基于微卫星标记的真鲷放流群体与增殖海域群体遗传变异比较分析     

赵雨  孙典荣  单斌斌  刘岩  杨长平  周文礼 《海洋科学》2020,44(10):66-73

真鲷（Pagrus major）是中国沿岸海域重要的经济种类,增殖放流作为修复真鲷渔业资源、恢复自然群体的方法,现已在中国被广泛地应用。然而,将大量人工繁育的苗种投入自然海域中,可能会对自然群体造成一定程度的遗传学影响。因此,在开展真鲷增殖放流的同时,应进行遗传监测。本研究使用7对真鲷微卫星标记,对2017年于防城港沿岸海域开展的真鲷增殖放流进行遗传监测,对比分析了真鲷亲体、放流真鲷苗种以及放流后混合群体的遗传多样性。研究结果表明,真鲷亲本群体与真鲷放流群体的等位基因丰度（13.525 3,16.428 6）和期望杂合度（0.792 7,0.814 5）没有明显的差异,表明在苗种繁育过程中,没有出现遗传多样性丢失的现象。真鲷放流群体和放流后混合群体的期望杂合度（0.814 5,0.822 8）、等位基因丰度（16.428 6,16.755 5）相似,表明真鲷放流群体和放流后混合群体处于相同的遗传多样性水平。3个群体的多态信息含量为0.768 8~0.805 5,表明3个群体均具有较高的遗传多样性。群体间遗传分化指数（0.016 667）和遗传距离（0.265 375~0.301 915）的结果显示群体间的遗传分化微弱,未形成明显的遗传分化。因此,可认为本研究中真鲷增殖放流未对放流后混合群体造成明显的遗传学影响。本研究为今后真鲷增殖放流遗传监测提供了理论参考依据。  相似文献   

有害藻华的宏条形码分析:机会与挑战   总被引：3，自引：3，他引：0  

陈楠生 《海洋科学》2020,44(7):116-134

宏条形码分析（metabarcoding analysis）是通过对野外样本的分子标记（即条形码）进行PCR扩增、测序,并利用测序结果分析野外样本物种组成、物种相对丰度,及其时空动态变化。这项在近20年里逐步发展起来的分子技术,得益于DNA测序技术的快速发展,包括测序通量的提升和测序成本的降低,以及生物信息学分析方法的快速开发。基于可操作分类单元（operational taxonomic units,OTUs）分析方法,特别是最近的扩增子序列变异（amplicon sequence variants,ASVs）方法的开发,极大促进了宏条形码分析的应用。在世界及我国的海洋生态领域,宏条形码分析的应用还处于起步阶段。随着分析方法的日趋成熟,可适用于不同应用领域的分子标记不断增加,以及参考数据库的不断完善,宏条形码分析将释放出广阔的应用潜力。可以预期,宏条形码分析将在系统分析我国近岸海域有害藻华物种（及其他浮游生物物种）的组成和相对丰度中起关键作用,通过发现新物种,辨别隐存种,跟踪物种的生物地理学,进而帮助解析有害藻华暴发机理。  相似文献   

东海赤潮高发区表层沉积物中部分脂类标记物的分布与来源   总被引：2，自引：1，他引：1  

褚宏大  苏荣国  王修林  王江涛  曹芳  卢璐 《海洋科学》2008,32(10):68-76

通过对2005年和2006年东海赤潮高发区表层沉积物部分脂类标记物（正构烷烃、脂肪酸等）的分析,初步探讨了表层沉积物有机物的来源。沉积物中正构烷烃的碳优势指数Icp值及姥鲛烷／植烷的质量比（Pr／Ph）普遍较低,而n-C16,n-C18的质量分数较高。分析表明,石油烃是东海赤潮高发区表层沉积物脂肪烃的主要成分。来源于细菌、海洋微藻和陆生高等植物的脂肪酸如直链饱和脂肪酸、支链饱和脂肪酸、不（多不）饱和脂肪酸等在2005～2006年间的组成和分布比较稳定：直链脂肪酸含量普遍较高,其次为支链脂肪酸和单不饱和脂肪酸,多不饱和脂肪酸含量相对较少。利用生物标记物分析表明,海洋自生生物源（细菌、海洋微藻等）是沉积物中脂肪酸的主要来源,陆源脂肪酸对东海赤潮高发区表层沉积物的贡献较小。  相似文献   

4种养殖扇贝的群体遗传多样性及特异性AFLP标记研究   总被引：27，自引：2，他引：27  

陈省平  包振民  潘洁  胡景杰 《海洋学报》2005,27(2):160-164

应用AFLP技术对我国4种主要养殖扇贝进行了遗传分析.虾夷扇贝、海湾扇贝、华贵栉孔扇贝、栉孔扇贝4种养殖扇贝群体中,种内遗传相似度依次分别为0.841 5,0.786 3,0.719 0和0.673 1,香侬氏指数分别为43.52,58.87,80.16和92.83,栉孔扇贝和华贵栉孔扇贝的遗传多样性水平明显高于海湾扇贝和虾夷扇贝;AFLP标记共享位点分布表明,在4种扇贝中栉孔扇贝与华贵栉孔扇贝之间的共享位点最多,同时4种扇贝的种间遗传相似度也以栉孔扇贝和华贵栉孔扇贝之间为最高(0.769 5),海湾扇贝和虾夷扇贝之间为最低(0.662 6),揭示所研究的几种扇贝中栉孔扇贝和华贵栉孔扇贝的遗传关系最近(遗传距离为0.262 1);找到了21个种内特异性AFLP标记和种间共享标记,可用于种质鉴定和分子辅助分类.  相似文献   

皱纹盘鲍杂交F₁代与亲本的RAPD标记及分离方式分析   总被引：8，自引：0，他引：8  

肖洁  刘晓  张国范  郭希明 《海洋学报》2004,26(6):124-132

应用RAPD标记技术对皱纹盘鲍杂交家系JC的双亲及3个F₁个体进行了分析,对JC家系在皱纹盘鲍遗传连锁图谱构建中的应用前景进行了初步评估,并分析了RAPD分子标记在JC家系F₁代中的分离方式及该家系的1对亲本及其子代个体的遗传结构.7条随机引物共扩增出41个分子标记,其中24个为多态性,占总数的58.5%;有14个分离标记可用于遗传连锁作图,有7个符合孟德尔独立分配定律,占总数的17.1%.2个标记与子代个体大小有一定的相关性,但其连锁关系仍有待于进一步研究.父母本之间的遗传距离为0.384 4,父本与子代间的距离为0.137 2,母本与子代间的距离为0.127 3;父本提供的分离标记在子代中的显性频率为0.47,母本为0.55.双亲之间的遗传距离较远,杂交产生的JC-F₁群体具有较高的杂合度(0.201 6),该结果初步表明皱纹盘鲍杂交家系JC的子1代即可作为作图群体应用于皱纹盘鲍的连锁图谱构建.  相似文献   

不同地理品系卤虫的同工酶变异初步研究   总被引：1，自引：1，他引：1  

高明君  葛兰  蔡亚能 《中国海洋大学学报(自然科学版)》1994,(1)

利用聚丙烯酰胺凝胶电泳方法，对国内外不同生态地区的孤雌生殖和两性生殖卤虫进行了酯酶（ＥＳＴ）、四唑氧化酶（ＴＯ）和碱性磷酸酶（ＡＬＰ）同工酶变异分析。指出不同地理品系卤虫有其独特的ＥＳＴ和ＴＯ标志酶带；孤雌生殖卤虫具有与两性生殖卤虫显著不同的ＴＯ基本带型和ＡＬＰ标志带区。这些结果为卤虫地理品系的纯度鉴定，以及两种生殖方式卤虫的分类和鉴别提供了生化指标。  相似文献   

若干恒星形成区的^12CO（J=1—0）与^13CO（J=1—0）观测   总被引：1，自引：0，他引：1  

毛瑞青  韩溥 《紫金山天文台台刊》1997,16(2):69-76

首次利用紫金山天文台青海观测站13.7m毫米波射电望远镜对若干分子云与恒星形成区的~(12)CO(J=1—0)和~(13)CO(J=1—0)分子辐射进行了观测,得到了各自中心位置的谱线轮廓。作为一个实例本文将介绍如何通过对分子云~(12)CO(J=1—0)和~(13)CO(J=1—0)谱线的综合分析与计算得到云中的物理参数。  相似文献   

A possible new molecular mechanism of thundercloud electrification   总被引：1，自引：1，他引：1  

Pavel Jungwirth  Daniel Rosenfeld  Victoria Buch 《Atmospheric Research》2005,76(1-4):190

Thunderclouds are electrified when charge is transferred between small and large ice particles colliding in a cloud that contains strong updrafts. The small ice particles rise with one type of charge and the large ice particles fall and carry with them downward the other type of charge, which is most often negative, so that normally lightning lowers negative charge from cloud to the ground. While the collisional mechanism of thundercloud charging is well established, the nature of the charge transfer between the colliding ice particles is not very well understood on the atomic level, and no present theory can explain it in full detail. Here we propose a new charge separation mechanism that is based on molecular dynamics simulations of particle surfaces and collisions, keeping track of the individual charges as they move in the form of salt ions from one ice particle to another. Under normal conditions, when sulfates dominate as cloud condensation nuclei, this ionic mechanism is consistent with the prevailing negative charging of graupels in thunderclouds. Moreover, with dearth of sulfate anions, the present mechanism predicts a shift towards positive charging. This fits well to a large range of observations of enhanced positive lightning, connected with smoke rich in chlorides and nitrates, that could not be explained satisfactorily previously.  相似文献   

A novel high-resolution small ion spectrometer to study ion nucleation of aerosols in ambient indoor and outdoor air     

A.P. Fews  N.K. Holden  P.A. Keitch  D.L. Henshaw 《Atmospheric Research》2005,76(1-4):29

An electrically based ion spectrometer is described, capable of measuring particle sizes and mobilities from molecular ions (small ions) to aerosol particles across a size range of 0.4 to 30 nm in diameter. It consists of a single cylindrical capacitor divided into three electrically insulated sections. The current arriving at the central section is measured by an electrometer and represents the ion flux over a known range of mobilities determined by the applied voltage. The applied voltage is scanned in steps to measure the ion fluxes over a large number of overlapping mobility ranges. The recorded signal and the response function of the instrument are unfolded using a maximum entropy procedure to give a high-resolution measured mobility spectrum. The maximum entropy approach offers a considerable improvement over traditional aspiration collectors and can approach the resolution of a drift tube system. In this way, the spectrometer successfully overcomes the diffusion limit to small ion resolution. Illustrative spectra are shown, demonstrating for the first time the presence of some resolved structure within the small ion spectrum at the highest mobilities. It is demonstrated that the actual mobility spectrum of small ions falls in the range 0.8–2.0 × 10⁻⁴ m² V⁻¹ s⁻¹. This represents a narrower range than that previously measured which is attributed to improved spectral resolution in the present work.  相似文献   

The La Luna formation: chemostratigraphy and organic facies in the Middle Magdalena Basin     

A. Rangel  P. Parra  C. Nio 《Organic Geochemistry》2000,31(12):2694

A detailed geochemical study and a sequence stratigraphic interpretation have been conducted on a sedimentary sequence of the Upper Cretaceous La Luna Formation, in a section outcropping in the eastern flank of the Middle Magdalena Basin (MMB), Colombia. The goals were to evaluate geochemical variability related to lithofacies and organic facies changes, characterize depositional environment and investigate the possible relationship between geochemical data and sequence stratigraphic cycles. The La Luna Formation is composed of organic-rich sediments of monotonous appearance, with good to excellent potential for oil generation. Most of the bulk, petrographic and biomarker parameters display a relatively narrow range of variation. However, the geochemical variations are sufficient to differentiate organic facies types B, BC and C in the Salada Member, B and D in the Pujamana Member and B in the Galembo Member. Certain biomarker ratios are consistent within the La Luna Formation and are characteristic of its depositional environment, for example, average ratios of diasterane/sterane are lower than 1, Ts/Tm averages are less than 0.33, the C₃₅/C₃₄ hopane ratio is more than 0.92, and oleanane/C₃₀ hopane ratios range from 0.02 to 0.19. Regarding depositional condition indicators, the C₃₅/C₃₄ hopane ratio shows a good positive correlation with HI. This suggests that in carbonate environment changes in this parameter are more strongly related to redox condition than to changes in carbonate content. Regarding the possible relationship between organic matter characteristics and sea level changes, in regressive carbonate shelves during shallow stages, HI tends to increase and TOC tends to decrease, while in regressive siliciclastic shelves, both TOC and HI decrease continuously. Some biomarker ratios (oleanane/C₃₀ hopane, C₂₀/C₂₃ tricyclic, Ts/Tm) increase during base level falls. Regarding δ ¹³C/¹²C isotope composition, the aromatic fraction and whole bitumen display an isotopic shift associated to the main deepening event in the section.  相似文献