体物种可能参与了大部分欧亚物种的起源,北美分布物种的St染色体组可能来源于北美的拟鹅观草属物种;有些物种在多倍化起源过程中可能发生了重复杂交过程。     

10种作物秸秆的营养品质分析

饲草作物秸秆是黄土高原农区重要的饲料来源,但是适宜饲草作物秸秆的选择是该地区畜牧业发展的重要工作。本研究应用主成分和聚类分析法以吸附水、粗蛋白、粗脂肪、粗纤维、中性和酸性洗涤纤维、灰分、无氮浸出物、碳水化合物和有机质消化率为指标构建综合评价模型,对静宁地区小麦(Triticum aestivum)、玉米(Zea mays)、高梁(Sorghum bicolor)、青稞(Avena nuda)、燕麦(A. sativa)、土豆(Solanum tuberosum)、谷子(Setaria italica)、糜子(Panicum miliaceum)、大豆(Glycine max)和豌豆(Pisum sativum)10种饲草作物秸秆进行了综合评价。结果表明,秸秆营养品质从高到低的次序为糜子、大豆、豌豆、谷子、青稞、燕麦、高粱、土豆、玉米、小麦。聚类分析的结果为糜子、大豆、豌豆和燕麦为一类,谷子和土豆为一类,小麦、玉米和高粱为一类,青稞单独为一类。     

鱼类血液基因组DNA提取方法优化

The genomic DNA extracted from frozen whole blood of rainbow trout with methods of chloroform-potassium acetate, rapid genomic DNA extraction （RGDE） , improved RGDE, traditional phenol-chloroform and DNA reagent kit respectively, and detected by agarose gel electrophoresis. The results showed that mothode of improved RGDE can obtain better genomie DNA of fish. Then, the effect of extracting with improved RGDE methods were compared by ultraviolet spectrophotometric method with other mothods such as traditional phenol-chloroform from blood or muscle and DNA reagent kit from blood. The results showed that the average concentration of DNA extracted with method improved RGDE was 1 050 ng/μL, and was very significant higher than that by DNA kit or by phenol- chloroform, and the average output of DNA was 1 575μg/mL, and the rate of A260/A280 was between 1.65 - 1.97. It only spent 2 hours to extract DNA with the method of improved RGDE, and there were many obvious merits such as quick speed, low cost, no pollution and no using specific installations and so on, and to amplify by random primers, the rusuhs was stable,and the electrophoresis banding was clear.     

大鲵虹彩病毒贵州分离株MCP基因的克隆与原核表达

根据Gen Bank中大鲵虹彩病毒主衣壳蛋白MCP(major capsid protein,MCP)基因序列(序列号:KF512820),设计一对特异性引物,以大鲵虹彩病毒贵州分离株基因组DNA为模板,PCR扩增大鲵虹彩病毒MCP基因并测序,与Gen Bank中大鲵虹彩病毒MCP基因进行比对,然后将其亚克隆到原核表达载体p ET-32a(+)中,转化大肠杆菌BL21(DE3)感受态细胞,经IPTG诱导后进行Western blot分析。结果显示:PCR扩增出长度为1 392 bp的片段,与Gen Bank中大鲵虹彩病毒MCP基因核苷酸序列相似性为99.7%~99.9%,SDSPAGE电泳显示该重组蛋白的相对分子质量约为67×103。免疫原性检测结果表明,该重组蛋白可与兔抗大鲵虹彩病毒阳性血清特异性反应,具有免疫原性。     

三种不同材质小菜蛾性诱剂诱芯田间诱蛾效果比较

利用挂胶型诱捕器比较了常规长效诱芯、双孔扁垫柱型诱芯和圆锥柱型诱芯3种不同材质和形状的性诱芯诱捕小菜蛾的效果。结果表明:双孔扁垫柱型诱芯诱蛾效果为最佳,是圆锥柱型诱芯诱蛾量的1.61倍,是常规长效诱芯诱蛾量的1.16倍。在持效期方面,双孔扁垫柱型诱芯同常规长效诱芯相同,好于圆锥柱型诱芯。     

小麦花培育种技术研究

对5个小麦不同组合基因型的F1,F2,F3花药进行培养,结果表明:不同组合基因型在同一杂种世代的花药愈伤组织诱导率、愈伤组织鲜重和绿苗分化率等方面存在较大差异,而同一组合基因型在不同杂种世代的花药愈伤组织诱导率、愈伤组织鲜重和绿苗分化率等方面差异较小。花药愈伤组织诱导率与绿苗分化率具有显著的相关性(r2=0.903)。以石4185为亲本配制的两个组合基因型,在F1,F2,F3都表现出较高的花药愈伤组织诱导率和绿苗分化率,说明石4185是理想的花培育种桥梁亲本。     

西瓜中类胡萝卜素的高效液相色谱法分析

通过高效液相色谱法对西瓜中的类胡萝卜素进行分析,采用Vydac201TP54C18色谱柱,比较2种不同流动相的检测结果,表明乙腈:甲醇:二氯甲烷=75:20:5(V:V:V)的分离效果较好;初步定性分析确定西瓜中含有7种以上类胡萝卜素。