Effects of stocking density on haematological parameters,growth and fin erosion of great sturgeon (Huso huso) juveniles

The influence of stocking density (1, 2, 4, 6 and 8 kg m^?2) was investigated on haematological parameters, growth and fin erosion of great sturgeon (Huso huso) juveniles for a period of 8 weeks. The mean weight of fish at the start of trial was 93.13±1.04 g. After 8 weeks of rearing, the mean weight was 362.4, 319.7, 267, 242.1 and 211.1 in densities 1–8 kg m^?2 respectively. The results of this study showed that growth parameters, including condition factor, weight, weight gain, feed conversion ratio, specific growth rate and body weight increase, had a statistically significant difference among treatments (P<0.05). A significant difference (P<0.05) was observed in haematocrit, but the other haematological parameters, including red blood cells, white blood cells (WBC), haemoglobin concentration, mean corpuscular haemoglobin, mean corpuscular volume, mean corpuscular haemoglobin concentration and differential WBC count, showed no significant effect with stocking density (P>0.05). At the end of the experiment, stocking density had no significant effect on plasma cortisol and glucose concentration. The fin length (dorsal, anal, ventral, pectoral and caudal) of fish was measured to calculate the fin index. According to this index, dorsal, anal, ventral and pectoral fins showed no significant difference among treatments (P>0.05), but the erosion of the caudal fin was significantly different between fish held on 6 and 8 kg m^?2 (P<0.05). These results showed that rearing density has a major effect on the growth indices of H. huso. Unlike many other fish, great sturgeon exhibited lower stress responses to high stocking density. This indicates that they are more tolerable to rearing conditions in high stocking densities. With respect to the various effects that density causes on growth, fin erosion and physiological and haematological parameters, better understanding of these phenomena considering different levels of density could have a beneficial impact on many rearing steps of this species.     

利用SRAP分子标记技术鉴定大白菜种子纯度

以大白菜品种多抗3及其父母本为研究材料,利用SRAP（相关序列扩增多态性）分子标记方法,通过对54对SRAP标准引物的筛选,获得了能区分大白菜多抗3及其亲本的引物Me4F/Em3R。采Me4F/Em3R引物对对5份多抗3系列商品种子纯度进行检验,种子的纯度分别为75.5%、72%、80.5%、68%和73%,与田间种植纯度鉴定结果符合率分别为94.6%、89.3%、93.2%、95.5%和91.25%。说明利用SRAP分子标记方法对多抗3大白菜一代杂种进行快速、准确的纯度鉴定是可行的。     

西南地区普通小麦1BL/1RS易位系的DArT分子标记鉴定

为了准确了解小麦品系中1BL/1RS易位系的存在,利用7 000多个DArT分子标记(Diversityarrays technology,多样性微阵列技术)对87个普通小麦品系进行扫描,总共获得1 750个稳定的多样性的分子标记(P>80)。这些标记的多态性信息含量指数(PIC)的范围是0.03～0.5,平均值为0.35(P>80)。根据DArT标记的可整合性,利用1B染色体上的DArT数据进行主坐标分析(Principal-Coordinates Analysis,PCoA),可以把实验材料划分为两个群,并且确定一个群是由1BL/1RS易位系组成,另一个群由非1BL/1RS易位系组成。同时,利用非加权组平均法(Unweighted pair-group method with arithmetic means,UPGMA)进行聚类分析,调查了材料之间的遗传关系,结果显示,实验材料同样聚集为两个群,一个群由1BL/1RS易位系组成,包含两个亚群;另一个群由非易位系组成,包含六个亚群。研究证实,DArT标记不仅可以调查小麦全基因组的遗传多样性,而且利用它的可整合性能够准确鉴定研究材料中的1BL/1RS易位系。     

基因型和环境对小麦种子活力的影响

为了明确环境、基因型及其互作对小麦种子活力的影响,以湖北省小麦区域试验三个试点的16个小麦新品种(系)为材料,对收获后的种子进行发芽率、幼苗干重及简易活力指数的计算并进行了统计分析,结果表明:(1)发芽率、幼苗干重及其简易活力指数在地点间、品种(系)间差异均达到了极显著水平,且品种(系)间的差异均比地点间的差异大,发芽率和简易活力指数的地点×品种(系)互作(GEI)间差异也达到了极显著水平。(2)发芽率和简易活力指数以武汉最高,且与其他地点的差异达极显著水平;而幼苗干重则以荆州最高,与武汉差异不显著。(3)鄂麦27和楚0805的发芽率较高,襄麦27和河科大9612的幼苗干重最高,而鄂麦27的简易活力指数最高。(4)简易活力指数与发芽率呈极显著正相关,与幼苗干重呈不显著的正相关,而发芽率与幼苗干重呈不显著的负相关。     

黄芪种子休眠与休眠解除方法的研究

从介绍种子的萌发阶段出发,阐述了黄芪种子的休眠机制及其影响因素,并详细论述了促进黄芪种子发芽的处理方法,包括机械破损、沙磨处理、浓硫酸处理、温烫浸种及赤霉素处理等。     

Development and application of fluorescence in situ hybridization (FISH) method for simple and rapid identification of the toxic dinoflagellates Alexandrium tamarense and Alexandrium catenella in cultured and natural seawater

ABSTRACT:   The toxic dinoflagellates Alexandrium tamarense (Lebour) Balech and A. catenella (Whedon and Kofoid) Balech produce potent neurotoxins, such as saxitoxin and gonyautoxin and have been mainly responsible for paralytic shellfish poisoning (PSP) in Japan. To prevent a negative effect on the fishery industry, it is necessary to identify these toxic species precisely and rapidly before and during the bloom. In this paper, a rapid and simple protocol of a fluorescence in situ hybridization (FISH) method using ribosomal RNA (rRNA)-targeted probes has been established for identifying the cultured strains and natural cells of A. tamarense and A. catenella . Using the FISH method established in this study, it was possible to identify these toxic species species-specifically and rapidly, within 30 min. The procedure of detection constituted three steps: (i) fixation/dehydration; (ii) hybridization; and (iii) washing; this made the identification simple. Moreover, this method did not require either special techniques or equipment, and the cost for detection was low. The specificity, rapidity, and simplicity of the developed method suggest that it might be useful for routine monitoring of these toxic microalgae.     

太湖中大银鱼_太湖新银鱼和寡齿新银鱼群体的遗传结构

利用ＲＡＰＤ技术对太湖中的大银鱼,太湖新银鱼,寡齿新银鱼的遗传结构进行了研究,共在太湖中的６个采样片采到大银鱼和太湖新银鱼样品,在两个采样片得到了寡齿新银鱼的样品。结果表明,太湖中不同水域的三种银鱼没有明显的遗传差异,三种银鱼中,大银鱼的遗传相似性指数显示最大,太湖新银鱼的次之,寡齿新银鱼的最小,说明大银鱼的遗传变异性最小,寡齿新银鱼的最大,太湖新银鱼的遗传变异性界两者之间。     

星斑川鲽MHCⅡ恒定链Ii基因的克隆和表达特性

为了研究星斑川鲽MHCⅡ类分子的作用及调控机制,实验通过SMART-RACE技术克隆得到了星斑川鲽MHCⅡ恒定链(MHCⅡIi)的全长cDNA序列,其长度为1766 bp,包含135 bp的5′非编码区、837 bp的开放阅读框和794 bp的3′非编码区。该基因共编码279个氨基酸。理论分子量为30.848 ku,等电点为6.89。与已知物种MHCⅡIi进行同源性比对,结果与狼鲈、紫红笛鲷和鳜关系较近,同源性均为79%。利用quantitative realtime PCR(qRT-PCR)技术检测了MHCⅡIi在星斑川鲽不同组织中的表达,以及爱德华氏菌感染前后对该基因在不同组织中表达水平的影响,结果显示:在脾脏、头肾、肝脏、后肠、性腺、心脏、血液、鳃和肌肉组织中,MHCⅡIi mRNA均有表达,但在表达量上有明显差异,脾脏和头肾组织相对表达水平较高,鳃、血液、肌肉、心脏和性腺中的表达水平较低。病原感染后,免疫相关组织脾脏和头肾的表达水平升高最明显,肝脏和后肠的表达水平也略有升高,但变化不明显。本研究可为星斑川鲽MHCⅡ类分子的作用机理提供理论依据,同时为海水养殖鱼类的抗病遗传育种工作提供研究基础。     

Density separation of soil organic matter across three land uses in calcareous soils of Iran

ABSTRACT

The aim of this study was to examine the usefulness of physical and chemical fractionation in quantifying soil organic matter (SOM) in different stabilized fraction pools. Soil samples from three land use types in Lorestan province, Southwest Iran were examined to account for the amount of organic carbon and nitrogen in different SOM fractions. Size/density separation and chemical oxidation methods were applied to separate the SOM fractions including particulate organic matter (POM), Si + C (silt and clay), DOC (dissolved organic C), rSOM (oxidation-resistant organic carbon and nitrogen) and S + SA (sand and stable aggregates). The values obtained for TOC, TN, and HWC were highest in forest lands followed by the range and agricultural lands. Among the SOM fractions, S + SA showed the highest values (5.75, 5.77 and 20.6 g kg^?1 for agriculture, range and forest lands respectively) followed by POM, Si + C, rSOM, and DOC. The concentrations of C and N in the labile fractions obtained the higher values than in the stabilized fractions. Forest lands had the highest amounts of organic C and N among all fractions whereas agricultural lands showed highest values for inorganic C content of soils in different fractions.     

基于iTRAQ质谱分析技术筛选南方型紫花苜蓿根部响应盐胁迫差异表达蛋白

为了从蛋白质水平上揭示南方型紫花苜蓿(Medicago sativa ‘Millennium’)适应盐胁迫的分子机制,本研究以30 d苗龄的南方型紫花苜蓿实生苗为材料,分析正常培养和250 mmol/L NaCl处理72 h后根中的蛋白表达变化,采用同位素相对标记与绝对定量技术(isobaric tags for relative and absolute quantitation,iTRAQ)结合双向液相色谱与串联质谱(2-dimensional liquid chromatography-tandem mass spectrometry,2D-LC-MS/MS)定量蛋白质组技术鉴定南方型紫花苜蓿根部响应盐胁迫差异表达蛋白,对所获得差异蛋白进行生物信息学分析,筛选出可能耐盐潜在靶标蛋白.同时,选择5个差异表达蛋白进行实时荧光定量PCR(qRT-PCR)验证.结果表明,共鉴定3 857种定量蛋白,534种差异蛋白(变化倍数≥1.2,P＜0.05),其中表达上调的281种,表达下调的253种.基因本体(Gene Ontology,GO)分子功能提示这些差异性蛋白主要参与转运活性、催化活性和酶调控活性.京都基因与基因组百科全书(Kyoto Encyclopedia of Genes and Genomes,KEGG)通路显著性富集于代谢途径、次生代谢产物生物合成、苯丙氨酸代谢和核糖体等(P＜ 0.05,错误发现率(false discovery rate,FDR)＜ 0.05).成功鉴定的差异蛋白分别涉及到信号传递(8.99％)、抗氧化物(7.68％)、防御(5.61％)、蛋白质合成、加工和降解(14.79％)、能量产生与转运(5.81％)、代谢(26.97％)、膜与胞内运输(5.62％)和细胞结构、分裂和细胞骨架(2.06％)等.差异表达蛋白中与信号传递、抗氧化物和防御等相关的蛋白表达量总体上调,而与代谢和能量产生与转运相关蛋白表达量总体下调.qRT-PCR实验发现,mRNA与蛋白质表达水平并不一致.研究发现组氨酸磷酸转移蛋白、丝裂原活化蛋白激酶、h类硫氧还蛋白、蛋氨酸亚砜还原酶基因、鸟苷二磷酸(guanosine diphosphate, GDP)解离抑制因子、脂质转移蛋白、β-1,2-木糖基转移酶和H2A/H2B/H3/H4核心组蛋白等可能是紫花苜蓿耐盐潜在靶标蛋白.本研究采用iTRAQ结合2D-LC-MS/MS技术,有效地筛选出南方型紫花苜蓿根部响应盐胁迫差异表达蛋白,为深入认识紫花苜蓿盐胁迫的应答分子调控机制奠定了坚实的基础.