东北亚地区Ms5.0以上地震前后空间电场时空演化特征研究     

杨牧萍  张学民  泽仁志玛  申旭辉  黄建平  钱庚  金艳铭  黄明威 《地震》2021,41(4):78-92

本文利用2005年1月—2009年12月DEMETER电磁卫星观测的极低频/甚低频(ELF/VLF)39 Hz~6 kHz频段电场功率谱密度(PSD)观测量, 将研究频段划分为5个子频段对东北亚地区(38°N~58°N; 105°E~145°E)内发生的8个M_S≥5.0地震前后空间电场时空演化特征进行研究。 研究发现同一地震不同频段异常扰动区域并不完全在同一位置, 且同一地震的不同频段地震前后扰动形态也并不一致; 8个地震40次统计中有25% 的统计数据虽然基本在地震前后所有时间段都超过阈值2σ, 但未见明显扰动规律, 其余75%的统计数据中发现其扰动特征可以归纳为3类: 52%的统计数据在震前扰动幅度增大, 达到最大时发震, 震后持续降低; 7.5%的统计数据在震前扰动幅度达到高值, 而后下降过程中发震; 15%的统计数据在震前扰动幅度一直在增加且绝大部分时间低于2σ, 直至震后超过2σ, 且出现这种类型的异常均为震例的第五频段演化特征。 异常扰动区域主要集中在震中±4°以外的区域。  相似文献   

Error analyses of CHAMP data for recovery of the Earth’s gravity field   总被引：1，自引：0，他引：1  

P. Moore  J.F. Turner  Z. Qiang 《Journal of Geodesy》2003,77(7-8):369-380

A preliminary commission error analysis whereby orbit perturbation theory and other techniques are used to assess and predict the recovery of the Earths gravity field from the challenging microsatellite payload (CHAMP) mission is developed and implemented. With CHAMP launched in July 2000, accumulated evidence is now available to quantify the errors in the recovery procedure including the orbital precision from GPS, attitude errors, accelerometer noise and thruster mismatch/misalignment. For the latter, numerical integrations using a variable length single-step Runge–Kutta integrator and a fixed length multi-step method are compared to assess the error associated with assuming that the thruster misalignment can be spread uniformly across a step interval. Error degree variances from simulated studies are compared to results from a recently released CHAMP-based gravity field, EIGEN-1S. It is seen that the orbital positioning, as derived from the onboard GPS receiver, is critical, with accelerometer noise contributing at a lower level. Attitude error, at currently quoted accuracy, is not significant as an error source. AcknowledgementsThe authors would like to thank the UK Natural Environment Research Council (Grant No. NER/A/0000/00612) for financing this study and GFZ for supplying the data and technical support.  相似文献   

Isolation and characterization of 49 polymorphic microsatellite loci for Decapterus maruadsi using SLAF-seq,and cross-amplifi cation to related species     

NIU Sufang  ZHAI Yun  WU Renxie  ZHANG Haoran  TIAN Letian  DENG Jiaxin  XIAO Yao 《海洋湖沼学报（英文）》2019,(1):245-255

Decapterus maruadsi is a commercially important species in China, but has been heavily exploited in some areas. There is a growing need to develop microsatellites promoting its genetic research for the adequate management of this ?shery resources. The recently developed speci?c-locus ampli?ed fragment sequencing(SLAF-seq) is an effcient and high-resolution method for genome-wide microsatellite markers discovery. In this study, 28 905 microsatellites(mono-to hexa-nucleotide repeats) were identi?ed using SLAF-seq technology, of which di-nucleotide was the most frequent(13 590, 47.02%), followed by mono-nucleotide(8 138, 28.15%), tri-nucleotide(5 727, 19.81%), tetra-nucleotide(1 104, 3.82%), pentanucleotide(234, 0.81%), and hexa-nucleotide(112, 0.39%). One hundred and thirty-two microsatellite loci(di-and tri-nucleotide) were randomly selected for ampli?cation and polymorphism, of which 49 were highly polymorphic and well-resolved. The average number of alleles per locus was 13.63, ranging from 4 to 25, and allele sizes varied between 110 bp and 309 bp. The observed heterozygosity( Ho) and expected heterozygosity( He) ranged from 0.233 to 1.000 and from 0.374 to 0.959, with mean values of 0.738 and0.836, respectively. The polymorphism information content(PIC) ranged from 0.341 to 0.941(mean=0.806).However, 12 loci deviated from Hardy-Weinberg equilibrium. Furthermore, transferability tests were also successful in validating the utility of the developed markers in ?ve phylogenetically related species of family Carangidae. A total of 48 microsatellite markers were successfully cross-ampli?ed in Decapterus macarellus, Decapterus macrosoma, Decapterus kurroides, Trachurus japonicus, and Selaroides leptolepis.The present microsatellites provided the ?rst known set of microsatellite DNA markers for D. maruadsi,D. macarellus, D. kurroides, and D. macrosoma, and would be useful for further population genetic and molecular phylogeny studies as well as help with the ?sheries management formulation and implementation of the understudied species.  相似文献   

Isolation and characterization of genic microsatellites from de novo assembly transcriptome in the bivalve Ruditapes philippinarum     

SHANGGUAN Jingbo  XU Anle  HU Xiaowei  LI Zhongbao 《海洋湖沼学报（英文）》2019,(3):1071-1079

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长牡蛎(Crassostrea gigas)多代近交与自交家系遗传差异及生长性状比较     

任晶莹  王卫军  徐涛  赵强  李彬  孙国华  杨建敏 《海洋与湖沼》2018,49(3):630-637

在良种选育过程中,为了尽快得到稳定可遗传的优良性状,常采用近交方式进行纯系选育,而近交会导致群体的遗传多样性下降。为了解长牡蛎(Crassostrea gigas)多代近交和自交家系的遗传多样性、遗传结构和生长情况,本实验选用长牡蛎近交4代(F4代)、近交5代(F5代)家系和雌性同体自交1代(自交1代)家系,采用8对多态性高的微卫星序列进行分析,同时对其成体的三个时间点生长数据进行了显著性差异分析。实验结果表明,8对微卫星位点在野生对照组中表现出较高的多态性,F4代、F5代和自交1代3个家系的遗传多样性明显下降,平均等位基因数(Na)由17.00下降到2.00,平均观测杂合度(Ho)由0.538下降到0.449,平均多态信息含量(PIC)由0.826下降到0.297;哈迪-温伯格平衡(HWE)检验结果显示,8个位点在三个家系和野生对照组中均不同程度偏离HWE平衡(P0.0062)。F4代、F5代、自交1代和野生对照的生长性状指标分析表明,和野生对照相比,三个家系生长指标明显提高,对于自交一代而言,与自交实验组亲本选择的偶然性有关。同时,三个家系三个时间点的壳长、壳宽生长性状没有显著性差异(除330日龄壳宽和630日龄壳长),F5代生长性状指标壳高和湿重均大于F4代和自交1代,且差异显著;但F4代和自交1代之间没有显著性差异。通过本研究发现,F5代可以继续用来进行生长性状新品系的选育,自交1代多样性降低程度相当于F5代,但多样性的降低对成体的生长性状影响不明显,仍可以用做相关实验材料。  相似文献   

许氏平鲉(Sebastes schlegelii)速生选育群体的生长性能与遗传特征分析     

刘阳  韩慧宗  王腾腾  孙娜  张明亮  王斐  冯艳微  杜荣斌  姜海滨 《海洋与湖沼》2018,49(2):432-443

本研究目的为开展许氏平鲉(Sebastes schlegelii)遗传改良和优质新品系选育,选取荣成(R)和长岛(C)的野生许氏平鲉为基础群体,采用群体选育(群体内和群体间)和家系选育相结合的方法,获得R-F1、RC-F1两个群体选育群体和R-F2、RC-F2、R-F3、RC-F3四个家系选育群体。对4个选育家系的生长性能进行比较分析,并利用20对高多态性的微卫星标记对8个群体进行遗传多样性检测。结果表明:(1)群体内和群体间家系选育子3代比家系选育子2代生长速度分别提高21.59%和30.99%。4个选育家系后代的绝对增重率随着天数的增加而上升,群体内家系选育(R-F3)的生长速度、绝对增重率显著大于群体间的杂交选育系(RC-F3),杂交系未表现出生长的杂种优势。(2)20对微卫星位点在所有群体中均表现出较高多态性,8个群体的平均有效等位基因数(Νe)为2.9849—7.9598,平均观测杂合度(oH)和期望杂合度(He)分别为0.7230—0.8405和0.6315—0.8716,平均多态信息含量(PIC)为0.6472—0.8478。经两代家系选育的R-F3和RC-F3平均等位基因数显著降低,但观测杂合度(Ho)和期望杂合度(He)均值仍达到0.7230、0.7549和0.6527、0.6315,还有维持了较高的遗传多样性水平,遗传潜力较大。Hardy-Weinberg平衡检测结果和遗传偏离指数(d)表明各群体在大约10个位点上表现出一定程度的杂合子缺失现象。群体间平均遗传分化系数(Fst)为0.1279,各群体间存在中等遗传分化程度。R与R-F1分别与RC-F3遗传距离最远(0.9959、0.9848),预测利用两组群体中生长优良个体分别进行杂交育种有可能获得杂种优势。  相似文献   

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   

Microsatellite DNA polymorphisms and the relation with body weight in sea cucumber Apostichopus japonicus     

WANG Xiuli  SHAN Xue  QIU Xuemei  MENG Xiangying  CHANG Yaqing 《中国海洋湖沼学报》2009,27(2)

The relationship between microsatellite polymorphism and body weight of captive bred Chinese sea cucumber Apostichopus japonicus was investigated in two local populations in Dalian.Among ten loci discovered, nine show changes except for A J07 loci. Seven loci were found highly polymorphic in both populations. For each locus in two populations, the average number of alleles is 6.428 6 and 6.285 7, the average observed heterozygosity at 0.225 7 and 0.245 9, the expected heterozygosity at 0.776 8 and 0.748 8, the polymorphism information content (PIC) at 0.709 2 and 0.674 6, respectively. Further analysis show significant correlation between A. japonicus body weight and occurrence markers AJ02 and AJ04. The findings of the relation may be helpful for molecular breeding,as well as the marker-assisted selection of sea cucumbers.  相似文献   

马氏珠母贝微卫星快速分离及遗传多样性分析   总被引：8，自引：0，他引：8  

佟广香  闫学春  匡友谊  梁利群  孙效文  王爱民  王嫣 《海洋学报》2007,29(4):170-176

马氏珠母贝(Pinctada martensii Dunker)又称合浦珠母贝,是世界上用于生产海水珍珠的最主要贝类之一.自60年代我国成功地开展马氏珠母贝的人工育苗以来,海水珍珠养殖业发展迅速,至20世纪90年代,海水珍珠养殖已成为广东、广西和海南沿海部分地区的支柱产业,海水珍珠成为出口创汇的重要产品.海水珍珠产业的发展仅靠采捕天然野生的亲贝已不能满足生产的需要,越来越多地用人工养殖的亲贝进行人工繁殖.而采用少数亲贝(尤其是养殖亲贝)的育苗导致近亲繁殖,使马氏珠母贝种质资源出现了退化,在海水珍珠养殖上产生的直接后果是珍珠的质量和产量(单产)明显下降.  相似文献   

微卫星DNA标记技术及其在海洋生物遗传学中的应用   总被引：3，自引：0，他引：3  

胡则辉  周志刚 《海洋湖沼通报》2006,(1):37-45

DNA简单重复序列从1974年在海洋生物中被发现,到1989年“微卫星”术语开始使用这段时间是这种新型分子标记技术的发展阶段。伴随着PCR技术的发明、成熟与拓展,微卫星DNA以其多态性高、随机分布、共显性遗传、重复性好等特点在生物学的个体及系统发育方面得到很广泛的应用。本文从微卫星DNA的发展简史开始,较详细地介绍了它的原理、方法及策略,然后概括了在海洋动、植物的遗传学中,微卫星DNA在遗传多样性分析、遗传图谱构建、基因鉴定和标记以及系谱认证等领域的研究,展望了其在海洋生物分子育种、基因克隆、生物保护等方面的应用前景。  相似文献