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The Sino-Himalayan Mountain Region is a major center of diversity of Heracleum (Apiaceae, Tordylieae, Tordyliinae), yet the phylogenetic relationships among its rich diversity of endemic taxa are largely unknown. In this study, we (1) investigate the monophyly of Heracleum and ascertain the phylogenetic placements of those species of Heracleum from China that fall outside of the group; (2) estimate phylogenetic relationships within Heracleum sensu stricto, particularly among those species occurring in the Hengduan Mountain Region of southwestern China; and (3) reconstruct the biogeographic history of Heracleum sensu stricto. To achieve these objectives, Bayesian inference and maximum-parsimony analyses of the nuclear ribosomal DNA (nrDNA) internal transcribed spacer (ITS) region and five noncoding chloroplast DNA (cpDNA) loci (rps16-trnK, rps16 intron, trnQ-rps16, rpl32-trnL, and psbA-trnH), separately and in combination, were carried out. Fruit morphology of the Chinese Heracleum species was examined. Statistical dispersal-vicariance analysis (S-DIVA) was used to reconstruct the biogeographic history. In total, 114 accessions were considered, which included 88 species representing eight genera of subtribe Tordyliinae, 28 of the 29 species of Heracleum occurring in China, and 4 species of Angelica as outgroups. The genus Heracleum is monophyletic upon the exclusion of nine species of Heracleum from China and the inclusion of the Caucasian monotypic genera Mandenovia and Symphyoloma. These nine excluded species show affinities to Tetrataenium, Semenovia, and Angelica. The species of Heracleum endemic to southwestern China form a moderately to strongly supported clade; however, major discordance between the ITS- and cpDNA-derived phylogenies, lack of resolution in the trees, and polyphyly of several species preclude unequivocal hypotheses of phylogenetic relationship. The distinctly clavate vittae, shorter than the length of the mericarp, is a diagnostic feature for Heracleum sensu stricto. Heracleum originated in the West Palearctic, with three possible migration routes leading to its present-day distribution. Major topological conflicts between the ITS and cpDNA trees may be due to interspecific hybridization and/or incomplete lineage sorting. The taxonomic limits of many Chinese Heracleum species remain unclear, possibly because of recent radiation in the Hengduan Mountains.  相似文献   

3.
The genus Blumea (Asteroideae, Asteraceae) comprises about 100 species, including herbs, shrubs, and small trees. Previous studies have been unable to resolve taxonomic issues and the phylogeny of the genus Blumea due to the low polymorphism of molecular markers. Therefore, suitable polymorphic regions need to be identified. Here, we de novo assembled plastomes of the three Blumea species Boxyodonta, B. tenella, and B. balsamifera and compared them with 26 other species of Asteroideae after correction of annotations. These species have quadripartite plastomes with similar gene content, genome organization, and inverted repeat contraction and expansion comprising 113 genes, including 80 protein‐coding, 29 transfer RNA, and 4 ribosomal RNA genes. The comparative analysis of codon usage, amino acid frequency, microsatellite repeats, oligonucleotide repeats, and transition and transversion substitutions has revealed high resemblance among the newly assembled species of Blumea. We identified 10 highly polymorphic regions with nucleotide diversity above 0.02, including rps16‐trnQ, ycf1, ndhF‐rpl32, petN‐psbM, and rpl32‐trnL, and they may be suitable for the development of robust, authentic, and cost‐effective markers for barcoding and inference of the phylogeny of the genus Blumea. Among these highly polymorphic regions, five regions also co‐occurred with oligonucleotide repeats and support use of repeats as a proxy for the identification of polymorphic loci. The phylogenetic analysis revealed a close relationship between Blumea and Pluchea within the tribe Inuleae. At tribe level, our phylogeny supports a sister relationship between Astereae and Anthemideae rooted as Gnaphalieae, Calenduleae, and Senecioneae. These results are contradictory to recent studies which reported a sister relationship between “Senecioneae and Anthemideae” and “Astereae and Gnaphalieae” or a sister relationship between Astereae and Gnaphalieae rooted as Calenduleae, Anthemideae, and then Senecioneae using nuclear genome sequences. The conflicting phylogenetic signals observed at the tribal level between plastidt and nuclear genome data require further investigation.  相似文献   

4.
Apathya is a lacertid genus occurring mainly in south-east Turkey and its adjacent regions (part of Iran and Iraq). So far two morphological species have been attributed to the genus; A. cappadocica (with five subspecies, A. c. cappadocica, A. c. muhtari, A. c. schmidtlerorum, A. c. urmiana and A. c. wolteri) and A. yassujica. The first species occupies most of the genus’ distribution range, while A. yassujica is endemic of the Zagros Mountains. Here, we explored Apathya’s taxonomy and investigated the evolutionary history of the species by employing phylogenetic and phylogeographic approaches and using both mitochondrial (mtDNA) and nuclear markers. The phylogenetic relationships and the genetic distances retrieved, revealed that Apathya is a highly variable genus, which parallels its high morphological variation. Such levels of morphological and genetic differentiation often exceed those between species of other Lacertini genera that are already treated as full species, suggesting the necessity for a taxonomic revision of Apathya. The phylogeographical scenario emerging from the genetic data suggests that the present distribution of the genus was determined by a combination of dispersal and vicariance events between Anatolia and Southwest Asia dating back to the Miocene and continuing up to the Pleistocene. Key geological events for the understanding of the phylogeography of the genus are the movement of the Arabian plate that led to the configuration of Middle East (orogenesis of the mountain ranges of Turkey and Iran) and the formation of Anatolian Diagonal.  相似文献   

5.
The genus Tenacibaculum, a member of the family Flavobacteriaceae, is an abundant component of marine bacterial ecosystems that also hosts several fish pathogens, some of which are of serious concern for marine aquaculture. Here, we applied multilocus sequence analysis (MLSA) to 114 representatives of most known species in the genus and of the worldwide diversity of the major fish pathogen Tenacibaculum maritimum. Recombination hampers precise phylogenetic reconstruction, but the data indicate intertwined environmental and pathogenic lineages, which suggests that pathogenicity evolved independently in several species. At lower phylogenetic levels recombination is also important, and the species T. maritimum constitutes a cohesive group of isolates. Importantly, the data reveal no trace of long-distance dissemination that could be linked to international fish movements. Instead, the high number of distinct genotypes suggests an endemic distribution of strains. The MLSA scheme and the data described in this study will help in monitoring Tenacibaculum infections in marine aquaculture; we show, for instance, that isolates from tenacibaculosis outbreaks in Norwegian salmon farms are related to T. dicentrarchi, a recently described species.  相似文献   

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This paper presents the first molecular phylogeny of the genus Hemsleya using nuclear ITS and plastid trnH-psbA, rpl16, and trnL DNA sequences to examine the relationships among Hemsleya species. Phylogenetic relationships were elucidated using a combined analysis of all four datasets, however, the number of parsimony-informative characters was still insufficient to resolve all relationships. Parsimony and Bayesian trees were highly congruent. Twenty-three species of Hemsleya split into two major clades corresponding to two subgenera, i.e., subg. Graciliflorae and subg. Hemsleya. These results are partly in agreement with Li’s sectional classification. However, the molecular data are inconsistent with Li’s classification at the subsectional level. The molecular phylogeny revealed a striking overall correlation between the phylogenetic relationships of the species and their geographical distribution. The Kangdian ancient landmass could be the center of origin of the genus.  相似文献   

8.
Inferring the evolutionary and biogeographic history of taxa occurring in a particular region is one way to determine the processes by which the biodiversity of that region originated. Tree boas of the genus Corallus are an ancient clade and occur throughout Central and South America and the Lesser Antilles, making it an excellent group for investigating Neotropical biogeography. Using sequenced portions of two mitochondrial and three nuclear loci for individuals of all recognized species of Corallus, we infer phylogenetic relationships, present the first molecular analysis of the phylogenetic placement of the enigmatic C. cropanii, develop a time-calibrated phylogeny, and explore the biogeographic history of the genus. We found that Corallus diversified within mainland South America, via over-water dispersals to the Lesser Antilles and Central America, and via the traditionally recognized Panamanian land bridge. Divergence time estimates reject the South American Caribbean-Track as a general biogeographic model for Corallus and implicate a role for events during the Oligocene and Miocene in diversification such as marine incursions and the uplift of the Andes. Our findings also suggest that recognition of the island endemic species, C. grenadensis and C. cookii, is questionable as they are nested within the widely distributed species, C. hortulanus. Our results highlight the importance of using widespread taxa when forming and testing biogeographic hypotheses in complex regions and further illustrate the difficulty of forming broadly applicable hypotheses regarding patterns of diversification in the Neotropical region.  相似文献   

9.
The process of ecological speciation drives the evolution of locally adapted and reproductively isolated populations in response to divergent natural selection. In Southern Mexico, several lineages of the freshwater fish species of the genus Poecilia have independently colonized toxic, hydrogen sulfide-rich springs. Even though ecological speciation processes are increasingly well understood in this system, aligning the taxonomy of these fish with evolutionary processes has lagged behind. While some sulfide spring populations are classified as ecotypes of Poecilia mexicana, others, like P. sulphuraria, have been described as highly endemic species. Our study particularly focused on elucidating the taxonomy of the long described sulfide spring endemic, Poecilia thermalis Steindachner 1863, and investigates if similar evolutionary patterns of phenotypic trait divergence and reproductive isolation are present as observed in other sulfidic species of Poecilia. We applied a geometric morphometric approach to assess body shape similarity to other sulfidic and non-sulfidic fish of the genus Poecilia. We also conducted phylogenetic and population genetic analyses to establish the phylogenetic relationships of P. thermalis and used a population genetic approach to determine levels of gene flow among Poecilia from sulfidic and non-sulfidic sites. Our results indicate that P. thermalis'' body shape has evolved in convergence with other sulfide spring populations in the genus. Phylogenetic analyses placed P. thermalis as most closely related to one population of P. sulphuraria, and population genetic analyses demonstrated that P. thermalis is genetically isolated from both P. mexicana ecotypes and P. sulphuraria. Based on these findings, we make taxonomic recommendations for P. thermalis. Overall, our study verifies the role of hydrogen sulfide as a main factor shaping convergent, phenotypic evolution and the emergence of reproductive isolation between Poecilia populations residing in adjacent sulfidic and non-sulfidic environments.  相似文献   

10.
A new notosuchian crocodyliform from the Late Cretaceous Bauru Group found in the southeastern State of São Paulo (Brazil) is described here. The new taxon, Caipirasuchus stenognathus, is referred as a new species of the recently erected genus Caipirasuchus within the clade Sphagesauridae based on a phylogenetic analysis of basal mesoeucrocodylians. Caipirasuchus stenognathus is represented by an almost complete skull and lower jaw that has autapomorphic characters that distinguish it from other species of Sphagesauridae. These autapomorphies include: maxilla forming part of the orbital margin (absence of lacrimal-jugal contact), nasal with smooth depressions on the posterior region close to the contact with the maxilla and lacrimal, postorbital with posterior palpebral facet that extends posteriorly underneath the ear-flap groove, and a distinct anterior process of the medial flange of the retroarticular process. Additionally, the new taxon lacks autapomorphic features described in other sphagesaurids. The phylogenetic analysis results in a monophyletic genus Caipirasuchus, that is the sister group of a clade fomed by Sphagesaurus huenei, Caryonosuchus pricei, and Armadillosuchus arrudai. Sphagesaurids also include a basal clade formed by Adamantinasuchus navae and Yacarerani boliviensis. Other notosuchian taxa, such as Mariliasuchus amarali, Labidiosuchus amicum, Notosuchus terrestris, and Morrinhosuchus luziae are successive sister taxa of Sphagesauridae, forming a clade of advanced notosuchians that are restricted to the Late Cretaceous of South America. These results contrast with most previous phylogenetic hypotheses of the group that depicted some members of Sphagesauridae as more closely related to baurusuchids, or found Asian (e.g., Chimaerasuchus) or African (Malawisuchus, Pakasuchus) forms nested within advanced notosuchians that are, according to our analysis, endemic of the Late Cretaceous of South America.  相似文献   

11.
A review of available Caribbean Island red-lists species (CR and EN categories based on the IUCN guidelines from 2001, and E category established according to the IUCN guidelines from 1980) is presented. A database of over 1,300 endemic species that are either Critically Endangered or Endangered sensu IUCN was created. There are molecular systematic studies available for 112 of them. Six of these species (in six genera) are the only members of early divergent lineages that are sister to groups composed of a large number of clades. Seven of the species (in seven genera) belong to clades that have a small number of taxa but are sister to species/genus-rich clades. Ten of the species (in six genera) are sister to taxa restricted to South America or nested in clades endemic to this region. Fifty-seven of the species (in 35 genera) are sister to Caribbean Island endemic species. Erigeron belliastroides, an Endangered (EN) Cuban endemic, is sister to the Galapagos genus Darwiniothamnus. The phylogenetic placement of four of the threatened species resulted in changes in their taxonomic placement; they belong to polyphyletic or paraphyletic genera.  相似文献   

12.
Proterochampsids are crocodile-like, probably semi-aquatic, quadrupedal archosauriforms characterized by an elongated and dorsoventrally low skull. The group is endemic from the Middle-Late Triassic of South America. The most recently erected proterochampsid species is “Chanaresuchus ischigualastensis”, based on a single, fairly complete skeleton from the early Late Triassic Ischigualasto Formation of northwestern Argentina. We describe here in detail the non-braincase cranial and postcranial anatomy of this species and revisit its taxonomy and phylogenetic relationships. The phylogenetic analysis recovered ‘Chanaresuchus ischigualastensis’ as part of a trichotomy together with Gualosuchus reigi and Chanaresuchus bonapartei. Accordingly, “Chanaresuchus ischigualastensis” can be potentially more closely related to Gualosuchus reigi, or even Rhadinosuchus gracilis, than to Chanaresuchus bonapartei. In addition, after discussing previously claimed synapomorphies of Chanaresuchus, we could not find unambiguous support for the monophyly of the genus. As a result, we propose here the erection of the new genus Pseudochampsa for ‘Chanaresuchus ischigualastensis’, which results in the new combination Pseudochampsa ischigualastensis. The information provided here about the anatomy and taxonomy of Pseudochampsa ischiguaslastensis will be useful for future quantitative analyses focused on the biogeography and macroevolutionary history of proterochampsids.  相似文献   

13.
Interspecific hybridization is widespread among plants. Understanding the phylogenetic relationships among species is necessary for revealing the potential hybridization events. Actinidia, best known as kiwifruit genus found throughout a wide range in eastern Asian from Indonesia to Siberia. In this study, phylogenetic relationships of Actinidia species with sympatric distributions were investigated using three chloroplast introns (trnL-F, atpB-rbcL and rpl32-trnL) and three Exon primed intron-crossing (EPIC) markers. Chloroplast phylogeny supports non-monophyly of the five species studied excluding Actinidia fulvicoma var. lanata. The non-monophyly was also revealed by EPIC markers. Our results showed EPIC markers are more variable and informative for phylogenetic inference than that of chloroplast markers. The incongruences between loci from the plastid and nuclear DNA phylogenic trees may stem from incomplete lineage sorting or historical introgression hybridization. Incomplete lineage sorting may explain the non-monophyly between Actinidia chrysantha (section Maculatae) and other four species (section Stellatae), and introgression hybridization and high level of interspecific gene flow may explain the non-monophyly among the species of sect. Stellatae. Thus, natural hybridization and introgression may be common in Actinidia with sympatric distribution.  相似文献   

14.
The genus Fritillaria embraces up to 165 taxa in the family Liliaceae, most of which are of high medicinal and ornamental value and importance. In this study, 44 specimens of the genus representing 9 species were collected from their natural habitats located in 10 provinces of Iran. Phylogenetic analysis was performed based on DNA sequences of the internal transcribed spacer (ITS) of the nuclear ribosomal cistron and the trnL-trnF regions. The phylogeny was constructed using the neighbor joining inference method. Results indicate that the examined samples were evidently diverged into 2 distinct clades. Members of the subgenera Fritillaria and Rhinopetalum formed one clade while the other clade contained the subgenera Theresia and Petilium. There can be seen a high degree of similarity between the only yellow-colored crown imperial specimen and the red-colored specimens. The endemic species of Fritillaria straussii, Fritillaria zagrica and Fritillaria kotschyana which their status within the subgenera known in the genus Fritillaria has been remained undefined, fell into the subgenus Fritillaria. The clades also had relatively reasonable distribution patterns based on the genetic structure, geographical conditions and climate specifications. This study revealed the feasibility of the ITS and trnL-trnF DNA sequence for phylogeny of the genus Fritillaria. This is the first phylogenetic analysis of Fritillaria spp. in Iran.  相似文献   

15.
The types of the species of the Coniacian ammonite genus Hemitissotia Peron, 1897, identified in the Iberian Peninsula (Spain and Portugal), which are currently held in the Wiedmann (Universität Tübingen, Germany) and Choffat (Instituto Geológico e Mineiro, Portugal) collections, have been revised and refigured. New specimens of the taxa Hemitissotia ceadouroensis Choffat, 1898, Hemitissotia celtiberica Wiedmann, 1975b, Hemitissotia turzoi Karrenberg, 1935, Hemitissotia dullai (Karrenberg 1935) and Hemitissotia lenticeratiformis Wiedmann in Wiedmann and Kauffman, 1978 have also been presented. As results, H. celtiberica has been considered as a junior synonym of H. ceadouroensis, and the lectotype of this species and the neotypes of H. turzoi and H. dullai have been designated and figured. Additionally, the geographical and stratigraphical distributions of all of these species have been determined with precision, and several phylogenetic relationships between them have been identified, revealing morphologies that become progressively smaller and more depressed and ornamented (hydrodynamically less efficient), interpreted as an adaptative response to sea-level changes.  相似文献   

16.
Horismenus parasitoids are an abundant and understudied group of eulophid wasps found mainly in the New World. Recent surveys based on morphological analyses in Costa Rica have quadrupled the number of named taxa, with more than 400 species described so far. This recent revision suggests that there is still a vast number of unknown species to be identified. As Horismenus wasps have been widely described as parasitoids of insect pests associated with crop plants, it is of high importance to properly establish the extant diversity of the genus, in order to provide biological control practitioners with an exhaustive catalog of putative control agents. In this study, we first collected Horismenus wasps from wild Phaseolus bean seeds in Central Mexico and Arizona to assess the genetic relatedness of three morphologically distinct species with overlapping host and geographical ranges. Sequence data from two nuclear and two mitochondrial gene regions uncovered three cryptic species within each of the three focal species (i.e., H. missouriensis, H. depressus and H. butcheri). The monophyly of each cryptic group is statistically supported (except in two of them represented by one single tip in which monophyly cannot be tested). The phylogenetic reconstruction is discussed with respect to differences between gene regions as well as likely reasons for the differences in variability between species.  相似文献   

17.
Identification and characterization of near-neighbor species are critical to the development of robust molecular diagnostic tools for biothreat agents. One such agent, Burkholderia pseudomallei, a soil bacterium and the causative agent of melioidosis, is lacking in this area because of its genomic diversity and widespread geographic distribution. The Burkholderia genus contains over 60 species and occupies a large range of environments including soil, plants, rhizospheres, water, animals and humans. The identification of novel species in new locations necessitates the need to identify the true global distribution of Burkholderia species, especially the members that are closely related to B. pseudomallei. In our current study, we used the Burkholderia-specific recA sequencing assay to analyze environmental samples from the Darwin region in the Northern Territory of Australia where melioidosis is endemic. Burkholderia recA PCR negative samples were further characterized using 16s rRNA sequencing for species identification. Phylogenetic analysis demonstrated that over 70% of the bacterial isolates were identified as B. ubonensis indicating that this species is common in the soil where B. pseudomallei is endemic. Bayesian phylogenetic analysis reveals many novel branches within the B. cepacia complex, one novel B. oklahomensis-like species, and one novel branch containing one isolate that is distinct from all other samples on the phylogenetic tree. During the analysis with recA sequencing, we discovered 2 single nucleotide polymorphisms in the reverse priming region of B. oklahomensis. A degenerate primer was developed and is proposed for future use. We conclude that the recA sequencing technique is an effective tool to classify Burkholderia and identify soil organisms in a melioidosis endemic area.  相似文献   

18.
Trichoderma eijii and T. pseudolacteum, are described here as new species from Japan. These species were isolated from decaying wood in the Tomakomai Experimental Forest in Hokkaido Prefecture and from bedlogs on shiitake mushroom (Lentinula edodes) farms, respectively. The species were characterized using a combined approach that included cultural studies, holomorph morphology, and phylogenetic analyses of internal transcribed spacer and protein coding gene sequences (RNA polymerase subunit II, translation elongation factor 1-α, endochitinase, and actin). The results of phylogenetic analyses of these gene sequences indicate that T. eijii belongs to the Hamatum clade and is closely related to Hypocrea pezizoides, H. flaviconidia, and H. atroviridis/T. atroviride, from which it differs mainly in part-ascospore size and anamorphic characteristics. Trichoderma pseudolacteum, which was previously recognized as H. lactea sensu Doi, is morphologically distinct from H. lactea (= Hypocrea citrina) and is strongly supported as a separate lineage based on our phylogenetic analyses.  相似文献   

19.
Triadica (Euphorbiaceae) is a small genus endemic to East Asia and Southeast Asia, consisting of three species differentially adapted to heterogeneous habitats. To date, the phylogenetic relationships of this genus have not been resolved, and there has been no evidence for interspecific hybridization in Triadica. In this study, we sequenced the nrITS regions, two nuclear genes and a chloroplast gene to reconstruct the molecular phylogeny of Triadica and to test the hypothesis of natural hybridization between Triadica sebifera and Triadica cochinchinensis, and between T. sebifera and Tridica rotundifolia. Phylogenetic analysis showed that T. sebifera diverged first within this genus, and T. cochinchinensis and T. rotundifolia were sister species. Both of the two putative hybrids show chromatogram additivity at each of the two nuclear genes, providing convincing evidence for natural hybridization between T. sebifera and T. cochinchinensis, and between T. sebifera and T. rotundifolia. The chloroplast gene sequences of both hybrids were identical with that of T. sebifera, suggesting that T. sebifera was the maternal parent of the two hybrids. This is the first report of natural hybridization in Triadica, and the hybrids identified in this study should be a good starting point for further hybridization-based breeding in T. sebifera.  相似文献   

20.
The phylogeny of Celastraceae tribe Euonymeae (∼230 species in eight genera in both the Old and New Worlds) was inferred using morphological characters together with plastid (matK, trnL-F) and nuclear (ITS and 26S rDNA) genes. Tribe Euonymeae has been defined as those genera of Celastraceae with generally opposite leaves, isomerous carpels, loculicidally dehiscent capsules, and arillate seeds (except Microtropis). Euonymus is the most diverse (129 species) and widely cultivated genus in the tribe. We infer that tribe Euonymeae consists of at least six separate lineages within Celastraceae and that a revised natural classification of the family is needed. Microtropis and Quetzalia are inferred to be distinct sister groups that together are sister to Zinowiewia. The endangered Monimopetalum chinense is an isolated and early derived lineage of Celastraceae that represents an important component of phylogenetic diversity within the family. Hedraianthera is sister to Brassiantha, and we describe a second species (Brassiantha hedraiantheroides A.J. Ford) that represents the first reported occurrence of this genus in Australia. Euonymus globularis, from eastern Australia, is sister to Menepetalum, which is endemic to New Caledonia, and we erect a new genus (Dinghoua R.H. Archer) for it. The Madagascan species of Euonymus are sister to Pleurostylia and recognized as a distinct genus (Astrocassine ined.). Glyptopetalum, Torralbasia, and Xylonymus are all closely related to Euonymus sensu stricto and are questionably distinct from it. Current intrageneric classifications of Euonymus are not completely natural and require revision.  相似文献   

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