多重PCR法检测对皮下和造血器官坏死杆状病毒

根据对虾皮下和造血坏死杆状病毒（ＨＨＮＢＶ）ＨＨＮＢＶ－ＸＩＡ靶基因序列设计了４个多重ＰＣＲ法用引物（Ｐ１、Ｐ２、Ｐ３、Ｐ４）。采用了五种引物组合形式分别对ＨＨＮＢＶ－ＸＩＡ、ＨＨＮＢＶ基因和ＰＲＤＶ－ＪＡＰＡＮ片段进行了物异扩增,建立了多重ＰＣＲ检测ＨＨＮＢＶ方法。通过优化多重ＰＣＲ法检测ＨＨＮＢＶ条件,可从阳性感染的中国对虾ｆｇ级ＤＮＡ中定性检测出皮下和造血器官坏死杆状病毒。     

丙型肝炎病毒RNA打点杂交检测方法同RT－PCR方法的比较

采用ＨＣＶ基因组结构区Ｃ区ｃＤＮＡ探针和非结构区ＮＳ３－４区ｃＤＮＡ探针,建立了用打点杂交（ｄｏｔｂｌｏｔｈｙｂｒｉｄｉｚａｔｉｏｎ）检测血清中ＨＣＶＲＮＡ的方法,同采用ＨＣＶ基因组５’端非编码区的一对寡核苷酸引物通过逆转录－聚合酶链式反应（ＲＴ－ＰＣＲ）检测血清中ＨＣＶＲＮＡ的方法相比较,发现两种方法都能快速早期和特异地检出血清中ＨＣＶＲＮＡ,但ＲＴ－ＰＣＲ法敏感性优于ＲＮＡ打点杂交法。对于无血清学指标的慢性ＮＡＮＢ肝炎病人的诊断,可采用这两种方法。这两种方法的敏感性在很大程度上依赖于引物和探针的敏感性,以及ＲＮＡ提取方法。ＲＴ－ＰＣＲ法适用于诊断病毒血症和复制,打点杂交法适用于研究ＨＣＶＲＮＡ量的变化,对治疗的评价,以及为实验筛选较高滴度的ＨＣＶＲＮＡ阳性样本。     

植被制图学进展

植被制图学进展潘代远（中国科学院植物研究所,北京,１０００４４）ＴＨＥＡＤＶＡＮＣＥＳＩＮＶＥＧＥＴＡＴＩＯＮＭＡＰＰＩＮＧ￥ＰａｎＤａｉ－ｙｕａｎ（ＩｎｓｔｉｔｕｅｏｆＢｏｔａｎｙ,ＡｃａｄｅｍｉａＳｉｎｉｃａ,Ｂｅｉｊｉｎｇ１０００４４）植被制图...     

鼻咽癌中Epetein－Barr病毒基因结构特点

鼻咽癌中感染的ＥＢＶ以潜伏态存在,只有少数基因得到表达。我们从分子生物学水平研究其潜伏机制。已知ＢＺＬＦｌ基因和ＢａｍＨＩＥＺ片段内部分基因对ＥＢＶ的复制激活起关键作用。我们用体外基因扩增（ＰＣＲ）法扩增ＢＺＬＦｌ基因外显子－１序列,并用序列分析法研究了该基因结构特点。此外,检测了ＢａｍＨＩＥＺ片段内缺失,结果发现２１例鼻咽癌（ＮＰＣ）组织中,ｌｌ例有ＢａｍＨＩＥＺ片段内缺失,长２．９９ｋｂ,与潜伏态存在的ＲａｊｉＥＢＶ类似。提示鼻咽癌小的ＥＢＶ以潜伏态存在,与ＮＰＣ发病有关。     

乙型肝炎病毒和丙型肝炎病毒的同步PCR扩增

介绍了一种从人血清中同步扩增和检测ＨＢＶ－ＤＮＡ和ＨＣＶ－ＲＮＡ的方法。ＨＣＶ－ＲＮＡ反转录成ｃＤＮＡ,这种ｃＤＮＡ和从ＨＢＶ中抽提出的ＤＮＡ一起,用根据ＨＢＶ、ＨＣＶ保守区序列设计的特异引物进行同步ＰＣＲ扩增,这种方法对于检测ＨＢＶ和ＨＣＶ重复感染很有用处     

蓝舌病病毒Z1株VP7基因的克隆及序列分析

用ＲＴ－ＰＣＲ扩增我国蓝舌病毒Ｚ１株的ＶＰ７基因,直接将其克隆至ｐＧＥＭ－Ｔ载体中,用限制性内切酶ＥｃｏＲＩ分析经蓝／白斑筛选和ＰＣＲ鉴定的重组质粒,用ＤＩＧ标记克隆片段制成探针与病毒基因组进行Ｎｏｒｔｈｅｒｎ ｂｌｏｔ杂交,证明插入片段为ＢＴＶ ＶＰ７基因特异性片段。采用Ｓａｎｇｅｒ双脱氧终止法测定ｃＤＮＡ片段的核苷酸序列,将这一序列与国外已发表的９株蓝舌病毒及相关的环状病毒的ＶＰ７基因进行了比     

抗芜菁花叶病毒转基因甘蓝型油菜的研究

以子叶柄为材料,建立了甘蓝型油菜（ＢｒａｓｓｉｃａｎａｐｕｓＬ．）双低品种的再生体系。通过子叶柄与农杆菌（ＡｇｒｏｂａｃｔｅｒｉｕｍｔｕｍｅｆａｃｉｅｎｓＬＢＡ４４０４）共培养,将表达载体ｐＢＴｕ中芜菁花叶病毒外壳蛋白（ＴｕＭＶ－ＣＰ）基因以整合方式导入甘蓝型油菜,然后用卡那霉素进行筛选,获得了油菜再生植株。经ＰＣＲ特异性扩增、点杂交和Ｓｏｕｔｈｅｒｎ印迹分析,证明再生植株基因组ＤＮＡ中整合了ＴｕＭＶ－ＣＰ基因。攻毒实验表明,有ＴｕＭＶ－ＣＰ基因插入的工程油菜对ＴｕＭＶ均有不同程度的抗性。     

鼻咽癌中Epstein—Barr病毒基因结构特点

鼻咽癌中感染的ＥＢＶ以潜伏态存在,只有少数基因得到表达。我们从分子生物学水平研究其潜伏机制。已知ＲＺＬＦ１基因和ＢａｍＨＩＥＺ片段内部分基因对ＥＢＶ的复制激活起关键作用。我们用体外基因扩增（ＰＣＲ）法扩增ＢＺＬＦ１基因外显子－１序列,并用序列分析法研究了该基因结构特点。此外,检测了ＢａｍＨＩＥＺ片段内的基因缺失,结果发现２１例鼻咽癌（ＮＰＣ）组织中,１１例有ＢａｍＨＩＥＺ片段内缺失,长达２．９９ｋ     

简并引物PCR技术研究洋水仙PVY组病毒初报

利用简并引物ＲＴ－ＰＣＲ扩增技术,结合ＲＴ－ＰＣＲ扩增片段ＲＥＬＰ分析,对洋水仙１４个病毒病样品进行分组检测,结果表明洋水仙植物上存在有四种以上ＰＶＹ组病毒侵染。它们可能是ＴＢＶ、ＮＹＳＶ、ＮＳＳＶ和ＯｎＹＤＶ等。     

用RT-PCR和RFLP对禽传染性支气管炎病毒中国分离株的分型

用ＲＴ－ＰＣＲ方法获取了禽传染性支气管炎病毒（ＩＢＶ）标准毒株Ｍ４１、Ｈ５２、Ａ５９６８和国内分离株Ｄ４１、Ｆ、Ｇ的Ｓ１基因,对它们做ＲＦＬＰ分析,发现Ｄ４１、Ｆ株属于马萨诸塞血清型、Ｇ株为变异株。对用ＲＴ－ＰＣＲ和ＲＦＬＰ来区分ＩＢＶ的分型方法的应用理论和前景进行了论述。     

红皮云杉林的植被分类及其环境解释

红皮云杉林(Picea koraiensis Forest Alliance)是以红皮云杉为群落共优势种的森林植被类型, 具有结构复杂及物种多样性高等特点。在遵从《中国植被志》研编规范的基础上, 提出了红皮云杉林新的分类系统, 包括5个群丛组8个群丛, 分别归属于常绿针叶林、落叶与常绿针叶混交林和针叶与阔叶混交林3个植被型。群丛组分类主要基于群落层片分化, 以及乔木层的共优势种和特征种的差异, 并以常绿针叶树层片重要值的66%为阈值划分常绿针叶林和针叶与阔叶混交林。在群丛分类中, 通过双向指示种分析筛选特征种, 综合考虑群落生境和群落演替阶段等因素确定分类方案。该分类方案是《中国植被志》研编规范的一个应用示例, 对植被分类工作的借鉴意义表现在4个方面。(1) 作为植被分类的重要凭证, 样方数据质量控制是植被分类工作的重要环节; 其中, 物种的准确鉴定对确保植被分类方案的合理性至关重要。(2) 对于乔木层物种组成丰富、优势种不明显的群落, 群落层片分化和特征种是植被类型划分的重要依据。(3) 以特定物种组合为共建种所组成的多个植被类型可归属为不同的植被型。(4) 森林采伐等人类活动可能对植被与环境的关系形成干扰。因此, 在植被分类中应考虑群落的干扰历史和演替阶段等因素。     

Determination of diagnostic species with statistical fidelity measures

Abstract. Statistical measures of fidelity, i.e. the concentration of species occurrences in vegetation units, are reviewed and compared. The focus is on measures suitable for categorical data which are based on observed species frequencies within a vegetation unit compared with the frequencies expected under random distribution. Particular attention is paid to Bruelheide's u value. It is shown that its original form, based on binomial distribution, is an asymmetric measure of fidelity of a species to a vegetation unit which tends to assign comparatively high fidelity values to rare species. Here, a hypergeometric form of u is introduced which is a symmetric measure of the joint fidelity of species to a vegetation unit and vice versa. It is also shown that another form of the binomial u value may be defined which measures the asymmetric fidelity of a vegetation unit to a species. These u values are compared with phi coefficient, chi‐square, G statistic and Fisher's exact test. Contrary to the other measures, phi coefficient is independent of the number of relevés in the data set, and like the hypergeometric form of u and the chi‐square it is little affected by the relative size of the vegetation unit. It is therefore particularly useful when comparing species fidelity values among differently sized data sets and vegetation units. However, unlike the other measures it does not measure any statistical significance and may produce unreliable results for small vegetation units and small data sets. The above measures, all based on the comparison of observed/expected frequencies, are compared with the categorical form of the Dufrêne‐Legendre Indicator Value Index, an index strongly underweighting the fidelity of rare species. These fidelity measures are applied to a data set of 15 989 relevés of Czech herbaceous vegetation. In a small subset of this data set which simulates a phytosociological table, we demonstrate that traditional table analysis fails to determine diagnostic species of general validity in different habitats and large areas. On the other hand, we show that fidelity calculations used in conjunction with large data sets can replace expert knowledge in the determination of generally valid diagnostic species. Averaging positive fidelity values for all species within a vegetation unit is a useful approach to measure quality of delimination of the vegetation unit. We propose a new way of ordering species in synoptic species‐by‐relevé tables, using fidelity calculations.     

Effects of different fidelity measures and contexts on the determination of diagnostic species

Question: How different are lists of diagnostic species of vegetation units, derived using various fidelity measures, in different contexts and with presence/absence versus cover data? Methods: Six different fidelity measures were calculated for vegetation units of two classified data sets covering contrasting types of Central European vegetation (beech forest and dwarf shrub vegetation). Both statistical and non‐statistical fidelity measures were used, and either species presence/absence or cover was considered. Each measure was calculated on four hierarchical levels and within two different contexts, either within the whole data set or within the next higher level of hierarchical classification. Average similarities of the diagnostic species lists derived from various combinations of fidelity measures and contexts were calculated and visualized using principal coordinate analysis (PCoA). Results: The correlations between fidelity values derived from non‐statistical and statistical measures were rather weak. Nevertheless, diagnostic species lists calculated for the same syntaxon by different measures usually had several species in common. Average similarity between pairs of fidelity measures or contexts (based on the Sørensen similarity index) ranged from 0.21 to 0.92. PCoA clustered individual combinations of fidelity measures and contexts mainly according to the context and the use of presence/absence versus cover data, rather than according to the fidelity measures. Conclusions: The strongest impact on the lists of diagnostic species was not the fidelity measure itself but the context of its application and the use of presence/absence or cover data. Despite the weak correlation between individual fidelity values, traditional (non‐statistical) and statistical measures produce quite similar lists of diagnostic species, provided that the context of the analysis is the same. Both approaches have their advantages and disadvantages, and the choice of the appropriate algorithm should depend on the focus of the study.     

Two-step vegetation analysis based on very large data sets

A two-step method for the classification of very large phytosociological data sets is demonstrated. Stratification of the set is suggested either by area in the case of a large and geographically heterogeneous region, or by vegetation type in the case of a set covering all the plant communities of an area. First, cluster analysis is performed on each subset. The resulting basic clusters are summarized by calculating a ‘synoptic coverabundance value’ for each species in each cluster. All basic clusters are then subjected to the same procedure. Second order clusters are interpreted as community types. The synoptic value proposed reflects both frequency and average cover-abundance. It is emphasized that a species should have a high frequency to be used as a diagnostic species. The method is demonstrated with a set of 1138 relevés and 250 species of coastal sand dune vegetation in Yucatan treated with the programs TWINSPAN and TABORD. Some problems and perspectives of the approach are discussed in the light of hierarchy theory and classification theory.     

Characteristics of desert flora and vegetation in lower reach of Shiyang River论Basin

石羊河下游位于干草原向荒漠过渡区域,有天然种子植物23个科,73个属,123个种,不仅有典型的戈壁荒漠成分,也渗入一些草原化荒漠植物种类.其荒漠植被特征更明显,群落层片结构简单,群丛建群种的74.4%是灌木和半灌木,构成了灌木、半灌木旱生群落;1年生草本植物随季节性降雨可形成＂灌草丛＂,成为荒漠植被的重要组成部分.在植物地理区系成分上,温带成分属占优势,其中地中海至中亚分布型及其变型最多,其次为北温带分布及其变型.整个区域内植物的分布集中在生境较适宜的区域,空间结构的成群性高,但在小区域内植物种的分布则较单一.植被可划分为4个植被型,5个植被亚型,13个群系组,23个群系,38个群丛.地域性植被以绿洲为中心,成环状分布,可分为3个带.     

《中国植被志》研编内容与规范

植被志是基于植被(或植物群落)调查资料, 全面记叙植被的外貌、物种组成、结构和功能, 以及地理分布和生境条件等特征, 并对同类植被进行归纳和总结的志书。《中国植被志》是第一部对中国植被进行全面记述的志书, 预计完成约48卷110册。在借鉴《中国植被》(1980)(简称“80方案”)植被分类基本原则的基础上,《中国植被志》将对中国植被分类系统的高级分类单位(植被型组、植被型和植被亚型)进行归纳和总结, 对中级和低级分类单位(群系组、群系、亚群系, 群丛组、群丛)进行详细描述。植被高级分类单位的描述具有概括性质, 是在中国植被分类系统中级和低级分类单位描述的基础上, 对其在全球和中国境内的地理分布、自然环境、群落外貌、植被类型及多样性、优势种或共优势种、生物多样性保育价值以及资源现状等进行概述, 并对“80方案”相关内容进行修订和拓展, 将提供对中国植被基本特征客观、准确的记述。在植被中级和低级分类单位中, 群系组描述的内容包括地理分布、自然环境、群落外貌、植被类型以及价值与保育等内容; 群系描述的主要内容包括地理分布、自然环境、生态特征、物种组成、群落结构、群丛组和群丛的分类与描述、优势种的生物学特性、生物量与生产力、植被动态与演替以及价值与保育等方面。作为植被志研编的核心内容, 群丛组和群丛的分类与描述主要基于植被调查资料, 采用数量分类方法, 根据群落结构和物种组成的差异划分出不同的植被类型, 并对其基本特征进行定量描述和归纳。其中, 群落的层片结构、特定植被分类单元的特征种或特征种组的筛选与甄别是植被类型划分的关键环节; 而群落外貌, 群落结构, 物种组成, 各类物种的生长习性、生境的偏适性等是群丛组和群丛描述与归纳的重点内容。该文提出了中国植被中级和低级分类单位的命名方案, 其特点在于植被类型的科学名称中同时体现了植被分类单元特征种或优势种的名称及其所属的高级植被分类单位(植被型组或植被型)的名称, 兼顾了植被名称的规范性与实用性。《中国植被志》的研编工作由文献整编、群落调查、数据分析与整理、文本撰写等环节组成。该文对植被样方的调查与收集, 文献收集与整编, 气候、土壤、地形等相关数据的来源及其整理方法, 植被分类方法, 植被命名, 植被分类单元描述的内容, 植被志章节编写大纲、体裁及撰写等多个规范进行了详细的阐述或示例。     

Plant communities,diversity and endemism of the Kula Volcano,Manisa, Turkey

Volcanoes often harbour specialized plant communities and shelter endemic plant species. Kula Volcano is one of 14 volcanoes in Turkey. Although this volcano is clearly a landmark of the Aegean region, only few botanical studies analysed the vegetation pattern at the Kula Volcano. None performed a phytosociological classification to delimit different plant communities. We applied a stratified random sampling design according to altitude and aspect and sampled 112 vegetation plots. We classified plant community types using a modified TWINSPAN analysis followed by the determination of diagnostic species based on φ coefficient fidelity values. Floristic relationships between plant community types were interpreted by ordination and ANOSIM analyses. Further, we used partial correlations of the ordination axes and environmental parameters in order to identify relationships between vegetation zonation and environment. We identified five major plant community types based on 85 diagnostic species. These plant community types were significantly correlated with altitude and aspect. Further, 13 endemic plant species were found from which one was endangered and one was classified as vulnerable according to International Union for Conservation of Nature (IUCN).     

Potential replacement vegetation: an approach to vegetation mapping of cultural landscapes

Abstract. The concept of mapping potential replacement vegetation (PRV) is proposed as a parallel to potential natural vegetation (PNV). Potential replacement vegetation (PRV) is an abstract and hypothetical vegetation which is in balance with climatic and soil factors currently affecting a given habitat, with environmental factors influencing the habitat from outside such as air pollution, and with an abstract anthropogenic influence (management) of given type, frequency and intensity. For every habitat, there is a series of possible PRV-types corresponding to the different anthropogenic influences, e.g. grazing, mowing, trampling or growing cereals. The PRV-concept is especially useful in large-scale mapping (scales > 1 : 25 000) of small areas where replacement vegetation is the focus of attention for managers and land-use planners, for example in nature reserves where the aim is conservation of replacement vegetation managed in a traditional way, or in restoration ecology where the concept may be used for defining restoration goals and evaluating the success of restoration efforts. At smaller scales, PRV-mapping may be useful for revealing the biogeographical patterns of larger areas which may be different from the corresponding PNV patterns, because replacement vegetation and natural vegetation may respond to environmental gradients at different scales. An example of medium-scale PRV-mapping through the coincidence of diagnostic species of vegetation types, based on species distribution grid data, is presented. In cultural landscapes, the advantage of using the PRV-concept instead of PNV is its direct relationship to the replacement vegetation. In the habitat mapping with respect to the replacement vegetation, the PRV concept yields more valuable results than the mapping of actual vegetation, as the latter is strongly affected by spatially variable anthropogenic influences which may be largely independent from climatic and soil factors.     

元谋干热河谷生态恢复区昆虫多样性研究

以元谋退化生态系统初始生态恢复中人工构建植被为研究对象,在样地调查的基础上,对比分析了退化生态系统和恢复生态系统昆虫群落多样性组成与结构的恢复状况及其对人工群落类型的生态响应。结果表明,植物群落组成是影响昆虫群落多样性的关键因子。与天然植被相比,混交林促进了昆虫在退化地的扩散和定居,物种多样性明显增加。主成分分析排序将6种生境分为两大类:第Ⅰ类为赤桉纯林,代表物种单一、林下空旷、环境干燥为特点的植被;第Ⅱ类为扭黄茅草坡、车桑子灌丛及赤桉 银合欢、赤桉 相思、相思 银合欢3种混交林,代表物种相对复杂,生境偏向湿润的植被。不同生境的特有昆虫和优势昆虫种类和数量分析表明,在3种混交林中,相思 合欢恢复的效果较赤桉 相思与赤桉 合欢显著,是最好的先锋群落植物混交模式,能够较快改良生境,提高其物种多样性。但由于造林面积较小,植被恢复时间短,受人为干扰较大,昆虫多样性恢复的效果还不明显。