Chloroplast matK gene phylogeny of Taxaceae and Cephalotaxaceae,with additional reference to the systematic position of Nageia

Reported in the present paper is a robust chloroplast matK gene phylogeny of Taxaceae, Cephalotaxaceae and Podocarpaceae represented by 10 species of seven genera, with three species of the Pinaceae as outgroups. The matk length of the 13 species ranges from 1488 bp to 1548 bp, which results from indels, in particular, 1-bp(base pair) insertion near the 3’ end of the gene in some groups. A 27 bp deletion was found at the nucleotide position 213 from the 5’ end of the matk gene of Pseudotaxus chienii. The aligned sequences used in PAUP and MEGA analyses were 1568 bp and 1494 bp respectively. In the matK gene, the rates of variation at the first, second and third codon positions are similar although the mean frequency of synonymous substitution is approximately twice as high as that of nonsynonymous substitution. Branch-and-Bound search found only one most parsimonious tree (tree length = 895, CI = 0.850, RI = 0. 876), in which all clades were strongly supported by bootstrap test. According to the tree, Taxaceae and Cephalotaxaceae are monophyletic groups, and the sister group relationship between the two families was confirmed. Taxus is closely related to Pseudotaxus while Torreya is the sister group of Amentotaxus. In addition, the close relationship between Nageia and Podocarpus was resolved. The present study supports the generic status of Pseudotaxus and Amentotaxus in point of cladistic analysis and genetic distance, but contra-dicts the establishment of the family Nageiaceae.     

Surface wax, a new taxonomic feature in Plagiochilaceae

A scanning electron microscope study of 81 species of Plagiochilaceae revealed the presence of superficial waxes on the leaves and stems ofPlagiochilion mayebarae and 5 species ofPlagiochila. The waxes are not visible in the light microscope and were unknown in Plagiochilaceae.Plagiochila fuscolutea andP. longiramea (=P. sect.Fuscoluteae) are characterised by the predominant occurrence of membraneous wax platelets;Plagiochila aerea, P. rudischusteri andP. tabinensis(=P. sect.Bursatae) predominately form various types of wax rodlets. Our findings show for the first time the systematic usefulness of leaf surface waxes in the liverworts.P. tabinensis contains surface waxes in amounts of ca. 1.4% dry weight composing of steryl esters, triacylglycerols and free fatty acids.     

A revision of Clematis sect. Clematis(Ranunculaceae)

Clematis sect. Clematis is revised in this paper. Seventy-three species and 45 varieties are recognized. They are keyed, described, and illustrated in some cases, and are classified into five subsections. Brief taxonomic history and geographical distribution of the section are given, and the relationships of its subsections and with its close allies of the C. vitalba evolutionary stock of the subgenus Clematis are discussed. Main taxonomic changes are made as follows: (1) C. lancifolia Bur. & Franch., C. songarica Bunge, C. ispahanica Boiss., C. delavayi Franch. and C. phlebantha Williams, which have been previously regarded to be close to C. fruticosa Turcz. and its allies, and placed in sect. Fruticella Tamura by Tamura and some other authors, are here transferred to subsect. Angustifoliae Tamura according to the floral structure. (2) The existence of intermediate forms between the C. vitalba group and the C. flammula group indicates that these two groups are closely related to each other and should not be treated as two sections or even two subgenera. They are treated as two subsections within sect. Clematis . Two series, six species, and one variety are described as new, and five new ranks are made.      

Iridoid glucosides of the genus Veronica s.l. and their systematic significance

 The mode of reproduction, pollen production, chromosome numbers, genetic variation (RAPD, allozymes) and overall similarity were studied in 6 species of Hieracium sect. Alpina in the Tatry Mts. (the Western Carpathians, Slovakia). All species were confirmed to be agamospermous and, except of H. krivanense and H. slovacum, lacking pollen grains. For the first time, a chromosome number is reported for H. krivanense (2n=4x=36). Considerable genetic variation was revealed in H. alpinum and a correlation between geographic and genetic distances was found in this species. Between-population variation in RAPD and allozyme phenotypes was found in H. pinetophilum and H. crassipedipilum. In all other species, allozyme and RAPD variation was low or absent. With few exceptions, the species differ in their allozyme as well as RAPD patterns. The relatedness of one population of endemic H. slovacum and H. halleri was confirmed. It is shown, that Carpathian species of the H. fritzei group are derived from at least two ancestors. Received July 3, 2000; accepted June 24, 2002 Published online: November 20, 2002 Addresses of the authors: H. Štorchová, (e-mail: storchova@ueb.cas.cz) Institute of Experimental Botany, Academy of Sciences of the Czech Republic, Rozvojová 135, CZ-165 00 Praha 6, Czech Republic. I. V. Bartish, J. Chrtek Jr., J. Kirschner, M. Tetera, J. Štěpánek, Institute of Botany, Academy of Sciences of the Czech Republic, CZ-252 43 Pruhonice, Czech Republic.     

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.     

爵床科孩儿草属一新组

描述了爵床科孩儿草属的一个新组-密花孩儿草组Rungia sect．Stoloniferoe C．M．Gao＆Y．F．Deng。本新组花序不偏向一侧,苞片均能育,同形。     

7种金花茶组植物叶片营养成分分析

为选育金花茶优良品种，以7种金花茶组(Camellia sect. Chrysantha)植物成熟叶片为试材，对其总黄酮、茶多酚、总多糖、总皂苷、总氨基酸及维生素E等6种营养物质及K、Ca、Na、Fe、Mn、Zn、Se等7种矿质元素含量进行测定比较，通过聚类分析，考查不同金花茶组植物叶片间存在的药用价值差异。结果表明，7种金花茶组植物叶片的营养成分含量丰富且存在显著差异：凹脉金花茶(Camellia impressinervis)的茶多酚含量最高，达7.13%；东兴金花茶(C. tunghinensis)的总皂苷含量最高，达0.41 g·100 g^-1；柠檬金花茶(C. limonia)的总黄酮含量最高，达671.67 mg·100 g^-1。矿质元素方面各种类均呈现高钾低钠的特征，凹脉金花茶、柠檬金花茶和小果金花茶(C. nitidissima var. microcarpa)K含量高于Ca，且各品种中均检测出Se元素。综合结果表明，凹脉金花茶叶片中茶多酚、总多糖、总氨基酸等各类营养成分含量相对较高，具有潜在的研究与开发价值。