报春花属藏报春组、毛莨叶报春组的界定和系统发育关系：核糖体DNAITS序列证据

报春花属（PrimulaL.)藏报春组（sect.Auganthus Pax ex Balf.f.)和毛莨叶报春组（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DNAITS序列数据探讨其系统发育关系。取样包括藏报春组和毛莨叶报春组的全部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.)和野藏报春耕（P.rupestris Balf.f.et Farrer)一起置于藏报春组;毛莨叶报春组只含两种;毛莨叶报春（P.cicutariifoliaPax)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。     

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.     

虎耳草属山羊臭组的界定和系统发育: 核糖体DNA ITS序列证据

虎耳草属Saxifraga山羊臭组sect. Ciliatae是该属中最大的一个组, 共有175种, 主要分布在喜马拉雅地区, 我国分布有166种, 占总种数的95%; 其中, 112种为中国特有。约80%的种类分布在我国青藏高原和西南地区, 是中国喜马拉雅植物成分的代表类群。山羊臭组内物种分化十分显著, 分类处理也很困难, 该组是否为单系类群, 组下的系统发育关系也不清楚, 均需进一步验证。本文测定了虎耳草属山羊臭组及其他组33种植物样品的核糖体DNA内转录间隔区ITS序列, 并从GenBank调取虎耳草组sect. Saxifraga等组和近缘属唢呐草属Mitella共22种植物的该序列。ITS分析结果表明: (1)所研究的山羊臭组类群聚为单独一支, 而且与垫状组sect. Porphyrion、虎耳草组、球茎组sect. Mesogyne和仅在欧洲分布的sect. Cymbalaria和sect. Cotylea等8个组聚成的另一分支构成姊妹群; (2)根据形态特征建立的山羊臭组的3个亚组即唐古拉亚组subsect. Hirculoideae、莲座状亚组subsect. Rosulares和具芽亚组subsect. Gemmiparae各自聚为一支, 但是莲座状亚组这一支的支持率较低。同时, 山羊臭组的鞭匐枝亚组subsect. Flagellares和subsect. Hemisphaericae的代表类群单独聚为一支, 位于具芽亚组类群分支内部而不能成立; (3)唐古拉亚组和莲座状亚组又聚为一亚分支与具芽亚组构成姊妹群, 而且具芽亚组最早从山羊臭组这一支中分化出来。我们的研究还发现山羊臭组内种间形态分化较大, 而ITS碱基变异较小, 这可能是山羊臭组类群在青藏高原及毗邻地区的高山环境下物种快速分化的结果。     

基于ITS序列的苎麻属大叶苎麻组的系统发育研究

大叶苎麻组(Sect.Duretia)是荨麻科苎麻属(Boehmeria)的一个种类比较多的组,目前对该组植物的系统发育还不清楚.本研究测定了其中9种4变种的核糖体DNA的ITS序列.ITS平均长度约687 bp.选取冷水花属作为外类群,根据ITS序列的差异计算出种间遗传距离.分别采用最简约法和邻接法进行系统发育分析.细野麻(Boehmeria gracilis)、赤麻(B.silvestrii)、野线麻(B.japonica)和疏毛水苎麻(B.pilosiuacula)、束序苎麻(B.siamensis)亲缘关系较近聚成一支,自展支持率为76%(MP)和89%(NJ);密球苎麻(B.densiglomerata)、长序苎麻(B.dolichostachya)、灰绿水苎麻(B.macrophylla var.canescens)、糙叶水苎麻(B.macrophylla var.scabrella)、圆叶水苎麻(B.macrophylla vat.rotundifolia)和海岛苎麻(B. formosana)、福州苎麻(B.formosana var.stricta)则聚为另一支,自展支持率为74%(MP)和94%(NJ);歧序苎麻(B.polystachya)单独为一支,与大叶苎麻组的其他种在一级分支中就分开,和其他种亲缘关系较远.     

云南报春花属(报春花科)一新变种--长萼铁梗报春

报道了云南报春花属一新变种,即长萼铁梗报春Primula sinolisteri Balf．f．var．longicalyx D．W．Xue＆C．Q．Zhang。新变种与原变种的不同之处在于：花冠喉部具环状附属物,外面无毛,花萼与冠筒近等长,长7—10mm。     

安徽羽叶报春和毛茛叶报春的微形态特征

在扫描电子显微镜和光学显微镜下,观察了安徽羽叶报春(Primula merrilliana Schltr.)与毛茛叶报春(Primula cicutariifolia Pax)的种子、花粉形态及表面纹饰与叶表皮形态结构.结果表明:2种类的种子都呈不规则七面体或多面体,多具五边形纹饰;安徽羽叶报春的种皮雕纹浅,网眼具许多小的乳头状突起;毛茛叶报春的种皮雕纹明显,网眼粗糙,具许多大的乳头状突起.2种类花粉均为球形,具散孔(孔数达10个以上),具网状雕纹.2种类的叶表皮细胞呈凹凸镶嵌状不规则排列,而在中脉处呈长方形或略带微波状长方形,上表皮细胞稍大;叶两面被腺毛,且顶端具水孔.气孔的分布属于偏叶下表面生长,在边缘处尤密,而在中脉处近无;相对而言,安徽羽叶报春的气孔略比毛茛叶报春的气孔小,且密度也低;电子显微镜下2种类的气孔外拱盖内缘光滑,保卫细胞外缘隆起明显,中间凹陷,其上着生的乳头状突起安徽羽叶报春不如毛茛叶报春明显.     

毛茛叶报春组一存疑种花粉形态的多样性研究

对分布于浙江西北部的毛茛叶报春组(sect. Ranunculoides)一存疑种5个居群共50个植株的花粉形态进行了研究观察。结果表明该存疑种的花粉形态特征在种下具高度多样化,根据萌发孔类型、数量及组成的不同,其花粉可划分为多沟型、沟多孔少型、孔多沟少型、散孔型和环沟型5种类型;而且居群间花粉的大小及花粉类型的组成也存在较大的差异;此外,同一个植株或同一个花粉囊的花粉也可能具有多种类型的花粉。本文进一步证明了花粉形态特征在种内可能存在多样化的现象。花粉形态特征支持该存疑种为一个独立的新物种,它很可能是由具多沟型和散孔型花粉的亲本杂交进化而来。     

栝楼属基于核糖体ITS序列的系统发育分析

栝楼属（Trichosanthes）是葫芦科(Cucurbitaceae)中一个种类较多、药用价值较大的属。本文基于ITS序列分析了栝楼属16个种的系统发育关系。聚类分析表明：在组的划分上,具有分类争议的截叶组(sect. Truncata)与大苞组(sect. Involucraria)形成一大支,处于一亚分枝位置,不支持独立成组。在属内分类地位上,在核酸水平不支持贵州栝楼(T.guizhouensis)为一独立种,结合形态特征建议并入双边栝楼(T.rosthornii)。大方油栝楼(T.dafangensis)与小苞组(sect. Trichosanthes)成为姊妹群,处于一个向叶苞组(sect. Foliobracteola)过渡位置,结合其形态特征,建议作为小苞组(sect. Trichosanthes)成员。     

中国特有濒危种川东灯台报春(报春花科)的重新发现

2006年6月份和9月份,作者在对重庆市城口县大巴山地区进行考察时,采集到了中国特有种川东灯台报春（Primula mallophylla）的标本,这是近百年来对该种除模式标本外的再度发现。根据在大巴山观察及采集到的材料,作者对过去该种的特征描述中存在的一些疑问进行了澄清,更正和补充了其形态描述;对历史上混淆的几个种列出了检索表;报道了该种的染色体数目及核型;根据国际通用的“红色名录等级及标准”对其濒危等级进行了评估。     

基于叶绿体trnL-F,rbcL序列和核核糖体ITS序列探讨蓼属（蓼科）头状蓼组的系统发育

选用叶绿体基因trnL-F,rbc-L序列和核核糖体ITS序列对蓼属头状蓼组的分类和系统发育进行了分析。以药用大黄为外类群,用最大简约法对3个片段的单独和联合矩阵分别构建系统发育树。结果表明,头状蓼组是一个较自然的类群,与春蓼组、刺蓼组和金线草属的亲缘关系较近;支持头状蓼组作为一组放在春蓼属,细茎蓼和蓝药蓼从头状蓼组转移至冰岛蓼属;不支持将刺蓼组并入头状蓼组;对于小叶蓼的系统学位置有待于进一步研究。     

Circumscription of Primula subgenus Auganthus (Primulaceae) based on chloroplast DNA sequences

Recent molecular phylogenetic analyses of Primula have greatly enhanced our understanding of the infrageneric relationships of the genus,but the subgenera Auganthus and Carolinella remain meagerly sampled and poorly understood.In the present study,nucleotide sequence data of three chloroplast DNA regions (matK,rps16,and trnL-F) were used to infer phylogenetic relationships of the subgenera Auganthus and Carolinella.Sequence data were acquired and analyzed for 70 species of Primula and its close relatives.Th...     

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.     

基于核糖体DNA内转录间隔区ITS序列的广义蓼属及近缘属分子系统学研究

通过对广义蓼属及近缘属共32个代表种内转录间隔区ITS序列的分子系统学分析,尝试研究备受争议的广义蓼属及近缘属的物种族、属、组级的划分问题,结果显示,广义蓼属在系统发育树上并不能形成一个单系类群,这些物种共聚为3大支,分别对应春蓼族、蓼族及荞麦族,其中荞麦属与翅果蓼属形成了一支独立于春蓼族及蓼族之外的类群。在春蓼族中,冰岛蓼属与分叉蓼组形成一个单系类群。     

Phylogenetic Analysis of the Sonneratiaceae and its Relationship to Lythraceae Based on ITS Sequences of nrDNA

Lagerstroemia nested within the Sonneratiaceae. The Sonneratiaceae occurred within the Lythraceae with high bootstrap value support (96%). The two traditional genera constituting Sonneratiaceae were in different well-supported clades. Duabanga (Sonneratiaceae) is sister to the clade of Lagerstroemia (Lythraceae) (82%). The mangrove genus Sonneratia (100%) formed the other monophyletic group. It was located terminally within the Lythraceae clade and comprised two clades: one consisting of S. apetala, S. alba, S. ovata, and S. hainanensis; the other including S. caseolaris and S. paracaseolaris. The results indicated that species previously placed in two different sections (Sect. Sonneratia and Sect. Pseudosonneratia) of Sonneratia occurred within the same clade, and the taxonomic classification was not supported by the molecular analysis of the ITS region sequences. Based on the phylogenetic analyses of the ITS regions, the Sonneratiaceae were shown to be nested within the family Lythraceae. Therefore, the sequence data presented here do not support the recognition of the Sonneratiaceae as a distinct family, but instead support the inclusion of Sonneratiaceae in the Lythraceae proposed by other authors. Received 27 December 1999/ Accepted in revised form 25 June 2000     

Phylogenetic relationships and character evolution in Primula L.: The usefulness of ITS sequence data

ABSTRACT

The main goals of this research were to reconstruct the infrageneric phylogeny of the genus Primula based on both nuclear and chloroplast DNA sequences, and to use the resulting phylogenies to elucidate the evolution of breeding systems, morphological characters, chromosome number, and biogeographic distribution in the genus. In this paper, the results of a pilot study based on the nuclear ribosomal Internal Transcribed Spacer (ITS) region are described. ITS sequences from 21 taxa produced a number of variable characters sufficient to resolve relationships among sections. The resulting phylogeny confirmed the monophyly of sections Auricula and Aleuritia. Sections Armerina, Proliferae, Crystallophlomis, Parryi, and Auricula, with a base chromosome number of x = 11, and sect. Aleuritia, with a base chromosome number of x = 9, formed two well supported clades. The ITS topology also suggested that leaves with revolute vernation, previously believed to be a derived state, might represent the ancestral condition in Primula, with later reversals to the involute condition. Finally, this initial ITS tree provides preliminary support to the proposed role of the widespread, diploid and heterostylous P. mistassinica as having given origin to the polyploid, homostylous P. incana and P. laurentiana.     

基于ITS序列探讨金线草的系统学位置

金线草的系统位置一直存在争议,该试验以Triplaris weigeltiana为外类群,采用最大简约法对金线草及其近缘类群的ITS序列进行了系统发育分析.结果表明:(1)金线草和蓼属的春蓼组、刺蓼组形成三个并列的分支,因此,金线草没有必要独立成属,分子证据支持金线草成立为组;(2)金线草和春蓼组、刺蓼组植物聚在一起,...     

基于ITS序列分析仲彬草属植物的亲缘关系

以旱雀麦为外类群,用PAUP 4.0b10软件并采用最大简约法和邻接法对11份仲彬草属物种的ITS区序列进行系统发育分析,两种方法得到的系统发育树基本一致。结果表明:(1)整个ITS序列长度变异范围为596~601 bp;G C含量在所有ITS中的变化范围为61.20%~62.44%;序列间的遗传分化距离为0.003~0.033,平均值为0.015;(2)疏花仲彬草和塔克拉干仲彬草2个物种聚为一支,位于系统发育树的底部,在最大简约法和邻接法分析中分别获得78%和82%的自展支持率,它们之间的亲缘关系较近;(3)形态相似、地理分布一致的物种有聚在一起的倾向,表现出较近的亲缘关系;(4)ITS区序列分析的结果与细胞学、形态学的研究结果基本一致,因此ITS区序列分析能反映仲彬草属种间关系。