基于毛髓质指数探讨甘肃鼢鼠、高原鼢鼠、秦岭鼢鼠的分类地位

目前甘肃鼢鼠Myospalax cansus、高原鼢鼠 M.baileyi、秦岭鼢鼠M.rufescens的分类地位一直存有争议,多涉及到与中华鼢鼠M.fontanierii的分类关系.本文分别从成体甘肃鼢鼠、高原鼢鼠、秦岭鼢鼠、中华鼢鼠标本的胡须、头部、背部、腹部、前肢取毛样,经清洗和处理后,在倒置显微镜下观察,用目镜测微尺分别测量和计算其5个部位毛发的毛髓质指数.结果表明:甘肃鼢鼠与中华鼢鼠除胡须髓质指数无显著性差异外,其它部位及各部位综合均有显著差异.高原鼢鼠与秦岭鼢鼠除前肢毛髓质指数无显著性差异外,其它部位及各部位综合均有显著差异;与中华鼢鼠除前肢毛髓质指数无显著差异,其它部位及各部位综合均有显著差异.秦岭鼢鼠除与甘肃鼢鼠的腹部及与中华鼢鼠、高原鼢鼠的前肢毛髓质指数无显著差异外,与其它鼢鼠其余部位及各部位综合均有显著性差异.综合考虑,本研究结果支持甘肃鼢鼠、高原鼢鼠、秦岭鼢鼠各自独立为种的观点.     

Genome-based taxonomic classification of the closest-to-Comamonadaceae group supports a new family Sphaerotilaceae fam. nov. and taxonomic revisions

Many genera closest to the family Comamonadaceae have not been classified into any family; moreover, some of them are not monophyletic groups beyond the genus level. To resolve the taxonomic uncertainty of the closest-to-Comamonadaceae (CTC) group, we performed 16S rRNA gene- and genome-based phylogenetic analyses combined with genome relatedness indices and phenotypic traits comparison. Phylogenies based on the 16S rRNA gene and genome sequences demonstrated that the CTC group formed a coherent and robust monophyletic lineage and was sister to the family Comamonadaceae, thereby proposing the CTC group as a novel family, Sphaerotilaceae fam. nov. The resolved genus- and species-level taxonomic relationships of this new family were then validated by the phylogenomic reconstruction and comparisons of genome relatedness indices including digital DNA-DNA hybridization and average nucleotide identity (ANI) as well as comprehensive phenotypic analysis for type strains. Finally, we reclassified all misidentified genera and species, resulting in 19 new combinations, and proposed Sphaerotilaceae-specific thresholds of ANI and average amino acid identity for genus delineation. Collectively, this study has established a sound taxonomic framework of the novel family Sphaerotilaceae and will help guide future taxonomic efforts and prevent the propagation of taxonomic errors.     

泛喜马拉雅地区铁线蕨属细叶铁线蕨系的分类学修订

在标本研究和野外考察的基础上,结合微形态分析结果和植物地理学资料,对泛喜马拉雅地区铁线蕨属细叶铁线蕨系进行丫分类学修订。研究结果表明该系植物囊群盖的形状、末回小羽片上缘锯齿的形态和鳞片微形态特征是物种划分的重要性状。承认泛喜马拉雅地区该系植物分布有7种和2变种,分别是陇南铁线蕨Adiantum roborowskii、肾盖铁线蕨A．roborowskiivar．robustum、毛足铁线蕨A．bonatianum、冯氏铁线蕨A．fengianum、长盖铁线蕨A．fimbriatum、白背铁线蕨A．davidii、长刺铁线蕨A．davidiivar．longispina、细叶铁线蕨A,venustum和西藏铁线蕨A．tibeticum。对三个分类学名称进行了归并,即将圆齿铁线蕨Adiantun breviserratum处理为长盖铁线蕨A．fimbriatum的异名,肾盖铁线蕨Adiantum erythrochlamys处理为A．roborowskii var．robustum的异名．无芒铁线蕨Adiantum bonatianum var．subaristatum处理为毛足铁线蕨A．bonatianum的异名。     

中国特有属藤山柳属 (猕猴桃科) 的花粉形态及其分类学意义

摘要：藤山柳属Clematoclethra为中国特有属,属内物种划分争议颇大。利用扫描电镜观察了该属14个居群的花粉形态,结果表明藤山柳属的花粉为小粒花粉,多为圆球形,具三拟孔沟,根据外壁纹饰可分为皱波状花粉、颗粒状花粉和细疣状花粉3种类型。花粉类型与植株毛被特征有一定相关性,对澄清藤山柳属的分类问题具有一定意义。     

广义报春苣苔属 (苦苣苔科) 的染色体新计数及其分类学意义

报道了广义报春苣苔属14种3变种和7个未定名种的染色体数目,并对其近缘属——广义石山苣苔属的3个种也进行了细胞学研究。结合最近的分类处理和系统发育假设,对所得结果和以前发表的染色体数据进行了综合分析, 结果表明：广义报春苣苔属的染色体数目为2n=36,基数为x=18,表现出高度稳定性。染色体相对较小,以中间着丝粒和亚中间着丝粒染色体为主。尽管一些类群的染色体大小之间存在微小差异,但是染色体形态的均一性和染色体数目的一致性有力地支持分子系统学的研究结果。另外,相同的染色体数目及相似的染色体形态也表明广义报春苣苔属和广义石山苣苔属的亲缘关系较近,与分子系统学的结果一致。     

Review of ‘The Plant List,a working list of all plant species’

The Plant List ( http://www.theplantlist.org/ ) is an on‐line database of plant names that aims to be comprehensive for all described plant species. Version 1 of The Plant List includes 1 040 426 plant name records, of which 298 900 are accepted names. The Plant List is the product of a consortium of the Royal Botanic Gardens, Kew, and the Missouri Botanical Garden. In this review, I evaluate the use of this plant taxonomic database for plant ecologists. The web interface of The Plant List allows a quick search for species names and corresponding synonyms. Moreover, users are able to download search or browse results to compile a customized checklist of plant names. The combination of a straightforward web design and the possibility to download search results provides a valuable resource of plant nomenclature information for a wide range of plant ecologists.     

Contrasting levels of genetic differentiation among putative neutral microsatellite loci in Atlantic herring Clupea harengus populations and the implications for assessing stock structure

Porifera is a primarily marine phylum comprising more than 15,000 species. The successful and wide adaptive radiation of freshwater sponges (Haplosclerida: Spongillina) has resulted in the colonization of an extremely wide variety of habitats at all latitudes. Colonization is dated back to the Mesozoic, and the mono- or poly-phyletism of Spongillina, and the number of potential sponge invasions into freshwater is still under debate. Living freshwater sponges belong to 45 genera in six families for a total of 219 species. The highest diversity, at the scale of zoogeographic regions, is recorded from the Neotropical (65 species), Palaearctic (59 species), and Afrotropical regions (49 species). Endemic freshwater sponge species are 103 (47%) out of 219. All species belonging to the families Lubomirskiidae, Metschnikowiidae, and Malawispongiidae are endemic. Endemic species among the other families are 72% for Potamolepidae, 38% for Spongillidae, and 32% for Metaniidae. Data on some wide geographic areas are scattered and fragmentary if not almost completely lacking. Species richness is probably underestimated and doubtless destined to increase with further research. Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens Freshwater Animal Diversity Assessment     

非环境类因子对物种数目协同变化的影响

不同分类类群的物种数目常在空间上表现出显著相关地协同变化,但哪些相关系数之间存在较大的差异？究竟是什么因素导致了这种差异是值得关注的问题。从不同作者的研究方法和数据来源来看,不同研究中的研究方法、研究区域和环境条件本身就存在着差异。除以上影响因子外,我们分析了非环境类因子对物种数目协同变化的影响。结果发现分类类群间的物种数量协同变化差异明显,只有起源和生境要求相似的类群间呈显著性相关;不同鸟兽间的协同变化不存在面积效应,但是空间尺度间的相关性差异明显：物种分布型中东洋型物种的协同变化明显,而广布型和古北型不明显;在鸟类居留型中繁殖鸟与兽类的协同变化极为显著,而其他类型则不显著。综上所述,物种数量协同变化的非环境类影响因子中,生态类型和起源对分类类群间的物种数目协同关系有重要影响,     

国产省藤属植物的叶表皮形态学

对国产省藤属（Calamus L．）植物17种2变种的叶表皮进行光学显微镜观察,除单叶省藤（C.simplicifolius）、短叶省藤（C.egregiw）和白藤（C.tetradactylus）外,其它种均为首次报道。省藤属植物的叶表皮形态较为一致,气孔器为轮列4细胞型（tetracytic,或称四轮列型）,即有4个副卫细胞,其中2个为侧副卫细胞,2个为端副卫细胞;表皮细胞为长方形,纵向排列。表皮毛有3种类型：多细胞排成单列的单毛（人喙省藤C．macrorrhynchus）、多细胞排成2-3列的单毛（毛鳞省藤ethysanolepis等）、多细胞分枝毛（白藤等）。表皮细胞的长度和宽度特征、细胞壁的厚薄及波纹的深浅和形状、端副卫细胞的长短等细微特征在种问存在差异,可以区分种类。叶表皮结构还反映了种问的亲缘关系。因此,叶表皮特征对于省藤属种类的划分和亲缘关系的确定有较大的分类学意义。     

中国地鼠线粒体Cyt b基因测序及其分子进化

目的测定中国地鼠线粒体DNA细胞色素b基因部分序列,分析其分子系统进化关系。方法提取中国地鼠肝脏的总基因组DNA。设计合成特异引物进行PCR扩增,经检测进行测序。用Blast与GenBank中啮齿类其他常用实验动物的物种细胞色素b基因进行同源序列比较,分析其碱基组成及变异情况,并用邻接法、最大简约法、最小进化法构建了分子系统树,在分子水平上探讨中国地鼠和常用啮齿类实验动物的进化关系。结果获得了中国地鼠线粒体Cytb基因的部分序列,共936bp。结论中国地鼠和金黄地鼠的亲缘关系最近,与小鼠、大鼠存在的差异相对大,与豚鼠的亲缘关系最远,与传统的分类地位基本吻合。