Species distinction within Campanula sect. Heterophylla in the SW Alps: Molecular,morphological and chemotaxonomic evidences

In this study, we attempted to solve species distinction among some endemic and widespread representatives of Campanula sect. Heterophylla living in the SW Alps. Molecular and morphological investigations were congruent in detecting some taxa such as C. cochleariifolia, C. sabatia, C. bertolae, C. fritschii and partially C. macrorhiza. Otherwise C. stenocodon and C. rhomboidalis were detected by morphology only. Finally, C. rotundifolia and C. scheuchzeri were never detectable with all the analyses applied. The species of the sect. Heterophylla living in the same geographical area show a high likelihood of genetic exchanges. They are recognized sometimes only on the base of small morphological details and according to their ecology. Chemotaxonomic investigations are only partially useful for species distinction. The combination of different analyses might constitute a reliable tool for the taxonomy of most of the species belonging to the sect. Heterophylla.     

两栖蓼的分子系统学研究

两栖蓼是一种水陆两栖植物,植株在不同生态环境下外部形态差异较大,同时两栖蓼的系统位置存在争议,被归入春蓼组(sect.Persicaria)或提升为两栖蓼组(sect.Amphibium)。该文选取两栖蓼及春蓼组植物12种,以及刺蓼组、头状蓼组、神血宁组、拳参组、萹蓄组和外类群掌叶大黄共23种植物进行研究。植物总DNA的提取采用改进的CTAB法,所测序列以及从Genbank数据库下载的序列,以掌叶大黄为外类群,采用最大简约法和贝叶斯法对核糖体ITS序列和叶绿体trn L-F序列进行了系统发育分析。ITS序列对位排列的长度为735 bp,包括489个可变位点,272个位点是信息位点。简约法得到9个简约树,步长为1 084,CI指数为0.680,RI指数为0.614。trn L-F序列对位排列的长度为1 121 bp,包括427个可变位点,239个位点是信息位点。简约法寻找到9个简约树,步长为551(CI=0.911,RI=0.910)。贝叶斯法和简约法得到的树基本一致。分子序列分析结果显示,trn L-F序列树类似于ITS序列树。ITS序列构建的发育树上,两栖蓼与刺蓼组植物、春蓼组其他植物形成3个并列的分支;在trn L-F序列树上,两栖蓼则与其他春蓼组植物形成两个并列的分支。由此可见,两栖蓼与春蓼组其他植物的亲缘关系较远,成一独立的分支。两个分子证据支持将两栖蓼提升为两栖蓼组的处理意见。此外,两栖蓼的花粉具散沟,与典型的春蓼组的具散孔花粉不一致。再加上两栖蓼水陆两栖的特性,因此支持把两栖蓼提升为两栖蓼组的观点。两栖蓼组的界定为多年生草本,水陆两栖,根状茎横生,生于水中茎漂浮,叶长圆形或椭圆形,生于陆地茎直立,叶披针形或长圆状披针形,托叶鞘为筒状、薄膜质,总状花序穗状,瘦果近圆形,花粉具散沟。     

DNA barcoding in closely related species: A case study of Primula L.sect.Proliferae Pax (Primulaceae) in China

DNA barcoding is a method of identifying species by analyzing one or a few short standardized DNA sequences. There are particular challenges in barcoding plants, especially for distinguishing closely related species. Hence, there is an urgent need to evaluate the performance of candidate loci for distinguishing between species, especially closely related species, to complement the rbcL + matK combination suggested as the core barcode for land plants. We sampled 48 individuals representing 12 species in Primula sect. Proliferae Pax in China to evaluate the performance of eight leading candidate barcode loci (matK, rbcL, rpoB, rpoCl, trnH-psbA, psbK-psbI, atpFatpH, and internal transcribed spacer (ITS)). The core combination rbcL + matK gave only 50% species resolution in sect. Proliferae. In terms of intraspecies and interspecies divergence, degree of monophyly, and sequence similarity, ITS, trnH-psbA, and psbK-psbI showed good performance as single-locus barcodes. Internal transcribed spacer displayed the highest genetic divergence and best discriminatory power, both alone and in combination with rbcL +matK (83.3% species resolution). We recommend evaluating the use of ITS for barcoding in other species. Low or single copy nuclear regions would provide more sophisticated barcoding tools in the long term, even though further research is required to find suitable loci.     

A NEW SPECIES OF VOLVOX SECT. MERRILLOSPHAERA (VOLVOCACEAE,CHLOROPHYCEAE) FROM TEXAS1

Smith (1944) divided the familiar genus Volvox L. into four sections, placing seven species that lacked cytoplasmic bridges between adult cells in the section Merrillosphaera. Herein, we describe a new member of the section Merrillosphaera originating from Texas (USA): Volvox ovalis Pocock ex Nozaki et A. W. Coleman sp. nov. Asexual spheroids of V. ovalis are ovoid or elliptical, with a monolayer of 1,000–2,000 somatic cells that are not linked by cytoplasmic bridges, an expanded anterior region, and 8–12 gonidia in the posterior region. Visibly asymmetric cleavage divisions do not occur in V. ovalis embryos as they do Volvox carteri F. Stein, Volvox obversus (W. Shaw) Printz, and Volvox africanus G. S. West, so the gonidia of the next generation are not yet recognizable in V. ovalis embryos prior to inversion. Molecular phylogenetic analyses of the five chloroplast genes and the internal transcribed spacer (ITS) regions of nuclear rDNA indicated that V. ovalis is closely related to Volvox spermatosphaera Powers ( Powers 1908 , as “spermatosphara”) and/or Volvox tertius Art. Mey.; however, V. ovalis can be distinguished from V. spermatosphaera by its larger gonidia, and from V. tertius by visible differences in gonidial chloroplast morphology.     

A new species of Centaurea L. (Cardueae: Asteraceae) from Turkey

A new species of Centaurea L., C. kizildaghensis (Cardueae: Asteraceae), is described and illustrated from south Anatolia. It is restricted to the serpentine rocky slopes of Kızıl Dağ (C3 Konya–Derebucak, Çamlık), and is closely related to C. pseudokotschyi Wagenitz and C. drabifolioides Hub.-Mor., from which it differs in stem, leaf, and phyllary appendage characters. The diagnostic morphological characters are discussed. A new key is produced for Group G species for the flora of Turkey.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 61–66.     

The discovery and phylogenetic implications of a novel 41 bp plastid DNA deletion in wild potatoes

Insertions and deletions (indels) are common in intergenic spacer regions of plastid DNA and can provide important phylogenetic characters for closely related species. For example, a 241-bp plastid DNA deletion in the trnV-UAC/ndhC intergenic spacer region has been shown to have major phylogenetic importance in determining the origin of the cultivated potato. As part of a phylogenetic study of the wild potato Solanum series Piurana group we screened 199 accessions of 38 wild potato species in nine of the 19 tuber-bearing (Solanum section Petota) series that have not been examined before for indels in the trnV-UAC/ndhC intergenic spacer region. A novel 41 bp deletion (but no 241 bp deletion) was discovered for 30 accessions of three species: S. chiquidenum (5 of 10 accessions), S. chomatophilum (19 of 28), and S. jalcae (6 of 6). Accessions with and without this deletion are found throughout much of the north-south range of all three species in northern and central Peru, but not east of the Marañón River. Multivariate morphological analyses of these 44 accessions showed no morphological associations to the deletion. The results suggest extensive interspecific gene flow among these three species, or a common evolutionary history among species that have never been suggested to be interrelated.     

铁线莲属铁线莲组修订

(1)对毛莨科铁线莲属Clematis的铁线莲组sect.Viticella进行了分类学修订,确定此组包含13种,1亚种和2变种(包括2新种和1新变种等级),写出此组的分类学简史和地理分布;将此组划分为3亚组,4系,写出区分组下各级分类群的检索表,以及各种植物的形态描述,地理分布,生长环境等,并附有多幅插图。(2)特产我国东部的单型毛萼铁线莲亚组subsect.Hancockianae(花具4枚平展,不展宽的萼片,雄蕊无毛)被认为此组的原始群。铁线莲亚组subsect.Floridae(花具5-8枚平展,强烈展宽的萼片,雄蕊无毛,花粉具散孔)和湖州铁线莲亚组subsect.Viticellae(花具4枚渐升,多少展宽的萼片,雄蕊花丝常被缘毛,花粉具3沟)可能均由毛萼铁线莲亚组衍生而出。(3)在我国东部集中分布此组的3亚组,3系的8种,1亚种和1变种,这里是此组的分布中心,也可能是此组的起源中心。     

铁线莲属尾叶铁线莲组(毛茛科)基于形态学证据的分支系统学

选取铁线莲属（Clematis）尾叶铁线莲组（sect．Campanella）中37个种以及西南铁线莲组（sect．Bebaeanthera）中的2个种为内类群，以Clematis altemata作为外类群，通过对全世界10个标本馆的近2000份腊叶标本的形态学特征统计，选取了35个性状进行编码，利用PAUP 4．0 beta 10软件进行系统发育重建。通过最简约法（maximum parsimony）分析共得到182棵最简约分支树，树长为182步，一致性指数（CI）=0．385，保持性指数（RI）=0．685。结果表明：（1）尾叶铁线莲组并非是一个单系类群：（2）以花序发生位置这一性状建立的sect．Bebaeanthera不能成立，应并入尾叶铁线莲组：（3）本研究结果不支持在尾叶铁线莲组中建立subsect．Henryianae或ser．Henryianae；（4）C．ranunculoides等萼片外面具纵翅的一群植物与本组中萼片红色的种类C．lasiandra和C．dasyandra有较近的亲缘关系：（5）C．otophora、C．pogonandra、C．repens和C．barbellata等几个种聚为一支，且支持率很高，它们具有一系列的共衍征，即萼片质地较厚，花丝扁平，宽条形，被短柔毛，花药被黄色短毛，药隔先端凸起，因此不支持建立Ser．Pogonandrae；（6）本组中非洲分布的2个种无论从形态上还是从地理分布和生境上都十分特殊，是本组植物的特化类群。     

What is Allium paniculatum? Establishing taxonomic and molecular phylogenetic relationships within A. sect. Codonoprasum

Allium paniculatum L. is commonly recorded from the Euro-Mediterranean and Irano-Turanian regions. Evidence from literature and herbarium collections revealed that many different taxa of A. sect. Codonoprasum Rchb., all characterized by big size, diffuse and densely flowered umbrella, very long spathe valves, long pedicels, and cylindrical-campanulate perigon, have been wrongly attributed to this species thus affecting records on its geographic distribution and morphological characterization. In order to define the true identity of A. paniculatum, we analyzed specimens coming from the type locality (Don River), and provided details on morphology, ecology, karyology, leaf anatomy, seed morphology and seed coat micro-sculpturing. Taxonomic and phylogenetic relationships with related species of sect. Codonoprasum and with other taxa of different sections were investigated by means of morphological characters and molecular data from the internal transcribed spacers (ITS) nrDNA and the trnH-psbA cpDNA region. Maximum parsimony and Bayesian inference analyses of molecular data recovered two main clades in A. sect. Codonoprasum and clearly separated A. paniculatum from related taxa. The taxonomic implications of these patterns of relationships are discussed. To our knowledge, this is the first study documenting in-depth phylogenetic relationships within A. sect. Codonoprasum.     

Warm–cold colonization: response of oaks to uplift of the Himalaya–Hengduan Mountains

Clarifying the relationship between distribution patterns of organisms and geological events is critical to understanding the impact of environmental changes on organismal evolution. Quercus sect. Heterobalanus is now distributed across the Himalaya–Hengduan Mountains (HHM) and warm lowland in East China, yet how the distribution patterns of this group changed in response to the HHM uplift remains largely unknown. This study examines the effect of tectonic events in the HHM region on the oaks, providing a biological perspective on the geological history of this region. Fifty‐six populations of Quercus sect. Heterobalanus were genotyped using four chloroplast DNA regions and nine nuclear simple sequence repeat loci to assess population structure and diversity, supplemented by molecular dating and ancestral area reconstructions. The underlying demographic dynamics were compared using ecological niche models of the species distributions during the last glacial maximum and the present. These analyses illustrate that Quercus sect. Heterobalanus diversified as the HHM uplifted and climatic cooling during the mid‐Miocene, colonizing the cold habitats from warm broadleaf mixed forests. Lineages in cold highlands and warm lowlands have diverged as a consequence of local adaptation to diverging climates since the late Miocene. Our results suggest that continuous uplift of the HHM in the late Miocene to early Pliocene accompanied by simultaneous cooling triggered the differentiation of oaks. The biogeography of Quercus sect. Heterobalanus illuminates the geological events responsible for the modern‐day HHM.