搜索结果: 151-165 共查到“生物学 系统发育”相关记录289条 . 查询时间(0.245 秒)
基于齿体特征的小车轮虫属系统发育研究
量化法 齿体 小车轮虫属 亲缘关系
2009/8/27
附着盘上的齿体结构是车轮虫物种鉴定的一个重要特征,本文依据齿体特征量化值,分析探讨了小车轮虫间的亲缘关系。首先对所收集的1种壶形虫和5种小车轮虫:趾核壶形虫Urceolaria karyodactyla、波罗的海小车轮虫Trichodinella baltica、卡普小车轮虫Trichodinella carpi、流行小车轮虫Trichodinella epizootica、劳牧小车轮虫Trich...
首次测定、分析了七种海洋纤毛虫(固着目、缘毛亚纲:团结蛤表单缩虫、拟杯状伪钟虫、糙面伪钟虫、倪氏聚缩虫、交替聚缩虫、羽状聚缩虫、中华拟聚缩虫)的rRNA转录间隔区-5.8S rRNA基因(ITS1-5.8S-ITS2)序列。结果显示:七种纤毛虫的5.8S区序列遗传相似度为0.9102—0.9811。ITS1和ITS2区的序列变异性大于5.8S区,遗传相似度分别为0.4201—0.9293,0.51...
线粒体D-loop序列变异与东方鲀属鱼类系统发育
系统发育 D-loop 东方鲀属
2009/8/26
东方鲀属的红鳍东方鲀(Takifugu rubripes)是后基因组时代的一种重要模式生物。本研究中,利用东方鲀属11种鱼类(18尾)的D-loop基因序列,对东方鲀属鱼类的系统发育关系进行研究。经序列比对排定后,分析中D-loop序列有841个位点,其中395个位点为可变位点,267个位点为系统发育信息位点。分别采用邻接法(NJ)、最大简约法(MP)、最大似然法(ML)和贝叶斯方法构建了分子系统...
Paranepheliinae亚族(菊科, Liabeae族)的系统发育和可能的属间杂交
Andes Asteraceae biogeography hybridization ITS sequences Liabeae Paranepheliinae Peru speciation trnL-trnF
2009/8/4
The nuclear ribosomal ITS region and the chloroplast trnL-trnF (trnLF) intergenic region were sequenced for 45 accessions of Paranephelius and six accessions of Pseudonoseris, the two genera of the su...
动物系统发育和大规模测序:进展和问题
long-branch attraction (LBA) artifact new animal phylogeny phylogenomics random error systematic error
2009/8/4
Phylogenomics, the inference of phylogenetic trees using genome-scale data, is becoming the rule for resolving difficult parts of the tree of life. Its promise resides in the large amount of informati...
《中国植物志》依照恩格勒系统, 将芸香科Rutaceae中的芸香亚科Rutoideae及飞龙掌血亚科Toddalioideae分列为两个亚科, 但形态及化学比较的结论支持将这两个亚科合并为芸香亚科Rutoideae; 而分子系统研究结果亦进一步支持合并, 并显示我国的吴茱萸属Euodia品种应按Hartley的处理, 分别置于吴茱萸属Tetradium和蜜茱萸属Melicope。另一方面, 九里香...
随着越来越多的基因序列被运用于系统发育重建中, 随之产生的基因树冲突已成为分子系统发育研究中日益突出的问题。因此, 在分子系统发育研究中, 应正确理解基因树和物种树之间的差异, 充分注意和分析基因树冲突的原因, 正确解释分子系统发育的结果。本文通过一些典型实例分析了在多基因系统发育研究中引发基因树冲突的三类主要原因: 随机误差、系统误差和生物学因素。在此基础上, 对近年来兴起的系统发育基因组学进...
虎耳草属山羊臭组的界定和系统发育: 核糖体DNA ITS序列证据
界定 ITS序列 系统发育 虎耳草属山羊臭组
2009/8/4
虎耳草属Saxifraga山羊臭组sect. Ciliatae是该属中最大的一个组, 共有175种, 主要分布在喜马拉雅地区, 我国分布有166种, 占总种数的95%; 其中, 112种为中国特有。约80%的种类分布在我国青藏高原和西南地区, 是中国喜马拉雅植物成分的代表类群。山羊臭组内物种分化十分显著, 分类处理也很困难, 该组是否为单系类群, 组下的系统发育关系也不清楚, 均需进一步验证。本...
果实类型和种子传播的进化:系统发育和生态学简论
adaptation angiosperm animal dispersal fruit development wind dispersal
2009/8/4
Success of flowering plants is greatly dependent on effective seed dispersal. Specific fruit types aid different mechanisms of seed dispersal. However, little is known about what evolutionary forces h...
根据叶绿体ndhF和核核糖体DNA序列推断梓属(紫葳科)的系统发育
Bignoniaceae Catalpa eastern Asia-North America ndhF gene nrDNA ITS sequences Phylogeny West Indies
2009/8/4
Phylogenetics of Chilopsis and Catalpa (Bignoniaceae) was elucidated based on sequences of chloroplast ndhF and the nrDNA ITS region. In Bignoniaceae, Chilopsis and Catalpa are most closely related as...
基于Rag1基因序列变异的鲤形目鱼类系统发育重建:采样策略对生命之树的影响
Cobitoidea Cypriniformes Cyprinoidea taxon sampling Tree of Life
2009/8/4
The phylogenetic relationships of species are fundamental to any biological investigation, including all evolutionary studies. Accurate inferences of sister group relationships provide the researcher ...
线蕨属Colysis植物主要分布于亚洲热带和亚热带地区, 少数种类分布至非洲、澳大利亚(昆士兰)及新几内亚地区。自1849年成立以来, 线蕨属的分类范畴和系统位置一直有待确定。本文利用叶绿体基因组的rbcL、rps4基因和rps4-trnS基因间隔区序列, 运用最大简约法和贝叶斯方法分析了线蕨属及其近缘类群的系统演化关系。研究结果显示: (1)线蕨属和薄唇蕨属Leptochilus (含似薄唇蕨属...
Sequences of the chloroplast ndhF gene and the nuclear ribosomal ITS regions are employed to reconstruct the phylogeny of Prunus (Rosaceae), and evaluate the classification schemes of this genus. The ...
类群取样与系统发育分析精确度之探索
consistency long-branch attraction phylogenetic accuracy phylogenomics systematic error taxon sampling Tree of Life
2009/8/4
Appropriate and extensive taxon sampling is one of the most important determinants of accurate phylogenetic estimation. In addition, accuracy of inferences about evolutionary processes obtained from p...
轮藻和陆地植物系统发育及其进化
charophytes evolution gravitropism land plants life cycle multicellularity origin phragmoplast phylogeny plasmodesmata the tree of life
2009/8/4
Charophytic algae and land plants together make up a monophyletic group, streptophytes, which represents one of the main lineages of multicellular eukaryotes and has contributed greatly to change of t...