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1.
本文阐述了形态测量学中一类重要的研究方法——轮廓形态测量法的基本概念和发展,总结了轮廓形态测量法在生物分类学研究中的应用,将轮廓形态测量法与另一类重要的形态测量学方法——标点法进行了比较,分析了这两类方法各自的优势和局限性,展望了轮廓形态测量法在昆虫分类学研究中的应用前景。  相似文献   

2.
几何形态测量方法是生物学研究中用于形态特征分析和形态比较研究的一种常用方法。其核心思想是利用空间坐标点获取研究对象的形态数据,再通过坐标数据的多元统计分析,定量探讨研究对象的形态特征及影响其形态变异的因素。近年来,随着三维扫描技术的广泛应用以及对于石制品形态特征量化分析要求的提高,基于三维模型的几何形态测量方法开始出现在相关的旧石器考古研究中。本文首先对三维几何形态测量分析方法及其在石制品研究中的应用情况进行介绍,随后具体阐述了该方法的分析流程。为便于国内学者更好地了解这一方法,本文进一步以广西百色盆地南坡山遗址发现的手斧为例,利用三维几何形态测量方法对这些手斧的几何形态特征进行了初步探讨。三维几何形态测量方法为石制品形态研究提供了新思路和新视角,有望成为今后中国旧石器考古研究中一个重要的发展方向。  相似文献   

3.
湖泊水体形态是景观空间的重要组成部分,以往对于湖泊景观水体形态的研究多囿于定性描述,本文引入了定量方法对城市湖泊景观的水体形态展开研究,采用基本几何、分形几何与欧式几何形态指标对水体形态进行描述,以28个公众认可度高的城市湖泊为案例,通过定量评价得到水体形态指标数值或区间,并基于线性回归分析,探讨了各个指标之间的影响及关联,解析归纳了湖泊景观水体的“形态”特征。  相似文献   

4.
几何形态计量学在昆虫自动鉴定中的应用与展望   总被引:1,自引:0,他引:1  
几何形态计量学着重研究的是生物形态的拓扑结构信息,不受标本大小和形状变化的影响,是进行昆虫自动鉴定的一个新的手段。本文首先介绍了传统形态计量学和几何形态计量学两种昆虫自动鉴定的方法,并着重介绍了轮廓分析法和标志点分析法等几何形态计量学的分析方法,以及目前开发的几何形态计量学昆虫自动鉴定软件,简述了该方法应用于昆虫自动鉴定的工作流程,最后对几何形态计量学在昆虫自动鉴定方面的未来发展进行了展望。  相似文献   

5.
本文综述了近年来植物对磷营养高效吸收有关的根系形态方面的研究进展, 总结了植物适应低磷胁迫的根系形态特征, 以及植物适应低磷胁迫根系形态变化的激素调控的内在机制, 着重阐述了植物适应低磷根系形态变化的分子生物学基础, 并对开展此类工作的有效途径进行了探讨。  相似文献   

6.
若干悬钩子属植物的花粉形态研究   总被引:7,自引:0,他引:7  
陈少风  叶居新 《植物研究》1996,16(4):463-466
蔷微科悬钩子属10种植物的花粉形态进行了扫描电镜观察,描述了花粉形态的特征,探讨了植物花粉形态特征与外部形态特征的关系。  相似文献   

7.
浙江杜鹃花属植物种子形态及其分类学意义   总被引:10,自引:0,他引:10  
本文对浙江产杜鹃花属13个种(录属5个亚属7个组)的种子形态进行了研究。比较观察了种子形状、大小、扁化率,翅和表面结构等形态学特征,井对该属种子形态的演化趋势、种于类型的划分及种子形态在分类学上的意义进行了讨论。结果表明种子形态特征与植物习性和形态特征一定程度上相关,反映了周内类群的分化,因而种子形态在杜鹃花属的系统研究中是不可忽视的性状。  相似文献   

8.
土壤中砷的形态转化及其分析方法   总被引:8,自引:0,他引:8  
和秋红  曾希柏 《应用生态学报》2008,19(12):2763-2768
在分析土壤中砷的来源及存在形态的基础上,简要探讨了不同形态砷之间相互转化的过程.对土壤砷形态的提取和检测方法进行了较系统的比较,认为高效液相色谱-氢化物发生-原子荧光光谱(HPLC-HG-AFS)联用技术具有灵敏度高、检测限低、选择性强、运行成本低、不同形态砷之间相互转化较少的优点,可以作为砷形态检测的首选方法.结合相关研究结果,对土壤中砷形态转化及相关研究的发展方向进行了讨论.  相似文献   

9.
干旱区叶片形态特征与植物响应和适应的关系   总被引:7,自引:0,他引:7       下载免费PDF全文
叶片形态是指示植物适应特定环境的重要指标。由于植物叶片形态不仅对时空环境变化具有极强的敏感性和可塑性, 而且能够通过叶片形态的调整调节自身的生存适应能力, 所以叶片形态学研究一直是植物生理及植物生态学研究中的热点。该文在总结前人叶片形态学研究成果的基础上, 探索建立了简单的叶片形态指标分类体系; 结合物质能量交换的物理学原理, 回顾总结了叶片表观形态变化与叶片物质能量交换之间的相关关系; 应用叶片形态影响物质能量交换的物理学原理, 重点分析了干旱区植物叶片表观形态对低水分环境、高辐射(或高温)的响应与适应特征; 最后, 在回顾分析的基础上, 对叶片形态研究中存在的几个问题进行了讨论。  相似文献   

10.
丝状真菌(Filamentous fungi)的发酵生产通常具有较高的工业应用价值,但其菌体形态是一个区别于其他非丝状菌的一个重要发酵指标。针对目前形态分析的瓶颈,本研究使用琼脂糖凝胶对黑曲霉菌形进行固定,利用平板实现菌球样本的大量制备,并结合图形处理软件自建自动化处理程序,实现了大量准确可靠的菌体形态参数的获得,大大增加了形态数据处理通量及准确度。应用该方法于黑曲霉发酵生产糖化酶过程中不同供氧水平及剪切水平下菌体形态的研究,通过大量形态数据定量阐明了黑曲霉在不同剪切水平下的分区域形态分布特性,为进一步工业过程的形态优化提供了重要的研究方法。  相似文献   

11.
12.
Truffle trouble: what happened to the Tuberales?   总被引:1,自引:1,他引:0  
An overview of truffles (now considered to belong in the Pezizales, but formerly treated in the Tuberales) is presented, including a discussion on morphological and biological traits characterizing this form group. Accepted genera are listed and discussed according to a system based on molecular results combined with morphological characters. Phylogenetic analyses of LSU rDNA sequences from 55 hypogeous and 139 epigeous taxa of Pezizales were performed to examine their relationships. Parsimony, ML, and Bayesian analyses of these sequences indicate that the truffles studied represent at least 15 independent lineages within the Pezizales. Sequences from hypogeous representatives referred to the following families and genera were analysed: DiscinaceaeMorchellaceae (Fischerula, Hydnotrya, Leucangium), Helvellaceae (Balsamia and Barssia), Pezizaceae (Amylascus, Cazia, Eremiomyces, Hydnotryopsis, Kaliharituber, Mattirolomyces, Pachyphloeus, Peziza, Ruhlandiella, Stephensia, Terfezia, and Tirmania), Pyronemataceae (Genea, Geopora, Paurocotylis, and Stephensia) and Tuberaceae (Choiromyces, Dingleya, Labyrinthomyces, Reddellomyces, and Tuber). The different types of hypogeous ascomata were found within most major evolutionary lines often nesting close to apothecial species. Although the Pezizaceae traditionally have been defined mainly on the presence of amyloid reactions of the ascus wall several truffles appear to have lost this character. The value of the number of nuclei in mature ascospores as a delimiting family character is evaluated and found to be more variable than generally assumed.  相似文献   

13.
A molecular phylogeny of Hebeloma species from Europe   总被引:2,自引:1,他引:1  
In order to widen the scope of existing phylogenies of the ectomycorrhizal agaric genus Hebeloma a total of 53 new rDNA ITS sequences from that genus was generated, augmented by sequences retrieved from GenBank, and analysed using Bayesian, strict consensus and neighbour joining methods. The lignicolous Hebelomina neerlandica, Gymnopilus penetrans, and two species of Galerina served as outgroup taxa. Anamika indica, as well as representatives of the genera Hymenogaster and Naucoria, were included to test the monophyly of Hebeloma, which is confirmed by the results. Hebeloma, Naucoria, Hymenogaster and Anamika indica cluster in a strongly supported monophyletic hebelomatoid clade. All trees largely reflect the current infrageneric classification within Hebeloma, and divide the genus into mostly well-supported monophyletic groups surrounding H. crustuliniforme, H. velutipes, H. sacchariolens, H. sinapizans, and H. radicosum, with H. sarcophyllum being shown at an independent position; however this is not well supported. The section Indusiata divides with strong support into three groups, the position of the pleurocystidiate Hebeloma cistophilum suggests the possible existence of a third subsection within sect. Indusiata. Subsection Sacchariolentia is raised to the rank of section.  相似文献   

14.
Phylogenetic relationships within the angiosperm orderCampanulales were investigated by comparative sequencing of the chloroplast generbcL. CompleterbcL sequences were obtained for ten species in six families within the order. These data were analyzed along with previously publishedrbcL sequences from other taxa (for a total of 117 species) within the subclassAsteridae and outgroups, producing 32 equally parsimonious trees. A subset consisting of 44 of these taxa was then chosen and more rigorous analyses performed, resulting in four equally parsimonious trees. Results indicate that two major clades roughly corresponding to traditionally circumscribedAsterales andCampanulales exist as sister taxa. In particular, therbcL trees indicate thatSphenoclea is not a member ofCampanulales orAsterales, thatPentaphragma is more closely allied toAsterales thanCampanulales, that theCyphiaceae are not monophyletic, thatCampanulaceae andLobeliaceae are not sister taxa, and thatStylidiaceae are correctly placed withinCampanulales.  相似文献   

15.
The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.  相似文献   

16.
The family Sordariaceae incorporates a number of fungi that are excellent model organisms for various biological, biochemical, ecological, genetic and evolutionary studies. To determine the evolutionary relationships within this group and their respective phylogenetic placements, multiple-gene sequences (partial nuclear 28S ribosomal DNA, nuclear ITS ribosomal DNA and partial nuclear β-tubulin) were analysed using maximum parsimony and Bayesian analyses. Analyses of different gene datasets were performed individually and then combined to generate phylogenies. We report that Sordariaceae, with the exclusion Apodus and Diplogelasinospora, is a monophyletic group. Apodus and Diplogelasinospora are related to Lasiosphaeriaceae. Multiple gene analyses suggest that the spore sheath is not a phylogenetically significant character to segregate Asordaria from Sordaria. Smooth-spored Sordaria species (including so-called Asordaria species) constitute a natural group. Asordaria is therefore congeneric with Sordaria. Anixiella species nested among Gelasinospora species, providing further evidence that non-ostiolate ascomata have evolved from ostiolate ascomata on several independent occasions. This study agrees with previous studies that show heterothallic Neurospora species to be monophyletic, but that homothallic ones may have a multiple origins. Although Gelasinospora and Neurospora are closely related and not resolved as monophyletic groups, there is insufficient evidence to place currently accepted Gelasinospora and Neurospora species into the same genus.  相似文献   

17.
The serological reaction of seed proteins provides evidence for a partly new systematic arrangement ofCytisus sect.Trianthocytisus and ofCytisus s.l. Proposed modifications agree with recent advances in morphological taxonomy. Sect.Trianthocytisus includes only two species,C. villosus andC. aeolicus. Its position is central within the genus, and this fact agrees with the proposed retypification ofCytisus (type species:C. villosus).C. emeriflorus, formerly included in the same section, constitutes the monospecific sect.Emeroides, which is intermediate towards the genusLembotropis. This is serologically isolated and includes onlyL. nigricans. It is confirmed thatC. sessilifolius should be removed from the genusCytisus as a monospecific genus:Cytisophyllum Lang which is closely allied toHesperolaburnum and toPodocytisus, the most primitive genera ofGenisteae.  相似文献   

18.
The taxonomic positions ofRetzia, Desfontainia, andNicodemia have been much discussed, and all three genera have been included inLoganiaceae (Gentianales). We have made a cladistic analysis ofrbcL gene sequences to determine the relationships of these taxa toGentianales. Four newrbcL sequences are presented; i.e., ofRetzia, Desfontainia, Diervilla (Caprifoliaceae), andEuthystachys (Stilbaceae). Our results show thatRetzia, Desfontainia, andNicodemia are not closely related toLoganiaceae or theGentianales. Retzia is most closely related toEuthystachys and is better included inStilbaceae. The positions ofDesfontainia andNicodemia are not settled, butDesfontainia shows affinity for theDipsacales s.l. andNicodemia for theLamiales s.l.  相似文献   

19.
TherbcL gene of 25 taxa was sequenced and analyzed cladistically in order to define more precisely the orderAsterales s.l. and to reconstruct the phylogeny ofGoodeniaceae. The cladistic analyses show that theAsterales comprise the familiesAbrophyllaceae, Alseuosmiaceae, Argophyllaceae, Asteraceae, Calyceraceae, Campanulaceae s.l.,Donatiaceae, Goodeniaceae (includingBrunoniaceae),Menyanthaceae, Pentaphragmataceae, andStylidiaceae. Abrophyllaceae, Alseuosmiaceae, Brunoniaceae, andDonatiaceae have previously not been studied in this respect. Within theGoodeniaceae, four groups supported by therbcL data can be distinguished: the genusLechenaultia, theAnthotium-Dampiera-group, the genusBrunonia, and a group formed by the remaining genera, theScaevola-Goodenia-group.  相似文献   

20.
The genusKarschia, in the earlier sense, including saprophytes and parasites on lichens, has been thought to be a non-lichenized parallel genus of the lichen genusBuellia. Modern workers included it on the one hand inBuellia, on the other hand combined it with bitunicate ascomycetes. It is now proved thatKarschia is heterogeneous and contains but superficially similar members both of the genusBuellia of theLecanorales and of typical or masked bitunicateAscomycetes. Therefore, it can not be regarded as a link betweenLecanorales andDothideales. The type species ofKarschia belongs to theDothideales.
  相似文献   

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