靖西长喙木兰，广西木兰科一新种（英文）

描述了产自广西木兰科一新种：靖西长喙木兰(Lirianthe jingxiensis Y. H. Tong&N. H. Xia)。本种形态上与绢毛木兰[L. albosericea(Chun&C. H. Tsoong)N. H. Xia&C. Y. Wu]接近,但区别在于该种植株较矮,幼枝、叶柄和幼叶被黄棕色绢毛,叶柄较宽,叶片较宽,倒卵形或倒卵状椭圆形,先端钝或短渐尖,花被片较大,心皮数目较多,被黄棕色绢毛。     

Nelumbonaceae:Systematic position and species diversification revealed by the complete chloroplast genome

<正>Nelumbonaceae is a morphologically unique family of angiosperms and was traditionally placed in Nymphaeales;more recently,it was placed in Proteales based on molecular data,or in an order of its own,Nelumbonales. To determine the systematic position of the family and to date the divergence time of the family and the divergence time of its two intercontinentally disjunct species,we sequenced the entire chloroplast genome of Nelumbo lutea and most of the chloroplast genes of,N.nucifera.We carried out phylogenetic and molecular dating analyses of the two species and representatives of 47 other plant families,representing the major lineages of angiosperms, using 83 plastid genes.The N.lutea genome was 163 510 bp long,with a total of 130 coding genes and an overall GC content of 38%.No significant structural differences among the genomes of N.lutea,Nymphaea alba, and Platanus occidentalis were observed.The phylogenetic relationships based on the 83 plastid genes revealed a close relationship between Nelumbonaceae and Platanaceae.The divergence times were estimated to be 109 Ma between the two families and 1.5 Ma between the two Nelumbo species.The estimated time was only slightly longer than the age of known Nelumbo fossils,suggesting morphological stasis within Nelumbonaceae.We conclude that Nelumbonaceae holds a position in or close to Proteales.We further conclude that the two species of Nelumbo diverged recently from a common ancestor and do not represent ancient relicts on different continents.     

中国茜草属sect.Oligoneura的形态计量学研究

茜草属为茜草科模式属,全球约80种,中国有近一半的物种,是茜草属的重要分布中心,大部分隶属于sect.Oligoneura。但是,该组内各种间的形态特征错综复杂,依靠单个性状不易划定种间界限。该研究在全面衡量sect.Oligoneura组内各种间形态特征的基础上,选取该组20种共171份标本,对其3个数量性状和28个定性性状进行聚类分析和主成分分析。结果表明:在主成分分析中,前3个主成分累积贡献率有46.88%,性状的累积贡献率增长并不明显,但该结果仍与聚类分析结果一致。对前3个主成分贡献较大的特征包括叶形(叶长宽比)、叶柄长度、叶脉、每轮叶片数和生活型等,这些形态性状也是该属传统分类学中重要的物种鉴定特征。该研究结果与分子系统发育结果基本一致,支持该组内ser.Chinenses、R.mandersii group、R.angustissima group和R.siamensis group类群的划分,但并不支持ser.Cordifoliae单独成系。sect.Oligoneura内除少数物种外,大部分物种界限均比较清晰。形态计量学研究为sect.Oligoneura甚至茜草属的物种鉴定与划分提供了重要的参考意义。     

报春花属藏报春组、毛茛叶报春组的界定和系统发育关系:核糖体DNA ITS序列证据

报春花属(Primula L.)藏报春组(sect. Auganthus Pax ex Balf. f.)和毛茛叶报春组(sect. Ranunculoides Chen et C. M. Hu)的界定一直是没有解决的问题.应用核糖体DNA ITS序列数据探讨其系统发育关系.取样包括藏报春组和毛茛叶报春组的全部5个种以及其他一些相关组的代表种.ITS系统树表明,陕西羽叶报春(P.filchnerae Knuth)应与藏报春(P. sinensis Sabine ex Lindl.)和野藏报春(P. rupestris Balf. f. et Farrer)一起置于藏报春组;毛茛叶报春组只含两种:毛茛叶报春(P. cicutariifolia Pax)和安徽羽叶报春(P. merrilliana Schltr.).这两组并不具密切亲缘关系,它们在报春花属中与其他组的关系还需进一步研究.研究也表明ITS序列可以为报春花属的系统发育重建提供大量可靠资料.     

用于叶绿体遗传转化的表达载体

叶绿体遗传转化是植物基因工程的新方向。本文简要介绍用于叶绿体遗传转化的表达载体的构建方法,涉及同源重组片段、叶绿体特异的启动子和终止子、筛选标记基因,以及目前在叶绿体中已实现表达的外源基因等内容。 Abstract:Chloroplast genetic transformation is a new way of plant genetic engineering.This paper reviews the construction methods of expression vector used in chloroplast genetic transformation.It contains the homologous recombinant fragments,the chloroplast specific promoter and terminater,the selectable marker genes and the interest genes whose expression in chloroplast have been achieved.     

Phylogenetics of early branching eudicots:Comparing phylogenetic signal across plastid introns,spacers,and genes

<正>Recent phylogenetic analyses revealed a grade with Ranunculales,Sabiales,Proteales,Trochodendrales, and Buxales as first branching eudicots,with the respective positions of Proteales and Sabiales still lacking statistical confidence.As previous analyses of conserved plastid genes remain inconclusive,we aimed to use and evaluate a representative set of plastid introns(group I:trnL;group II:petD,rpll6,trnK) and intergenic spacers(trnL-F,petB-petD, atpB-rbcL,rps3-rpl16) in comparison to the rapidly evolving matK and slowly evolving atpB and rbcL genes. Overall patterns of micro structural mutations converged across genomic regions,underscoring the existence of a general mutational pattern throughout the plastid genome.Phylogenetic signal differed strongly between functionally and structurally different genomic regions and was highest in matK,followed by spacers,then group II and group I introns.The more conserved atpB and rbcL coding regions showed distinctly lower phylogenetic information content.Parsimony,maximum likelihood,and Bayesian phylogenetic analyses based on the combined dataset of non-coding and rapidly evolving regions(14 000 aligned characters) converged to a backbone topology of eudicots with Ranunculales branching first,a Proteales-Sabiales clade second,followed by Trochodendrales and Buxales. Gunnerales generally appeared as sister to all remaining core eudicots with maximum support.Our results show that a small number of intron and spacer sequences allow similar insights into phylogenetic relationships of eudicots compared to datasets of many combined genes.The non-coding proportion of the plastid genome thus can be considered an important information source for plastid phylogenomics.     

Molecular phylogeography and evolutionary history of Picea likiangensis in the Qinghai-Tibetan Plateau inferred from mitochondrial and chloroplast DNA sequence variation

The aim of the present study was to examine the phylogeographic and evolutionary history of Picea likiangensis,a dominant species of the conifer forests in the eastern declivity of the Qinghai-Tibetan Plateau. We collected 422 individuals from 42 natural populations of three major varieties classified under this species.In conifers,mitochondrial(mt) DNA and chloroplast(cp) DNA dispersed by seeds or pollen experience very different levels of gene flow.To this end,we examined the sequence variation of two mtDNA fragments(nad5 intron 1 and nad1 intron b/c) and three cpDNA fragments(trnL-trnF,trnS-trnG and nadhK/C).We found that cpDNA probably introgressed from P.purpurea into remote populations of P.likiangensis through long-distance dispersal. Multiple refugia seem to have been maintained for P.likiangensis during the Last Glacial Maximum because the cpDNA and mtDNA haplotypes recovered were fixed in the different regions.Postglacial expansions were only detected at the distributional edges of this species where a single cpDNA or mtDNA haplotype was fixed in adjacent populations.However,genetic imprints of postglacial expansions from these two sets of markers were different in the western and southeastern regions,which may result from the long-distance dispersal of the cpDNA,as well as its fast lineage sorting during intraspecific divergences.Analysis of molecular variance further suggested that genetic differentiation between the three varieties is higher at cpDNA markers than at mtDNA markers,which supports the previous viewpoint that cpDNA markers with a high rate of gene flow may be more effective in delimitating closely related taxa.Together,the results of the present study highlight the evolutionary complexity of a widely distributed species owing to interactions among local and edge expansion,long-distance dispersal,and intraspecific divergences at two sets of DNA genomes with different rates of gene flow.     

Molecular phylogeny reveals the non-monophyly of tribe Yinshanieae(Brassicaceae) and description of a new tribe,Hillielleae

The taxonomic treatment within the unigeneric tribe Yinshanieae(Brassicaceae) is controversial, owing to differences in generic delimitation applied to its species. In this study, sequences from nuclear ITS and chloroplast trn L-F regions were used to test the monophyly of Yinshanieae, while two nuclear markers(ITS, ETS) and four chloroplast markers(trnL-F, trn H-psbA, rps16, rpL32-trnL) were used to elucidate the phylogenetic relationships within the tribe. Using maximum parsimony, maximum likelihood, and Bayesian inference methods, we reconstructed the phylogeny of Brassicaceae and Yinshanieae. The results show that Yinshanieae is not a monophyletic group, with the taxa splitting into two distantly related clades: one clade contains four taxa and falls in Lineage I, whereas the other includes all species previously placed in Hilliella and is embedded in the Expanded Lineage II. The tribe Yinshanieae is redefined, and a new tribe, Hillielleae, is proposed based on combined evidence from molecular phylogeny, morphology, and cytology.     

外来植物坚尼草生态学研究

坚尼草(Panicum maximum Jacq.)是一种外来草本植物,已逸为野生,扩展迅速,对本地草本植物构成一定的影响。其扩展能力与其生长和繁殖特点有很大关系。研究表明,坚尼草对环境的适应能力较强;植株较高大,生长迅速,有较强的竞争能力;花期长,单丛坚尼草从始穗到终穗,花期可长达6～7个月;同一穗的果实熟期不同,而且边熟边脱落,从抽穗的5～7d起开始有果实脱落,脱落时间可持续1个月左右,以抽穗2～3周为脱落高峰;不同时间成熟的果实,种子萌发率也不同,7月份成熟的果实比9月份成熟的果实萌发率高。同一穗中,以抽穗后2～3周（果实脱落的高峰期）成熟的果实萌发率较高。果实成熟后,不能立即萌发,储存1～6个月,种子萌发率较高。     

外来植物坚尼草生态学研究

坚尼草(Panicum maximum Jacq.)是一种外来草本植物,已逸为野生,扩展迅速,对本地草本植物构成一定的影响。其扩展能力与其生长和繁殖特点有很大关系。研究表明,坚尼草对环境的适应能力较强;植株较高大,生长迅速,有较强的竞争能力;花期长,单丛坚尼草从始穗到终穗,花期可长达6～7个月;同一穗的果实熟期不同,而且边熟边脱落,从抽穗的5～7d起开始有果实脱落,脱落时间可持续1个月左右,以抽穗2～3周为脱落高峰;不同时间成熟的果实,种子萌发率也不同,7月份成熟的果实比9月份成熟的果实萌发率高。同一穗中,以抽穗后2～3周（果实脱落的高峰期）成熟的果实萌发率较高。果实成熟后,不能立即萌发,储存1～6个月,种子萌发率较高。     

基于ITS序列探讨杜鹃属的亚属和组间系统关系

首次报道了15种杜鹃属(Rhododendron)植物、1种杜香属(Ledum)植物和Cassiope fastigiata的内转录间隔区(ITS) (包括5.8S)序列.加上从GenBank下载的13种杜鹃属植物和Bajiaria racemosa的ITS序列,以C. fastigiata和B. racemosa为外类群,用最大简约法对杜鹃属的亚属和组间的系统关系进行了分析.结果表明: 1)杜鹃属是一个单系类群,叶状苞亚属为杜鹃属的基部类群; 2)杜香属确应归并到杜鹃属中,且与有鳞杜鹃亚属有较近的亲缘关系; 3)有鳞杜鹃亚属和杜香构成一个单系分支,该分支是其余无鳞杜鹃花的姐妹群; 4)由无鳞杜鹃花组成的一个分支的内部支持率较低,其中常绿杜鹃亚属和映山红亚属均为内部支持率很高的单系类群,而羊踯躅亚属和马银花亚属均为多系类群; 5)在马银花亚属中,长蕊杜鹃组和马银花组均分别得到强烈支持,马银花组与异蕊杜鹃亚属可能构成姐妹群关系,异蕊杜鹃亚属和马银花组组成的一个分支可能与映山红亚属构成姐妹群关系.     

薯蓣属根状茎的组织结构和萆薢类药材鉴别

应用显微镜观察了中国薯蓣属根状茎组17种1亚种1变种根状茎组织结构。结果显示,(1)根状茎均由周皮、内外侧基本组织和散生维管束组成;(2)木栓层外方常见被挤压或残留的基本组织薄壁细胞,并有木化厚壁细胞及石细胞;外侧基本组织含有散生或稀疏排列成环的粘液细胞(含草酸钙针晶束);内侧基本组织占广大部位,薄壁细胞愈近中央部位的愈大,维管束绝大部分外韧型,无形成层;(3)木质部有大型管胞或导管,管壁孔纹或网纹增厚,大形筛管易见,导管多短节状,显示了演化上的原始性;淀粉粒形态结构多样。结果表明,薯蓣属根状茎组织结构特点可作为分类依据,并显示了该组为一个自然类群。其中,药材粉萆薢(粉背薯蓣、叉蕊薯蓣)、绵萆薢(绵萆薢、福州薯蓣)的原植物根茎组织结构具有明显的鉴别意义。     

基于ITS序列探讨杜鹃属的亚属和组间系统关系

首次报道了 15种杜鹃属 (Rhododendron)植物、1种杜香属 (Ledum)植物和Cassiopefastigiata的内转录间隔区(ITS) (包括 5 .8S)序列。加上从GenBank下载的 13种杜鹃属植物和Bajiariaracemosa的ITS序列 ,以C .fastigiata和B .racemosa为外类群 ,用最大简约法对杜鹃属的亚属和组间的系统关系进行了分析。结果表明 :1)杜鹃属是一个单系类群 ,叶状苞亚属为杜鹃属的基部类群 ;2 )杜香属确应归并到杜鹃属中 ,且与有鳞杜鹃亚属有较近的亲缘关系 ;3)有鳞杜鹃亚属和杜香构成一个单系分支 ,该分支是其余无鳞杜鹃花的姐妹群 ;4 )由无鳞杜鹃花组成的一个分支的内部支持率较低 ,其中常绿杜鹃亚属和映山红亚属均为内部支持率很高的单系类群 ,而羊踯躅亚属和马银花亚属均为多系类群 ;5 )在马银花亚属中 ,长蕊杜鹃组和马银花组均分别得到强烈支持 ,马银花组与异蕊杜鹃亚属可能构成姐妹群关系 ,异蕊杜鹃亚属和马银花组组成的一个分支可能与映山红亚属构成姐妹群关系。     

中国榕属榕亚属植物的系统发育初探

对分布于中国的榕亚属植物的15个种和2个变种(分别代表榕亚属的3个组)的nrDNA的ITS序列和系统发育关系进行分析。结果表明,榕亚属是非单系起源,其中榕组构成了一个独立的单系群,与无花果亚属有较近的亲缘关系,而与榕亚属其它组间并未表现出近缘关系。榕亚属的其它5个组构成一单系群并得到中度的支持率。来自中国的种类分别聚在相应的组内。但环纹榕组被分成2个单支,其中来自中国的大叶水榕(F.glaberrima)和环纹榕(F.annulata)构成一个分支,二者表现较近的亲缘关系。榕亚属的亚洲特有组印度榕组在ITS树中聚在环纹榕组的另一个分支中,但它与此组其它种的亲缘关系并不清楚。     

五味子科的系统发育:核糖体DNA ITS区序列证据

The Schisandraceae is one of the most important taxa for understanding the origin and evolution of primitive angiosperms due to its basal position in the recent cladograms of the angiosperm based both on several gene sequences and on morphological characters, but phylogenetic relationships within the family are still unresolved. The sequences of nrDNA ITS region of 15 species representing four sections of Schisandra Michx., two sections of Kadsura Kaempf. ex Juss. and one outgroup, Illicium fargesii Finet et Gagnep., were used to reconstruct the phylogeny of Schisandraceae. Fourteen most parsimonious trees (Length=259, CI=0.934 and RI=0.889) were obtained from the analysis with I．fargesii as the outgroup. In the consensus tree, the genus Schisandra was found to be divided into three clades. Sect. Pleiostema formed a clade together with sect. Maximowiczia, sect. Sphaerostema was weakly supported to be the sister group of a clade comprising S. bicolor var. tuberculata and Kadsura species. In particular, S. bicolor var. tuberculata, a species of sect. Schisandra, was nested within Kadsura. It seems from this result and the morphological characters that Schisandra might not be a monophyletic group. According to the present molecular phylogeny, both elongated hypocarpium and deciduous habit originated independently at least twice in the Schisandraceae, and therefore, the value of the present morphological characters used in the classification of the family Schisandraceae should be reevaluated.     

Circumscription and phylogeny of Saxifraga sect. Ciliatae: Evidence from nrDNA ITS sequences

The largest section of the genus Saxifraga (Saxifragaceae), sect. Ciliatae, consists of 175 morphologically diverse species. This section is mainly distributed in the Qinghai-Tibetan Plateau and adjacent regions of southwest China and more than 80% of the total number of species are endemic to this region. It remains unknown whether this section is monophyletic and up to now no study has been conducted on the infra-sectional phylogeny. In this study, ITS sequences of the nuclear ribosomal DNA were firstly determined for 33 species mainly from this section and related sections. We further downloaded the corresponding sequences of the same DNA region for the other 22 species of Saxifraga and Mitella from GenBank. All sequences were together used to construct the phy-logenetic trees. The main implications of the phylogenetic analyses include: (1) sect. Ciliatae, as traditionally defined, constitutes as a monophyletic clade and its sister group is a well supported clade that includes species from 8 sections such as sect. Porphyrion, sect. Saxifraga and sect. Mesogyne; (2) three morphological subsections, i.e., subsect. Gemmiparae, subsect. Hirculoideae and subsect. Rosulares were tentatively recovered despite the relatively low statistic bootstrap support for the last one; however, subsect. Flagellares and subsect. Hemi-sphaericae were not recognized as separate entities, and nested within subsect. Gemmiparae; (3) subsect. Hircu-loideae and subsect. Rosulares clustered together as sister subclades while subsect. Gemmiparae diverged early. In addition, our results suggest that the paired variation of ITS sequences in sect. Ciliatae is relatively low between the sampled species in spite of their diverse morphology. It is suggested that such a scenario may mirror rapid speciation in this section that probably trigged by the uplifts of the Qinghai-Tibetan Plateau and the extensive selection pressure under the alpine environments.     

Phylogenetic analyses of various euglenoid taxa (euglenozoa) based on 18s rdna sequence data

18S rRNA genes (SSU rDNA) of five newly sequenced species were used as molecular markers to infer phylogenetic relationships within the euglenoids. Two members of the order Euglenales ( Lepocinclis ovata Playfair , Phacus similis Christen), two of the order Eutreptiales ( Distigma proteus Ehrenberg, , D. curvata Pringsheim) and Gyropaigne lefévrei Bourelly et Georges of the order Rhabdomonadales were used in parsimony, maximum likelihood, and distance analyses. All trees derived from SSU rRNA data strongly supported the monophyletic origin of the Euglenozoa, with kinetoplastids as sister clade to the euglenoids and Petalomonas cantuscygni Cann et Pennick diverging at the base of the monophyletic euglenoid lineage. The data also supported the theory that phagotrophic euglenoids arose prior to osmotrophs and phototrophs. A lineage of Peranema trichophorum Ehrenberg and all sequenced Euglenales formed a sister clade to the osmotrophs. This suggests that the evolution of phototrophy within the euglenoids radiated from a single event.     

The circumscription and phylogenetic relationships of Callitropsis and the newly described genus Xanthocyparis (Cupressaceae)

A new species of conifer was recently discovered in northern Vietnam. In a preliminary phylogenetic analysis of morphological data a possible sister species, Chamaecyparis nootkatensis (D. Don) Spach, was identified; however, because of the presumed phylogenetic remoteness of these two species to the remainder of the Cupressaceae, a new genus-Xanthocyparis-was described to accommodate both species. Here an analysis of ITS (nrDNA), matK, and rbcL sequence data in combination with 58 informative morphological characters was aimed at testing the monophyly of the remainder of Chamaecyparis and evaluating the placement and monophyly of Xanthocyparis. Chamaecyparis, minus C. nootkatensis, was resolved as a monophyletic group, remote from Cupressus and Xanthocyparis. Cupressus, Juniperus, and Xanthocyparis formed a very highly supported monophyletic group. However, Cupressus was not monophyletic. Instead the Old World species sampled were resolved sister to a clade containing a monophyletic Juniperus, a monophyletic Xanthocyparis, and a clade of New World Cupressus species. If both species of Xanthocyparis are to be treated as members of the same genus, then due to the principal of priority they will have to be recognized in the genus Callitropsis. Research is continuing to resolve the status of New World and Old World Cupressus.     

Chloroplast phylogenomics of the New World grape species (Vitis,Vitaceae)

Vitis L. (the grape genus) is the economically most important fruit crop, as the source of grapes and wine. Phylogenetic relationships within the genus have been highly controversial. Herein, we employ sequence data from whole plastomes to attempt to enhance Vitis phylogenetic resolution. The results support the New World Vitis subgenus Vitis as monophyletic. Within the clade, V. californica is sister to the remaining New World Vitis subgenus Vitis. Furthermore, within subgenus Vitis, a Eurasian clade is robustly supported and is sister to the New World clade. The clade of Vitis vinifera ssp. vinifera and V. vinifera ssp. sylvestris is sister to the core Asian clade of Vitis. Several widespread species in North America are found to be non‐monophyletic in the plastome tree, for example, the broadly defined Vitis cinerea and V. aestivalis each needs to be split into several species. The non‐monophyly of some species may also be due to common occurrences of hybridizations in North American Vitis. The classification of North American Vitis by Munson into nine series is discussed based on the phylogenetic results. Analyses of divergence times and lineage diversification support a rapid radiation of Vitis in North America beginning in the Neogene.     

基于叶绿体四个DNA 片段联合分析探讨山茶属长柄山茶组、金花茶组和超长柄茶组的系统位置与亲缘关系

为探讨山茶属茶亚属 (Camellia subgenThea) 中长柄山茶组 (sectLongipedicellata)、金花茶组 (sectChrysantha)和超长柄茶组 (sectLongissima) 的系统位置和亲缘关系,本研究选取了该属4个亚属11组28个种及2个外类群的材料,对这些材料的叶绿体4个DNA片段 (rpl16、psbA trnH、trnL F和rpl32 trnL) 进行了测序,运用邻接法 (neighbor joining)、最大简约法 (maximum parsimony) 和贝叶斯推断 (Bayesian inference) 对获得的序列进行了联合矩阵分析,并构建基因树。基因树的拓扑结构显示：1) 金花茶组包括3个平行的支系,并且长柄山茶组的模式种长柄山茶 (Camellia longipedicellata) 嵌于其中一个支系,因而金花茶组可能是一个并系或多系类群;2) 长柄山茶与越南分布的金花茶组种类在分子系统树上构成一个单系支,暗示了长柄山茶组和金花茶组之间可能具有紧密的亲缘关系;3) 超长柄茶组不是一个单系类群,该组的河口超长柄茶 (C. hekouensis) 位于系统树的基部,与山茶属其余种构成姐妹群。由于缺乏更广泛取样的分析,超长柄茶在山茶属中的系统位置仍然不明确,超长柄茶组与长柄山茶组的亲缘关系问题也没有得到解决。