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1.
岳麓紫菀(Aster sinianus Hand. Mazz.,菊科紫菀族)为多年生草本,特产于中国湘赣毗邻地区。在对其整个分布区进行野外采集和生境观察时,发现了2个新的分布地点,同时确认其已在模式产地湖南省长沙市岳麓山灭绝。该研究将岳麓紫菀从浏阳市沙市镇回迁至岳麓山,以期恢复模式产地的居群。形态学研究表明,现有文献对该种的描述多处不准确,如对基生叶、株高、茎下部叶、托片和海拔等的记载。基于形态性状,讨论了岳麓紫菀的系统学地位,并首次报道了该种的核型特征:岳麓紫菀为二倍体,核型为2n=2x=16m+2m(SAT),属于1A型。该研究结果为岳麓紫菀的分类地位的修订和物种保护提供了重要的资料。  相似文献   

2.
菊科紫菀属密毛系(Aster Series Vestiti Ling)含3个物种:密毛紫菀(A.vestitus Franch.)、灰枝紫菀(A.poliothamnus Diels)和西固紫菀(A.sikuensis W.W.Smith et Farr.),新近的分子系统学研究对密毛系是否单系提出质疑。该文采用常规根尖压片法,对紫菀属密毛系3种植物4个居群的核型进行观察分析。结果显示:3种植物的核型公式均为2n=2x=18=14m+4sm(2SAT);密毛紫菀居群2个的核型属于1A型,灰枝紫菀和西固紫菀为2A型。密毛紫菀和西固紫菀的核型资料为首次报道。灰枝紫菀的染色体数目、基数和不对称性等核型资料与先前唯一的相关报道结果(体细胞染色体数目为32,核型公式2n=2x=32=26sm+6st,属4A型,染色体中未发现随体)迥然不同。3种植物的核型结果不支持保留密毛系,而核型不对称性类型支持该实验室先前提出的亚属划分。3种植物随体的大小属于紫菀亚族型,这支持欧亚紫菀属与北美紫菀类没有密切亲缘关系的观点。  相似文献   

3.
产自湖北神农架的狭叶三脉紫菀Aster ageratoides var. gerlachii (Hance) Chang一直被各种文献和有关标本馆误定为小花三脉紫菀A. ageratoides var. micranthus Ling。我们对二者进行了野外采集和形态学、细胞学的比较研究,分析了导致错误鉴定的原因,重新确定了二者的界限。小花三脉紫菀无横走地下茎,这一性状具有重要的分类学价值。核型研究发现,小花三脉紫菀为二倍体,2n=2x=18=18m,核型属1A型;狭叶三脉紫菀则是四倍体,2n=4x=36=32m+4sm (2SAT),核型属2A型。二变种的染色体数目、核型均为首次报道。狭叶三脉紫菀在湖北为新分布记录。  相似文献   

4.
菊科紫菀属横斜系(Asterseries Hersileoides Ling)特产于中国,含横斜紫菀(Aster hersileoides Schneid.)和亮叶紫菀(A.nitidus Chang)2个狭域分布种。细胞学研究表明,横斜紫菀和亮叶紫菀均为二倍体,染色体较小,长度在1.64~2.8μm之间,核型公式为2n=2x=18=16m+2sm,属1A类型。横斜紫菀和亮叶紫菀的染色体数目和核型为首次报道。  相似文献   

5.
湖南紫菀属(菊科)一新变种--垂茎三脉紫菀   总被引:1,自引:0,他引:1  
报道了湖南紫菀属Aster一新变种——垂茎三脉紫菀A.ageratoides var.pendulus W.P.Li&G X.Chen。新变种与宽伞三蔓脉紫菀A.ageratoides var.laticorymbus(Vant.)Hand.-Mazz.最为接近,但以如下特征与之相区别:茎下垂,基生叶和茎下部叶背面常为紫色,茎生叶常条形,叶上面被糙毛,总苞片较宽。新变种因叶常条形和舌状花白色而与小花三脉紫菀A.ageratoides var.microanthus Ling相似,但总苞片顶端旱绿色,1.25-1.75mm宽,具明显横走地下茎而不同。  相似文献   

6.
结合模式产地采集的长柄马兰(Aster longipetiolatus C.C.Chang)标本以及查阅相关文献资料,发现已有的形态描述不充分且缺乏细胞学方面的报道。本研究对长柄马兰的形态特征进行补充描述和核型分析,为探讨其分类地位提供资料。结果包括:①发现并补充长柄马兰新的形态特征:花序托凸起、总苞片3~4层、舌状花具有退化雄蕊、舌片具柔毛、瘦果5肋。②细胞学结果表明,长柄马兰的染色体数目为2n=18,核型公式为2n= 18=16m+2sm,核型属于1A。  相似文献   

7.
三峡库区川鄂紫菀(菊科)的形态学和细胞学研究   总被引:5,自引:1,他引:4  
对川鄂紫菀(Aster moupinensis (Franch.)Hand.-Mazz.)秭归居群进行了形态学和细胞学研究。形态学研究表明,川鄂紫菀存在居群间分化,但不足以划分变种。发现了一些被以前研究者忽视的重要性状,首次报道了川鄂紫菀的染色体数目和核型。其核型公式为2n=2x=18m。  相似文献   

8.
广义的紫菀属(Asters.l.)曾是个大包大揽的类群,产于北美和欧亚大陆.Nesom主要根据瘦果的形态和细胞学性状对Asters.l.进行了评价,将北美紫菀类植物从Aster中独立出去,使Aster成为欧亚特有类群.但是,在欧亚各国对Aster有定为一属和分为十多个属等不同的分类学处理,分歧较大.狭义紫菀属(Asters.s.)与从Asters.l.中分出的各属之间的系统学关系,以及后者中某些属与北美紫菀类和紫菀族其他亚族间的系统学关系,都存在很大疑问.过去一直认为北美是Aster的发源地,现在欧亚Asters.l.的起源与演化需要重新研究,而青藏高原是探讨Asters.l.物种多样性形成的关键地区.DNA尤其是DNA序列资料在研究Asters.l.的系统发育和分类上将发挥关键作用.  相似文献   

9.
文章报道了发现于南昌的中国菊科植物一新归化属种——软金菀属(Bradburia Torr.&A.Gray)和柔毛软金菀(新拟)[B.pilosa(Nutt.) Semple]。基于核基因(ITS)构建的系统发育树确定了软金菀属的系统发育位置,即与金菀属[Chrysopsis(Nuttall) Elliot]互为近缘属。与金菀属相比,该属的主要特征为茎具柔毛或糙毛,基生叶具柄或近无柄,头状花序单生。柔毛软金菀与该属其他种相比,主要特征为植株密被柔毛,基生叶宿存且近无柄,舌状花和管状花均具2层冠毛且内层冠毛的长度是外层冠毛的5~10倍。该种最初于2015年在南昌市昌北机场出现,可能由临时经停此处的北美一航班携带而来,2022年底已经扩散到15 km外的经济技术开发区,呈现明显入侵态势。  相似文献   

10.
该文描述了在中国福建北部山区茫荡山发现的菊科(Compositae)紫菀属(Aster L.)一新种——香紫菀(A.artemisiaodorum X.X.Su,S.P.Chen&L.Ma sp.nov.)。基于2个核基因(ITS、ETS)和1个叶绿体基因(trn L-F)片段构建的系统发育树显示,香紫菀具有独立性,与白舌紫菀[A.baccharoides(Benth.)Steetz]互为姐妹类群,但该种形态与白舌紫菀相差较大,其全部叶两面无毛、总苞筒状、头状花序1.0~1.8 cm、舌状花5~8朵以及全株具芳香气味等特征。形态特征分析与系统发育分析均支持该新种成立。模式标本现存于福建农林大学标本馆。  相似文献   

11.
The genus Cayratia Juss. in the traditional sense (i.e., Cayratia s.l.) of the grape family has been shown to be non‐monophyletic. Previous studies supported the splitting of Cayratia s.l. into three genera, that is, Cayratia s.s., Causonis Raf., and a new genus representing the African Cayratia clade. However, the morphology of the African Cayratia clade has not been studied carefully and its phylogenetic position within Vitaceae remains unclear. Our study integrates molecular, distributional, and morphological data and supports the recognition of the new genus Afrocayratia from continental Africa and Madagascar. Phylogenetic analyses strongly support the monophyly of Afrocayratia and resolve it as a sister of Cayratia s.s. based on the chloroplast data, but it is placed sister to Cyphostemma based on the internal transcribed spacer dataset. Molecular dating suggests that Afrocayratia split with Cayratia s.s. during the Paleocene, but that the extant species of Afrocayratia did not diversify until the early Miocene. Afrocayratia differs from its allied genera in having short stigmas and seeds with subcircular ventral infold cavities in cross‐section. Three clades are detected within Afrocayratia, with A. debilis (Baker) J.Wen & L.M.Lu as the first diverged lineage. The second diverged lineage includes A. delicatula (Willems) J.Wen & Z.D.Chen and A. gracilis (Guill. & Perr.) J.Wen & Z.D.Chen. The third diverged lineage includes A. imerinensis (Baker) J.Wen & L.M.Lu, A. longiflora (Desc.) J.Wen & Rabarijaona, and A. triternata (Baker) J.Wen & Rabarijaona from Madagascar, which form a monophyletic group that diverged from the second lineage in the middle Miocene. Combining the morphological and molecular evidence, we formally describe the new genus Afrocayratia, make seven new combinations, and provide a key to species of the genus.  相似文献   

12.
Angelica is a taxonomically complex genus widespread throughout the North Temperate Zone. Previous phylogenetic studies of the genus have focused primarily on its East Asian species. The relationships among its North American members, the monophyly of these species, and the value of fruit morphology in circumscribing its taxa have yet to be examined. This study represents the most comprehensive sampling of Angelica to date (100 species) and includes all 26 species in North America. Relationships are inferred using Bayesian inference, maximum likelihood, and maximum parsimony analyses of ITS sequences and, for multiple accessions of each North American species, cpDNA ndhF-rpl32, rpl32-trnL, and psbM-psbD sequences. The fruit morphological characters examined were those considered phylogenetically important in East Asian Angelica. The results revealed that the North American species fell into three major clades: North American Angelica clade, Archangelica clade, and the Eurasian Angelica clade. Angelica dawsonii has affinities with Lomatium brandegeei. Fourteen species within the North American Angelica clade were strongly supported as monophyletic. Two paraphyletic species resulted in new combinations in A. lineariloba and A. venenosa. Conflict between the ITS-derived and cpDNA-derived phylogenies and the lack of resolution in portions of the trees may be due to chloroplast capture and rapid species radiation. Fruit morphology supported some interspecific relationships based on molecular data, and relationships revealed by ITS and cpDNA data were roughly in accordance with fruit classification type and geographic distribution region, respectively. A diagnostic key based on fruit morphology is provided for the identification of the North American Angelica taxa.  相似文献   

13.
梁思琪  张宪春  卫然 《生物多样性》2019,27(11):1205-159
广泛的杂交和多倍化使得铁角蕨属(Asplenium)下存在着许多分类困难的物种复合体, 针对这些类群进行整合分类学的研究, 有助于我们更加全面和深入地理解物种的界限以及形成机制。线裂铁角蕨复合体(Asplenium coenobiale complex)是铁角蕨属下一个形态多样性较高的类群, 由于缺乏全面取样和系统研究, 该复合体的物种划分长期存在争议。本研究选取线裂铁角蕨复合体中形态变异和地理分布具有代表性的个体, 通过孢粉学研究确定该类群的生殖特性, 运用流式细胞分析获取倍性信息, 同时结合叶绿体和核基因组片段系统发生分析的证据, 对该类群的系统演化关系和起源方式进行了探讨。结果表明: (1)虽然部分孢子囊败育的情况在线裂铁角蕨复合体中十分普遍, 但正常孢子囊内形成的64个孢子说明该类群植物仍能进行正常的有性生殖; (2)该复合体中存在着倍性变异, 其中多角铁角蕨(A. cornutissimum)是二倍体, 而其他成员均为四倍体; (3)依据母系遗传的叶绿体序列所构建的系统发生关系将该类群划为4个分支, 与基于核基因序列构建的系统树存在冲突, 这暗示杂交可能在该复合体的形成过程中起到了重要的推动作用。综上所述, 我们建议将线裂铁角蕨复合体划分为4个物种, 即同源四倍体新种马关铁角蕨(A. maguanense sp. nov.), 二倍体多角铁角蕨, 以及两个由同一对亲本正反交产生的异源四倍体线裂铁角蕨(A. coenobiale)和叶基宽铁角蕨(A. pulcherrimum)。  相似文献   

14.
Phylogenetic studies using DNA sequences of two chloroplast regions, rbcL and trnL-F, demonstrate that the proposed genus Ceterach is a small clade within the large genus Asplenium, and sister to the Phyllitis clade. The Ceterach clade is characterised by irregular anastomosing veins and often densely scaled leaf blades. Its taxonomic status as a group nested within Asplenium is confirmed, and it is accepted here as a subgenus with seven species. The Ceterach clade comprises four lineages that correspond to disjunct polyploid complexes: the A. aureum clade forming a polyploid complex (4×, 6×, 8×) in Macaronesia, the A. ceterach clade forming a polyploid complex (2×, 4×, 6×) in the Mediterranean Basin, the A. paucivenosum clade (4×, 6×) in central Asia, and the A. dalhousiae clade (2×) with a disjunct distribution in the Himalaya, Yemen and Eritrea, and southwestern North America. Asplenium paucivenosum is sister to all other members of the Ceterach clade, whereas A. dalhousiae is sister to the A. aureum clade that includes tetraploid A. aureum, hexaploid A. lolegnamense, and octoploid A. parvifolium. Asplenium ceterach and its variations – including the hexaploid A. ceterach subsp. mediterraneum subsp. nov. first described below – form a monophyletic unit, sister to a clade consisting of A. aureum and A. dalhousiae. Asplenium cordatum from Africa and A. haugthonii from the isolated atlantic island of St. Helena are not members of the Ceterach clade, which suggests that leaf blades with dense indumenta have evolved at least twice within asplenioid ferns. The allotetraploid species A. hybridum has the chloroplast DNA from A. ceterach, and therefore the latter species is the maternal ancestor of the former. The other parent of this hybrid species is A. sagittatum that is nested within the sister clade of Ceterach, the Phyllitis clade comprising A. sagittatum and A. scolopendrium. The findings suggest that the current distribution of Ceterach is either the result of long-distance dispersal or represents fragmented relicts of a previously more widely distributed species.  相似文献   

15.
Phylogeographic and evolutionary studies are necessary to establish solid taxonomic treatments and to implement effective conservation programs. Unfortunately, a well‐argued and well‐founded taxonomic framework is still lacking for some Mediterranean taxa. This is the case of Arenaria section Pseudomoehringia, a group that currently comprises three species endemic to the Iberian Peninsula (A. funiculata, A. suffruticosa, and A. tejedensis) and A. glochidisperma, which is restricted to the Rif mountains, North Africa. However, the taxonomic boundaries and phylogenetic relationships among these species are still uncertain. To explore the evolutionary history and phylogeographic patterns within this section, analyses based on nuclear (amplified fragment length polymorphism and internal transcribed spacer) and plastid DNA markers (psbA‐3’ trnK‐matK and rps16) were performed. Our study has confirmed the monophyly of the section, in which two species are clearly identified (A. funiculata and A. glochidisperma) and an additional species complex (“A. suffruticosa + A. tejedensis complex”) is also supported as a monophyletic clade. The phylogeographic results point toward a dispersal event of a common ancestor of the group from the Iberian Peninsula, giving rise to A. glochidisperma in North Africa. Moreover, A. funiculata and A. glochidisperma are identified as closely related species edaphically differentiated across the Strait of Gibraltar. Our study indicates low levels of a recent gene flow among populations of the “A. suffruticosa + A. tejedensis complex,” which are genetically highly structured and suggest an isolation by distance pattern, probably due to a combination of ecological and geographic barriers. Furthermore, the taxonomic and conservation status of taxa included in Arenaria section Pseudomoehringia has been reviewed.  相似文献   

16.
基于Illumina平台对朱砂根和红凉伞叶绿体全基因组进行测序,利用生物信息学比较叶绿体基因组结构特征与变异程度,旨在明确朱砂根(Ardisia crenata)及红凉伞(Ardisia crenata var. bicolor)叶绿体基因组特征及差异,并与同科其他物种叶绿体全基因组进行比较分析,确定其在紫金牛属系统发育位置。结果表明,朱砂根和红凉伞均为由一个大单拷贝区(LSC)、一个小单拷贝区(SSC)和一对反向重复区(IRa/IRb)构成的环状四分体结构,注释得到132个基因,其重复序列的类型与分布模式相似,但数量有所差异。其中psbAmatKrpoC2ropBndhKaccDndhFndhDndhHycf1等基因的编码区存在差异,这些位点为朱砂根分子鉴定提供新位点。朱砂根及红凉伞叶绿体基因组具有较高保守性,叶绿体基因组之间没有重排或倒置,IR区序列变异最低,SSC区变异程度最高。系统发育树分析表明紫金牛科和报春花科为两个分支,朱砂根和红凉伞归为紫金牛科,且朱砂根与红凉伞亲缘关系最为密切,从分子水平为红凉伞作为朱砂根变种提供了科学解释。本研究解析了朱砂根及变种红凉伞叶绿体基因组结构,探讨了紫金牛科属间系统发育关系,也为紫金牛科药用植物分类鉴定、系统进化及资源开发利用研究奠定基础。  相似文献   

17.
【目的】分析蜜蜂属Apis的系统发育关系,并在此基础上探讨蜜蜂属舞蹈方向、舞蹈声音、营巢环境、巢脾结构的祖先状态和演变过程。【方法】PCR扩增并测定中国分布的蜜蜂属内东方蜜蜂A. cerana、西方蜜蜂A. mellifera、大蜜蜂A. dorsata、黑大蜜蜂A. laboriosa、小蜜蜂A. florea和黑小蜜蜂A. andreniformis的线粒体COⅠ基因序列,并从NCBI数据库中下载分布于其他国家或地区的上述6种蜜蜂以及绿努蜂A. nulunsis、苏拉威西蜂A. nigrocinta、沙巴蜂A. koschevnikovi、炳式大蜜蜂A. dorsata binghami的COⅠ同源序列。分别利用最大简约法(MP)、最大似然法(ML)和贝叶斯分析(BI)依据这些序列数据构建蜜蜂属系统发育关系。对蜜蜂属上述种的舞蹈语言和筑巢行为进行编码并作为性状特征标记到系统发育树中,利用简约法对祖先状态进行追溯。【结果】系统发育分析结果表明,蜜蜂属可划分为3大类群,即穴居蜜蜂类群(东方蜜蜂、西方蜜蜂、苏拉威西蜂、绿努蜂、沙巴蜂)、大蜜蜂类群(大蜜蜂、黑大蜜蜂)和小蜜蜂类群(小蜜蜂、黑小蜜蜂);小蜜蜂类群更加接近于祖型,大蜜蜂类群和穴居蜜蜂类群是两支单系;炳式大蜜蜂是独立于大蜜蜂和黑大蜜蜂的蜂种,且与黑大蜜蜂的亲缘关系更近。祖先状态重建结果显示:蜜蜂属祖先在露天环境下筑造垂直的单脾,且在传播食物或巢址信息时跳水平方向的无声摆尾舞,有嗡嗡声的舞蹈及筑造复脾是后来形成的。【结论】COⅠ基因可作为分子标记用于分析蜜蜂属的舞蹈和筑巢行为的祖先状态及进化过程;蜜蜂筑造复脾、跳有嗡嗡声的舞蹈是后期的适应性进化行为。  相似文献   

18.
鄂尔多斯高原3个水土保持树种的水分利用策略   总被引:2,自引:0,他引:2  
为了解植物对环境的适应对策,通过测定鄂尔多斯高原东部丘陵区3个水土保持树种沙棘、油松和山杏的枝条木质部水和各潜在水源的δ18O值及叶片的δ13C值,应用多元线性混合模型分析各潜在水源的贡献比例,分析3个树种水分来源和水分利用效率的季节动态和种间差异。结果表明: 沙棘、油松和山杏在5月主要利用10 cm深度土壤水,分别占其总水源比例的88.5%、94.0%和91.6%。7月,沙棘主要利用10~25 cm土层土壤水和雨水,比例为44.6%和35.4%;油松主要利用雨水,比例为93.7%;山杏主要利用25~100 cm土层土壤水和雨水,比例分别为55.9%和36.8%。9月,沙棘主要利用25 cm深度和75~100 cm土层土壤水,比例为88.9%;油松主要利用10 cm和50~75 cm土层土壤水,比例为84.5%;山杏利用10~100 cm土层土壤水。5月沙棘的水分利用效率显著高于7月和9月。7月油松的水分利用效率显著高于9月。5月和7月沙棘的水分利用效率显著高于油松和山杏。3个树种在不同季节根据不同水源的可利用性,选择利用不同深度的土壤水或雨水。沙棘和油松干旱时能够提高水分利用效率适应环境变化,可能比山杏更适应当地的半干旱环境。  相似文献   

19.
The two ribosomal DNA internal transcribed spacers (1 and 2) of the hookworms Ancylostoma caninum, A. tubaeforme, A. ceylanicum and A. duodenale were sequenced. The sequence lengths were similar among the four species, except that A. ceylanicum had slightly longer (by 5–7 bp) internal transcribed spacer 1 and 2 sequences. The predicted secondary structure of the internal transcribed spacer 2 precursor rRNA was similar for all species, despite interspecific differences in primary sequence ranging from 0.9% to 13.2%. Interspecific differences in internal transcribed spacer 1 sequence ranged from 0.9% to 7.5%. A cladistic analysis of the sequence data, using the human hookworm Necator americanus as the outgroup, provided little resolution of the phylogenetic relationships, except that A. ceylanicum occurred on a branch external to the other three species. Nonetheless, internal transcribed spacers 1 and 2 may provide useful phylogenetic information at higher taxonomic levels within the superfamily Ancylostomatoidea.  相似文献   

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