中药蓼大青叶及其伪品的nrDNA ITS区序列的测定

中药蓼大青叶的基源为蓼科蓼属植物蓼蓝（Polygonum tinctorium Ait),同属植物的水蓼（辣蓼）,（P.hydropiperL.)的叶常作其伪品,本文采用PCR直接测序法,首次测定了它们的核糖体DNA ITS区序列,结果显示,两者充列长度（ITS1,5,8S,ITS2）均为646bp,序列间共有28个变异位点,本研究为产蓝植物的DNA分子鉴定提供了必要的序列资料。     

新疆石竹属野生种核糖体DNA的ITS序列与亲缘关系

新疆是我国石竹属植物分布和分化中心,种质资源丰富。通过采用PCR直接测序法,对新疆石竹属（Dianthus)植物野生种共8个种及外类群（Lychnis coronata Thunb)rDNA的ITS区（包括ITS－1,5.8S,rDNA和ITS－2）进行序列测定。研究结果说明,新疆石生属植物的ITS序列总长度为617－621bp,长度变异较小,仅相差4bp,种间序列同源性很高,达97．6％－99．8％,外类群的序列同源性为80％左右。ITS区序列在石竹属内是相当保守的,石竹属物种间序列变异位点基本上是转移多于颠换,且转移率较高,转换／颠换率为1．0－3．0。系统地位和亲缘关系分析表明分布于中国的石竹属植物3个组即齿瓣组（sect.Barbulatum Williams)和石竹组（sect.Dianthus),遂瓣组（sect.Fimbriatum Williams)的亲缘关系较远,而sect.Dianthus与sect.Fimbriatum Williams的亲缘关系较近。ITS系统发育树揭示了石竹组起源早于遂瓣组和齿瓣组,其结果与传统形态学论述存在很大差异。     

中国苋属nrDNA的ITS序列分析及其系统学意义

运用ＰＣＲ直接测序法,对苋属（Ａｍａｒａｎｒｈｕｓ Ｌ．）１５个种及外类群鸡冠花（Ｃｅｌｏｓｉａ ｃｒｉｓｔａｔａ Ｌ．）ｎｒＤＮＡ的ＩＴＳ区（包括ＩＴＳ－１,５．８５ｒＤＮＡ和ＩＴＳ－２）进行序列测定。结果表明苋属植物的ＩＴＳ序列总长度为６２９－６３２ｂｐ,长度变异仅发生在ＩＴＳ－１区（２５０－２５３ｂｐ）。采用ＰＡＵＰ软件进行系统发育分析表明：分布于中国的苋属植物可分为３组,即刺苋组（ｓｅｃｇ     

核糖体DNA ITS区序列在植物分子系统学研究中的价值

本文就近年来国内外有关被子植物核糖体ＤＮＡ中的内转录间隔区（ＩＴＳ）序列在植物属内,近缘属间乃至科内系统发育研究中的应用,结合作者在中国姜科山姜属（Ａｌｐｉｎｉａ Ｒｏｘｂ．）上的研究,对ＩＴＳ区序列在植物分子系统学研究中的价值作一简要综述,对其应用前景也进行了讨论。     

应用ITS区序列对秋海棠属无翅组分类学问题的探讨

以侧膜组（Sect.Coeloecentrum)的Begonia cirrosa和单裂组（Sect.Reichenheimia)的B.henryi为外类群,对秋海棠属（Begonia L.)无翅组（Sect.Sphenanthera)9种2变种及秋海棠组（Sect.Begonia)4种进行了ITS区（包括5.8s rDNA)序列的测定。发现该属的ITS序列较一般类群要长一些,所测的序列长度变化范围为648－743bp。这些序列经Clustal X软件排序后序列总长为756个位点,gap做缺失处理时,变异位点和信息位点分别占26.41%和10.11%。运用PAUP4.0b8软件分析,获得6棵最大简约树,步长为286,一致性指数（CI）和维持性指数（RI）分别为0.8287和0.7841,利用6棵最简约树获取严格一致树,并作Bootstrap检测。结果表明：1.支持将原无翅组内子房3室的种类移入秋海棠组,而将子房4室的种保留,成立四室组（Sect.Sphenanthera);2.将B.tetragona作为B.acetosella的异名处理得到一定的支持;3.B.crassirostris的系统位置有待进一步的研究。     

用nrDNA ITS序列探讨狭蕊龙胆属及其近缘属 (龙胆科)的系统发育

运用核糖体DNA内转录间隔区ITS序列对狭蕊龙胆属Metagentiana10种及其近缘属22种植物进行了系统发育分析。ITS分析结果表明狭蕊龙胆属是一个多系群:在系统发育树上,双蝴蝶属Tripterospermum和蔓龙胆属Crawfurdia的种类位于狭蕊龙胆属各分支中,而且双蝴蝶属和蔓龙胆属的种类也相互交叉;这一结果不支持将3个属各自独立为属。但是,在所有分析中,3个属共同形成一单系分支,是龙胆属Gentiana的姊妹群;这一结果与形态学、花部解剖学、细胞学、孢粉学和胚胎学等证据基本一致,狭蕊龙胆属应该从龙胆属中分离出来,它与双蝴蝶属和蔓龙胆属有更为密切的亲缘关系。根据分支图,在狭蕊龙胆属、双蝴蝶属和蔓龙胆属组成的复合群中,现已知的染色体基数x＝17、21和23可能存在网状和平行进化。     

根据核DNA的ITS序列的RFLP分析鉴定稻属CD染色体组物种

稻属物种的染色体组类型有10种,其中具CD染色体组的物种有3种(Oryza alta Swallen,O.grandiglumis(Doell)Prod.和O.latifolia Desv.),仅分布在美洲中部和南部.这3个种在形态上和稻属其他染色体组的种比较容易区别,但它们彼此之间鉴别比较困难.近年来的研究表明,O.alta和O.grandiglumis应归并为1个种(O.grandiglumis),而O.latifolia应保持不变.本文基于代表不同分布区11个样品的核糖体转录间隔区(ITS)的77个克隆序列数据,利用DNA Striderl.2软件进行了限制性酶切位点分析,提出了一个鉴别CD染色体组物种的方法.方法的具体步骤是:(1)用通用引物扩增ITS片段;(2)用特异性的限制性内切酶Fok Ⅰ和/或Dra Ⅲ消化PCR扩增产物;(3)用1%的琼脂糖电泳并根据消化产物的多态性特征来鉴别不同物种.基于本文提出的核糖体ITS限制性片段多态性(RLFP)分析,可以快速和可靠地将稻属CD染色体组物种区别开来.     

衣藻属的系统发育分析——基于形态形状和nrDNA ITS序列

通过实验分析莱茵衣藻 ( Chlamydomonas reinhardtii) 1个种和互连网获得衣藻属 1 5个种及丝藻属 1个种 ( Ulothrix zonata) ,共 1 7个种的 nr DNA ITS序列 ,并以 U.zonata为外类群 ,采用计算机分析软件包对其进行分析及构建分子系统发育树图。同时以 1 2个传统分类性状 ,对此 1 6种衣藻构建数据矩阵 ;以 U.zonata动孢子的相应性状为外类群原始性状 ,用Wagner法在计算机上对其进行分枝分析 ;然后比较并分析分子系统树和表征性状分支分析树的异同。初步尝试以 ITS分子序列系统发育分析作为传统性状分析的补充来研究衣藻种间的亲缘关系。     

草豆蔻传粉生物学的研究

比较研究了花柱卷曲性植物草豆蔻 Alpinia hainanensis两种表型(上举型和下垂型)的传粉生物学特性。结果表明:草豆蔻的花柱卷曲运动节律与其他已报道的山姜属Alpinia植物基本一致,而下垂型花的花柱卷曲运动明显滞后于上举型花约2 h。草豆蔻的花柱卷曲运动中存在一些不同步的现象,甚至在同一花序上的两朵花的花柱运动节律亦会表现出不一致的现象,但上举型花的花药开裂时间却严格同步,都发生在同类型个体的柱头全部位于花药上方之后进行。草豆蔻上举型花的花蜜分泌量、单花花粉量、花粉/胚珠比率(P/O)均明显比下垂型花多,而两种表型的胚珠数、花蜜糖含量、氨基酸含量无显著差异。在草豆蔻的单花期内不同时间段进行人工授粉,上举型花在其柱头位于花药下方时进行人工授粉,其结实率明显比柱头位于花药上方时人工授粉的处理高,下垂型花则没有显著差异。在自然居群中,草豆蔻的主要传粉者是无垫蜂Ameglla sp.和两种木蜂Xylocopa sp.,但存在传粉者不足而影响结实率的现象。完全套袋、去雄和去雌(去柱头)处理的均不结实,表明草豆蔻中不存在无融合生殖、主动自花授粉和滞后自交的生殖保障现象。而人工自交和异交均具有较高的结实率,表明草豆蔻为自交亲和植物。草豆蔻的繁育系统是具花柱卷曲性运动的异花授粉的交配系统。     

Camellia nitidissima与C.petelotii之间的关系研究——来自nrDNA ITS的证据

通过对 Camellia nitidissima Chi和 Camellia petelotii (Merr.) Sealy的核糖体 DNAITS区序列进行分析 ,结果表明两者的 ITS区序列存在一定的差异 ,Camellia nitidissima与Camellia tunghinensis,Camellia limonia和 Camellia pingguoensis的亲缘关系比与 Camelliapetelotii的关系更近 ,说明两者是相互独立的种。     

Molecular phylogeny and divergence times of Onosma (Boraginaceae s.s.) based on nrDNA ITS and plastid rpl32‐trnL(UAG) and trnH–psbA sequences

We analysed 87 species of Onosma (Boraginaceae) from throughout its distribution range to investigate its evolutionary history. Using nrDNA ITS and two plastid (rpl32‐trnL_(UAG) and trnH–psbA) markers, we reconstructed phylogenetic relationships within Onosma by conducting maximum parsimony, maximum likelihood, Bayesian, and BEAST analyses. The analyses revealed that Onosma as currently circumscribed is not monophyletic. However, the vast majority of Onosma species appear to belong to a single clade, the so‐called Onosma s.s. Outside of this core clade is a clade containing O. rostellata, a subclade of Sino‐Indian species and Maharanga emodii. Podonosma orientalis (as O. orientalis) appear only distantly related to Onosma but is more closely related to Alkanna, as also suggested in previous molecular studies. The Onosma s.s. clade includes all representatives of O. sect. Onosma, and encompasses three subsections, i.e. Onosma, Haplotricha and Heterotricha, corresponding to asterotrichous, haplotrichous and heterotrichous groups, respectively, but none of these subsections was retrieved as monophyletic. We observed significant incongruence between nuclear and chloroplast phylogenies regarding the phylogenetic status of the heterotrichous group. A dozen of the Iranian haplotrichous species formed a lineage which may not hybridize with asterotrichous species. Divergence time estimates suggested that the early radiation of Onosma s.l. took place at the Oligocene‐Miocene boundary and the diversification within Onosma s.s. occurred during middle to late Miocene and Pliocene.     

Phylogenetic analysis of Eremurus,Asphodelus, and Asphodeline (Xanthorrhoeaceae-Asphodeloideae) inferred from plastid trnL-F and nrDNA ITS sequences

The current study represents phylogenetic analyses of Eremurus, Asphodelus and Asphodeline (Xanthorrhoeaceae-Asphodeloideae) using both plastids genome (trnL-F) and the nuclear ribosomal internal transcribed spacer (nrDNA ITS) sequence data. The analyses revealed that each of the investigated genera is monophyletic. Eremurus subgenus Eremurus is monophyletic, whereas the E. subgenus Henningia is paraphyletic. Trachyandra is the closest relative of Eremurus. Bulbinella and Kniphofia are subsequent sisters of Eremurus and Trachyandra. Aloe, Haworthia and Bulbine were nested in a single clade, sister to the last four genera. Asphodeline section Asphodeline appeared to be non-monophyletic, because of the inclusion of A. damascena. All species of Asphodelus analyzed herein, formed a well-supported clade that it is sister to the clade of Asphodeline species.     

基于ITS序列探讨珍珠菜属过路黄组的系统关系

测定了紫脉过路黄、临时救和过路黄的nrDNA ITS序列,并分析了珍珠菜属过路黄组17个物种的遗传距离及亲缘关系。结果表明,过路黄组植物的ITS序列长度在620～628间,一致性高达90.59%,种间遗传距离为0.002～0.199。系统发育树表明:(1)紫脉过路黄、临时救和小茄亲缘关系较近;(2)大叶过路黄、落地梅和过路黄亲缘关系较近;(3)山萝过路黄、贯叶过路黄、管茎过路黄、叶头过路黄、峨眉过路黄及三角叶过路黄亲缘关系较近。ITS序列分析结果为组内植物的鉴定、分类及系统进化提供了新的参考。     

Molecular authentication of Anthemis deserti Boiss. (Asteraceae) based on ITS2 region of nrDNA gene sequence

The dried plant material of medicinally important Anthemis deserti Boiss. (family: Asteraceae) especially when it remains in the powdered form often look similar to Anthemis melampodina Del.; and therefore, difficult to distinguish, finally lead to chances of adulteration. The adulteration in medicinal plants effects on the efficacy of the drugs. The molecular authentication of herbal plant materials such as based on the internal transcribed spacer 2 (ITS2) sequences of nuclear ribosomal DNA (nrDNA) is considered as more reliable method compared to other the biochemical or histological methods. The present study aims to molecular authentication ofA. deserti based on molecular phylogenetic analyses of ITS2 gene sequence of nrDNA region. The ITS2 region of nrDNA of A. deserti were sequenced, and the molecular phylogenetic analyses were performed together with the GenBank sequences. The Maximum Parsimony tree revealed the close relationships of A. deserti with A. melampodina; however, the Neighbor-Joining and Maximum Likelihood tree clearly revealed that A. deserti is distinct from A. melampodina, which is also supported by the differences in nucleotides at five diffident positions (i.e. 22, 28, 87, 175 and 198) in the DNA sequence alignment.     

云南草蔻和长柄山姜挥发油的化学成分分析

云南草蔻（Alpinia blepharocalyx K．Schum．）和长柄山姜（A．kwangsiensis T．L．Wu et Senjen）均为姜科山姜属多年生草本植物。云南草蔻,又名小草蔻,产自云南南部及西部,生于海拔100～1000m的疏林中;长柄山姜主要分布在广东、广西、贵州和云南,生于山谷中林下阴湿处,海拔580～680m。云南草蔻是傣药品种之一,种子以草豆蔻之名入药,根茎则用于治疗腹胀、腹部冷痛;长柄山姜根茎可治脘腹冷痛、胃寒呕吐。到目前为止,有关云南草蔻和长柄山姜根茎挥发油成分的研究尚未见报道。     

基于ITS和matK序列的兰科沼兰族分子系统研究及二新种

沼兰族是兰科植物的大族之一,约2000种,除了极地和沙漠地区,全球均有分布.该族植物主要分布在热带地区,尤其在东南亚、热带美洲、非洲以及澳大利亚等地区种类非常丰富.目前,已有关于该族植物形态和分子系统的研究,但有关该族亚族和属间的系统关系尚不清楚,属的界定争议也较大.该文基于核基因片段 ITS 和叶绿体基因片段 mat K 序列,采用最大简约法、最大似然法贝叶斯推理分析法,对现有沼兰族主要属的123种植物和10个外类群植物进行了分子系统学研究.结果表明：沼兰族主要分为3个亚族分支,包括附生的鸢尾兰亚族(Oberoniinae)、地生的羊耳蒜亚族(Liparidinae)和沼兰亚族分支(Crepidium clade).鸢尾兰亚族包括6个属、羊耳蒜亚族分支包括5个属、沼兰亚族分支包括4个属;丫瓣兰亚族(Ypsilorchidinae)应归并为鸢尾兰亚族;Disticholiparis 属与 Stichorkis 属的模式标本相同,应并入 Stichorkis 属;沼兰属(Cre-pidium )和无耳沼兰属(Dienia )的唇瓣结构差异较大,但二者均为单系类群.此外,在收集野外实验材料过程中,发现了2种产自中国西南部和越南北部的沼兰族新种,分别命名为麻栗坡羊耳蒜(Platystyliparis mali-poensis G．D．Tang,X．Y．Zhuang & Z．J．Liu)和秉滔羊耳蒜(Cestichis pingtaoi G．D．Tang,X．Y．Zhuang &Z．J．Liu).     

A phylogenetic study ofSaxifraga sect.Saxifraga (Saxifragaceae) based on nrDNA ITS sequences

Parsimony analyses of 54 nrDNA ITS (Internal Transcribed Spacer) sequences ofSaxifraga sect.Saxifraga were performed. In addition to some unresolved clades, there is strong disagreement between the ITS phylogeny and previous classifications based primarily on morphology. The extensive cytological instability of sect.Saxifraga prevents previous cytotaxonomical results from resolving the incongruence between molecular and morphological data. Dissimilar topologies between chloroplast (matK) and nuclear (ITS) trees for eight species of sect.Saxifraga suggest that gene trees and the true species tree are not coincident. Recent and mid-term reticulation is proposed as an explanation for the incongruence between morphological, cytological, organellar, and nuclear data. Homogenization in multigene families, such as the ITS region, via concerted evolution may be the key to the interpretation of results based on ITS sequences within sect.Saxifraga. The use of organellar genes in a larger sample should help to determine whether extensive reticulation occurs in sect.Saxifraga, as has been documented in various genera of Saxifragaceae.