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1.
The results of a comparative survey on pollen morphology in theBoragineae by means of light, scanning and transmission electron microscopy are presented and discussed in relation to the taxonomy of the tribe. Multivariate analyses lead to the recognition of 15 pollen morphotypes for which a discriminant key is proposed. The discriminatory characters concern mainly the stereostructural and ultrastructural features of the grains, such as tectum sculpture and aperture morphology, while the number of apertures appears variable within genera and even single species. Seven out of the 12 investigated genera, as currently circumscribed, are matched by palynological data:Anchusella, Borago, Brunnera, Elizaldia, Lithodora, Symphytum andTrachystemon. On account of aperture shape,Lithodora is however closer to theLithospermeae than to theBoragineae. Other genera, and in particularNonea, show a wide variation in tectum ornamentation, shape of grains and number of apertures. Palynological data do not support a broad concept of the genusAnchusa, and point to the autonomy of the satellite generaHormuzakia, Gastrocotyle, Phyllocara, Pentaglottis andCynoglottis.  相似文献   

2.
The nectar–sugar profile (fructose, glucose and sucrose) of 14 species of Anchusa and five members of the allied genera Anchusella, Cynoglottis, Hormuzakia and Lycopsis (Boraginaceae: tribe Boragineae) was determined. Most of the species examined (c. 74%) produce sucrose‐dominant nectar, whereas the remaining taxa produce sucrose‐rich nectars. Little variation in nectar–sugar composition was found in some species, even when sampling was repeated in different years and/or localities. Average sucrose concentration was 57.75% (coefficient of variation 19.1%). The only floral morphological character that was correlated with the nectar–sugar profile is the length of the corolla tube, as taxa with relatively long floral tubes produce nectar with lower glucose concentrations. The flowering period is also related to sugar composition, as nectar of late‐flowering species contains lower sucrose concentrations. However, small differences in sugar profiles do not reflect phylogenetic relationships based on molecular studies. It would appear that dry habitats and time of flowering are the main determinants of nectar–sugar composition in the genus Anchusa sensu lato. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 162 , 616–627.  相似文献   

3.
A comparative study of karyotype morphology and heterochromatin patterns in Brunnera and Cynoglottis (Boraginaceae) was carried out with traditional methods and Giemsa C-banding. Two polymorphic species of Cynoglottis , each with two subspecies, and two of Brunnera were investigated using native population samples from the central-eastern Mediterranean and Middle East. Pollen size of these samples was measured to investigate relationships with ploidy level. C. barrelieri subsp. barrelieri and subsp. serpentinicola are characterized by In = 18 and smaller pollen grains in contrast to C. chetikiana subsp. chetikiana and subsp. paphlagonica , which are fundamentally tetraploid with 2n = 36. The occurrence of cytotypes with 2n –/2 and 2n = 24 in both subspecies of C. chetikiana , however, would suggest x = 6 as the original haploid number and x = 9 as a derived one. Furthermore, the finding of a hypoploid cytotype with 2n = 16 in C. barrelieri ssp. barrelieri was consistent with previous reports and suggested relationships with Anchusa. Karyoevolutionary processes possibly associated with such a wide chromosome variation in Cynoglottis are discussed. Brunnera macrophylla and B. orientalis share a complement of 2n= 12 and an apparently identical karyotype, which differs from Cynoglottis in terms of asymmetry, chromosome size and morphology. A basic C-banding style was present in Brunnera and Cynoglottis , but heterochromatin content increased from the former to the latter. The parallel increase in chromosome number, heterochromatin content and size of the pollen from Brunnera to Cynoglottis may reflect an evolutionary progression, and is consistent with the supposed ancient origin of Brunnera.  相似文献   

4.
A molecular phylogenetic analysis of Cynoglottis was performed to evaluate previous hypotheses based on non-molecular evidence concerning the position of this genus within Boraginaceae tribe Boragineae. ITS-5.8S and trnLUAA sequences from the nuclear and chloroplast non-coding genomes were obtained for four Cynoglottis taxa and selected members of the related genera Anchusa, Anchusella, Gastrocotyle, Brunnera and Pentaglottis. Cynoglottis is monophyletic, but neither trnL nor ITS support a close relationship with Brunnera, unlike previously supposed on morphological grounds. Brunnera is, instead, related to the southwestern European monotypic genus Pentaglottis, with which it forms a basal clade. ITS-5.8S sequences show that Anchusa thessala, a southeastern European annual species of Anchusa subg. Buglossellum, is sister to Cynoglottis and that the two taxa form a clade which also includes the Balkan endemic Gastrocotyle macedonica. Species of Anchusa subg. Anchusa form a separate lineage with high bootstrap support, suggesting that this heterogeneous genus is paraphyletic with respect to Cynoglottis. ITS sequences also discriminate between the Balkan-Apenninic diploid C. barrelieri and the Anatolian tetraploid C. chetikiana, albeit with low support. The molecular results are discussed in the light of karyological, morphological and chorological aspects.This work has been supported by M.I.U.R. 40% 2003 and the University of Firenze.  相似文献   

5.
A selection of Boraginaceae genera was used to obtain a framework for the phylogenetic position of some tribes belong to subfamily Boraginoideae and genera within tribe Eritrichieae (Heterocaryum, Rochelia, Eritrichium, Lappula, Lepechiniella, and Asperugo) and related species. Our results were produced on the basis of nrDNA ITS and cpDNAtrnL-F sequences. The combined nrDNA ITS trnL-F data confirm four main clades of Boraginoideae comprising Echiochileae, Boragineae, Lithospermeae, and Cynoglosseae s. l. (including Eritrichieae, Cynoglosseae s. str., and Myosotideae). The tribe Eritrichieae itself at the current status is paraphyletic; some members, for example Asperugo procumbens, Lepechiniella inconspicua, Myosotidium hortensia, and Cryptantha flavoculata are placed out of the core tribe Eritrichieae. The genus Heterocaryum is monophyletic and allied with a subclade of genera Lappula, Lepechiniella, Eritrichium, and Rochelia. Rochelia is monophyletic, but Eritrichium and Lappula are non-monophyletic. Lepechiniella is nested among a group of Lappula species.  相似文献   

6.
Past classifications of the tribe Acacieae Rchb. are outlined and the confusion concerning the relationships of the three subgenera of Acacia Mill. are highlighted. A plastid DNA analysis of Acacieae shows that the genus Acacia is not monophyletic. Furthermore subgenera Acacia Vassal and Aculeiferum Vassal are sister taxa and neither appear closely related to subgenus Phyllodineae (DC.) Ser. Subgenera Acacia and Aculeiferum form a clade that is basal to a well-supported clade consisting of tribe Ingeae Benth. taxa, Faidherbia albida (Del.) A. Chev. and subgenus Phyllodineae. The series of relationships suggested by the cpDNA data contradicts previous investigations of the tribe. Possible explanations of this conflict are explored, and the taxonomic implications of the plastid DNA data set are considered.  相似文献   

7.
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.  相似文献   

8.
Worldwide in distribution, the tribe Muscini comprises 21 accepted genera and about 350 species. In the present study, a cladistic analysis based upon adult morphological characters is carried out in order to discuss the monophyly of the tribe and its genera, the intergeneric relationships and, in some cases, also the intrageneric relationships. As a result, Muscini is supported as a monophyletic tribe sister-group of Stomoxyini. Except for Morellia Robineau-Desvoidy, Curranosia Paterson, and Eudasyphora Townsend, all the remaining genera are monophyletic. The results are dubious for Polietes Rondani, which was then provisionally kept unchanged. Morellia was broadened to include the Neotropical endemic genera Parapyrellia Townsend, Trichomorellia Stein, and Xenomorellia Malloch. Therefore, a new classification is proposed for Morellia in which it is divided into four subgenera: Morellia s.s. , Parapyrellia , Trichomorellia , and Xenomorellia . Furthermore, the previously proposed subgenus Dasysterna Zimin is given new status as a genus; however, as it is preoccupied by Dasysterna Dejean, the new replacement name Ziminellia nom. nov. is proposed herewith. Eudasyphora was found to be a paraphyletic group relative to Dasyphora Robineau-Desvoidy; both genera are hence synonymized, and Dasyphora is classified in three subgenera: Dasyphora s.s. , Eudasyphora , and Rypellia Malloch. The analysis demonstrated that the traditional classification of Musca Linnaeus into subgenera is artificial and, moreover, that the use of characters from male genitalia could be strongly informative for classifying the genus in phylogeny-supported species groups. Finally, the new classification proposal for Muscini recognizes 18 genera and, furthermore, two undescribed genus-ranked taxa are indicated.  © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 149 , 493–532.  相似文献   

9.
Comprehensive taxonomic sampling can vastly improve the accuracy of phylogenetic reconstruction. Here, we present the most inclusive phylogenetic analysis of Arvicolinae (Mammalia, Rodentia) to date, combining all published cytochrome  b gene sequences of greater than 1097 bp and new sequences from two monotypic genera. Overall, the phylogenetic relationships between 69 species of voles and lemmings, representing 18 genera and 10 tribes, were studied. By applying powerful modern approaches to phylogenetic reconstruction, such as maximum likelihood and Bayesian analysis, we provide new information on the early pulse of evolution within the Arvicolinae. While the position of two highly divergent lineages, Phenacomys and Ondatra , could not be resolved, the tribe Lemmini, appeared as the most basal group of voles. The collared lemmings (Dicrostonychini) grouped together with all of the remaining tribes. The two previously unstudied monotypic genera Dinaromys and Prometheomys form a moderately well-supported monophyletic clade, possibly a sister group to Ellobius (Ellobiusini). Furthermore, with one exception, all tribes ( sensu Musser & Carleton, 2005) proved to be monophyletic and can thus be regarded as meaningful evolutionary entities. Only the tribe Arvicolini emerged as paraphyletic in both analyses because of the unresolved phylogenetic position of Arvicola terrestris . Steppe voles of the genus Lagurus were solidly supported as a sister group to the Microtus and allies clade.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 94 , 825–835.  相似文献   

10.
Sequences of the ITS1–5.8S–ITS2 region of nuclear ribosomal DNA were generated for 12 species from 9 genera of Lejeuneaceae and a single species of Jubulaceae (outgroup). The taxon sampling of Lejeuneaceae included representatives of the two widely recognized subfamilies, Lejeuneoideae and Ptychanthoideae. The molecular dataset was analysed independently and in combination with a morphological dataset. The nrITS dataset and the combined dataset resulted in identical topologies. The genus Bryopteris, sometimes treated as a separate family Bryopteridaceae, is nested within the Lejeuneaceae subfamily Ptychanthoideae. Lejeuneaceae subfamily Lejeuneoideae proved to be paraphyletic with the tribe Lejeuneeae sister to Ptychanthoideae, albeit without significant bootstrap support. The tribes Brachiolejeuneeae and Cheilolejeuneeae of Lejeuneoideae, established recently based on morphological evidence, are well supported in bootstrap analyses both of the ITS and the combined molecular–morphological datasets. The results support classifications of Lejeuneaceae based on morphological data and demonstrate the usefulness of the ITS region for phylogenetic studies within or among closely related genera of Lejeuneaceae.  相似文献   

11.
Mitochondrial DNA sequences were used to reconstruct the phylogeny of the Penaeus s.l. genus of marine shrimp. This phylogeny was used to test the validity of hypotheses on the species groupings, in particular the subgenus/genus subdivision, and on the species' evolutionary history. Newly derived sequences of both 16S rRNA and COI genes from 19 species of Penaeus s.l. and one outgroup were combined with previous sequences from seven additional species to allow analysis of 26 of the 28 recognised (or nominated) species. Phylogenetic analyses do not support the validity of all the previously created six subgenera (or genera) but provide evidence for division of the genus into two previously unrecognised clades (Melicertus+Marsupenaeus and Penaeus s.s.+Fenneropenaeus+Farfantepenaeus+Litopenaeus). A key conclusion from a previous molecular study, that the subgenera Farfantepenaeus and Litopenaeus are paraphyletic, was rejected. The molecular data support an Indo-West Pacific origin of the genus, with a single relatively recent colonisation of the Western Hemisphere, and subsequent subdivision into two clades prior to the emergence of the Panamanian isthmus.  相似文献   

12.
Phylogenetic relationships among members of the Aphid genus Brachycaudus (Homoptera: Aphididae) were inferred from partial sequences of mitochondrial cytochrome B oxidase (CytB), two partial fragments of mitochondrial cytochrome C oxidase subunit I (COI) and the internal transcribed spacer II (ITS2) of ribosomal DNA. Twenty-nine species, with several specimens per species, were included, representing all the historically recognized species-groups and subgenera used in the genus except the monospecific subgenus Mordvilkomemor. Results indicate that the genus Brachycaudus is a well-supported monophyletic group. While our results validate the monophyly of subgenera Thuleaphis , Appelia and Brachycaudus s. str. , they reveal two discrepancies in the classical taxonomy. First, the monotypic subgenus Nevskyaphis does not appear valid. Second, the traditionally defined Acaudus subgenus is not monophyletic. On the other hand, our phylogenetic trees corroborate Andreev's recent definition of Acaudus and Brachycaudina. However, they clearly show that the subgenera Prunaphis , Nevskyaphis and Scrophulaphis as defined by this author do not form monophyletic groups. Our results also highlight a highly supported clade that has not been discussed by previous authors; this clade could form a new subgenus, the subgenus Nevskyaphis . Finally, our study shows that molecular data and morphology meet the same limits in delimiting species groups and species themselves. Species groups in which taxonomic treatment is difficult are polytomous. Furthermore, except for one node clustering Brachycaudus s. str . and Appelia, intersubgeneric relationships remain poorly resolved even when several genes are added to the phylogenetic analysis. These results, together with previous studies in other aphid groups suggest that diversification might have been a rapid process in aphids.  相似文献   

13.
14.
根据ITS序列证据重建防己科蝙蝠葛族的系统发育   总被引:10,自引:4,他引:6  
研究了国产防己科蝙蝠葛族tirb.Menispermeae9属20种和外类群青牛胆族trib.Tinosporeae 2属3种植物完整的ITS(包括5.8S rDNA)序列。trib.Menispermeae的ITS长527~601 bp,排序后长667bp。当gap处理为missing时具281个有信息位点。PAUP软件分析结果表明:①trib.Menispermeae是一个单系类群,该分支得到hootstrap l00%的支持;②确定了存疑种Pachygone valida的系统学位置,该种是Coc—culus属的成员;③Sinomenium和Menispermum两属有很近的系统学关系,组成族内稳定的一支,它们的ITS序列同源性极高,ITS1比族内其它属长41~73bp;④Stephania和Cyclea也是系统发育关系很近的两个类群。前者具两个主要分支,其IIS1、ITS2的G+C含量差异较大,在种类组成上,该两大支与传统上Stephania属内处理的2个亚属——千金藤亚属subgen.Stephania和山乌龟亚属subgen.Tuberiphania基本一致;Cyclea属内种间的ITS序列差异小,同源性极高。  相似文献   

15.
Abstract: Sequences of the internal transcribed spacers (ITS1 and ITS2) of nuclear ribosomal DNA were analysed for 44 Artemisia species (46 populations) representing all the five classical subgenera and the geographical range of the genus, 11 species from 10 genera closely related to Artemisia, and six outgroup species from five other genera of the Anthemideae. The results definitely support the monophyly of the genus Artemisia in its broadest sense (including some taxa segregated as independent genera, like Oligosporus and Seriphidium ). Eight main clades are established in this molecular phylogeny within Artemisia; they agree in part with the classical subdivision of the genus, but they also suggest that some infrageneric groups must be redefined, especially the subgenus Artemisia. The subgenera Tridentatae and Seriphidium are independent from each other. Some of the satellite genera are clearly placed within Artemisia ( Artemisiastrum, Filifolium, Mausolea, Picrothamnus, Sphaeromeria, Turaniphytum ), whereas some others fall outside the large clade formed by this genus (Brachanthemum, Elachanthemum, Hippolytia, Kaschgaria). Our results, correlated to other data such as pollen morphology, allow us to conclude that the subtribe Artemisiinae as currently defined is a very heterogeneous group. Affinities of the largest genus of the subtribe and tribe, Artemisia, and of other genera of the subtribe to some genera from other subtribes of the Anthemideae strongly suggest that subtribe Artemisiinae needs a deep revision and redefinition. Phylogenetic utility of region trnL-F of the plastid DNA in the genus Artemisia and allies was also evaluated: sequences of the trnL-F region in Artemisia do not provide phylogenetic information.  相似文献   

16.
The phylogeny of the tribe Menispermeae (Menispermaceae) represented by 20 species of 9 genera in China, was reconstructed based on sequence analysis of the internal transcribed spacers (ITS) (including ITS1, ITS2, and 5.8S rRNA gene ) of nuclear ribosomal DNA. Three species of two genera in the tribe Tinosporeae were designated as outgroups. Direct PCR sequencing method was used in the study, The sizes of ITS within trib. Menispermeae range from 527 to 601 bp. The aligned length is 667 bp, which provides 281 phylogenetically informative sites when gaps are treated as missing. The results of phylogenetic analyses show that: ① trib. Menispermeae is a monophyletic group strongly supported by a bootstrap value of 100%; ② Pachygone valida, whose systematic position was uncertain in the previous classification, should be placed in the Cocculus. ③Sinomenium and Menispermum are two close genera of the tribe. Their sequcences are very similar to each other, with ITS1 having 41 to 73 bp longer than that of the other genera in trib. Menispermeae. ④ Stephania and Cyclea are also closely related. The former forms two major clades, which are approximately consistent with the two traditional subgenera: subgen. Stephania and subgen. Tuberiphania. The species of Cyclea are mutually little diverged in complete ITS sequences, and they com-prise a sister clade to the genus Stephania.  相似文献   

17.
A molecular phylogenetic study of Plantago L. (Plantaginaceae) analysed nucleotide variation in the internal transcribed spacers (ITS) of nuclear ribosomal and plastid trnL-F regions. Included are 57 Plantago species, with two Aragoa species as the ingroup and three Veronica species as the outgroup. Phylogenetic analysis using maximum parsimony identified five major clades, corresponding to the taxonomic groups Plantago subgenera Plantago, Coronopus, Psyllium, Littorella and Bougueria . Aragoa is sister to genus Plantago . Plantago subgenus Littorella is sister to the other subgenera of Plantago . The results are in general correlated with a morphological phylogenetic study and iridoid glucoside patterns, but Plantago subgenus Albicans is paraphyletic and should be included in Plantago subgenus Psyllium sensu lato to obtain a monophyletic clade with six sections. Plantago section Hymenopsyllium is more closely related to section Gnaphaloides than to section Albicans . Plantago subgenus Bougueria is sister to subgenus Psyllium s.l. section Coronopus in Plantago subgenus Coronopus is subdivided in two series. Only some of the sections can be resolved into series. DNA variation within genus Plantago is high, a result that would not have been predicted on the basis of morphology, which is relatively stereotyped. If we calibrate a molecular clock based on the divergence of P. stauntoni , endemic to New Amsterdam in the southern Indian Ocean, we calculate the time of the split between Plantago and Aragoa to be 7.1 million years ago, which is congruent with the fossil record.  © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 139 , 323–338.  相似文献   

18.
19.
The plastid matK gene, trnL/F spacer, and nuclear rDNA ITS were sequenced for 36 species of Leontodon and 29 taxa of related genera of tribe Lactuceae. Phylogenetic relationships inferred from the independent and combined data are largely congruent and reveal that Leontodon sensu lato (s.l.) as presently defined is diphyletic: L. subgenus Leontodon forms a clade with Helminthotheca, Picris and Hypochaeris as sister genera, whereas L. subgenus Oporinia appears as a separate clade with strong bootstrap support and is thus better treated as a separate genus. Previous sectional classifications of Leontodon s.l. are considered in the light of DNA and additional morphological and karyological data. Support is presented for a core group of Hypochaeridinae sensu stricto (s.s.) with the two clades of Leontodon s.l., Helminthotheca, Picris, and Hypochaeris, whereas Urospermum, Hyoseris, Aposeris, and Rhagadiolus appear to be positioned more distantly.  相似文献   

20.
Historically, Pappophoreae included the genera Cottea, Enneapogon, Kaokochloa, Pappophorum and Schmidtia. Some authors consider this tribe as a well-supported monophyletic group; while other evidences reveals Pappophoreae as polyphyletic, with Pappophorum separated from the rest of the tribe. When the latter happens, it can form a clade with Tridens flavus. Molecular phylogenetic analyses of the subfamily Chloridoideae have included few species of Pappophoreae; therefore, further research involving more representatives of this tribe is needed. With the aim of providing new evidence to help clarify the phylogenetic position of Pappophorum and its relationships with other genera of the tribe and the subfamily Chloridoideae, eight new sequences of ITS and trnL-F regions of Pappophoreae species were generated. These sequences were analyzed together with other available sequence data obtained from GenBank, using maximum parsimony and Bayesian inference, for individual (trnL-F or ITS) or combined trnL-F/ITS data sets. All analyses reveal that Pappophoreae is polyphyletic, with Pappophorum separated from the rest of the tribe forming a well-supported clade sister to Tridens flavus.  相似文献   

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