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1.
Molecular markers including inter simple sequence repeats (ISSR) and 18S rDNA gene sequence markers were combined with a detailed morphological analysis to seek characters that discriminate four taxa of Portulaca oleracea s.l. These taxa were identified as the microspecies Portulaca nitida, Portulaca oleracea, Portulaca rausii and Portulaca granulatostellulata. Morphological characters did not provide a clear distinction among the four taxa of P. oleracea s.l. It was found that mixed populations of the taxa occur in several locations and morphological similarities between the microspecies were detected. ISSR analysis indicates that gene flow among populations of different taxa was high and most of the genetic variation (61.9%) occurs within population. These results are inconsistent with the general characteristics of P. oleracea as a self- or 5% cross-pollinated species. A close relationship between P. oleracea, P. rausii and P. granulatostellulata was supported by ISSR and 18S rDNA gene sequence. The ISSR and 18s data support the specific status of P. nitida as a recently evolved taxon. We conclude that P. oleracea exists as a polymorphic species and is not divisible into microspecies based on seed surface as the primary morphological trait, and inter simple sequence repeats (ISSR) and 18S rDNA gene sequence markers. We suggest that the taxa do not merit specific rank as morphological characters and absence of a breeding barrier fail to separate the different populations when they become sympatric.  相似文献   

2.
The morphological differentiation and taxonomic treatment of lowland and high-mountain morphotypes within the Solidago virgaurea group are controversial. To clarify the taxonomic status of these taxa, we conducted a morphometric analysis of 1,746 individuals from 80 localities along an altitudinal gradient from the lowlands of northern Poland to the Carpathians and Sudetes of southern Poland. Multivariate morphometric analyses, cluster analyses and principal component analyses, were used to examine the morphological differentiation within the S. virgaurea group in Poland. Canonical discriminant analysis was applied to determine the morphological characters that best discriminate among the taxa. The stability of the high-mountain Solidago minuta morphotype was tested in an experimental field established in lowland Poland; individuals transplanted from various mountain sites were cultivated at this site, and the morphotypes remained stable in terms of their floral and vegetative characters. Multivariate analyses revealed two morphologically distinct taxa in the S. virgaurea group, which correspond to lowland S. virgaurea s. str. and high-mountain S. minuta as recognised in some European floras. The most important morphological characters for distinguishing the taxa are the number of tubular florets per capitulum, inner involucral bract width and involucre height. Vegetative and inflorescence characters appear to have less taxonomic value because they changed continuously with altitude. A key for identifying S. virgaurea and S. minuta in Poland is presented.  相似文献   

3.
The Aloysia gratissima complex is a group of 22 accepted, specific and infraspecific taxa, the boundaries of which are controversial. Various different authors have chosen different characters as criteria for delimiting taxa in this complex, which has been reflected in the variable number of accepted species. To resolve the taxonomy of this group, a modified population aggregation analysis, based on the phylogenetic species concept, was employed. As a result, the Aloysia gratissima complex is here circumscribed as compromising only four species, A. decipiens, A. gratissima s.s., A. oblanceolata and A. schulziana. These species are sustained by a different combination of four characters, of the 16 qualitative attributes analysed. A new approach based on cluster analysis is proposed here delimiting varieties. As a consequence two varieties, supported by significant differences in quantitative characters, are recognized here: A. gratissima var. gratissima and A. gratissima var. sellowii. A complete taxonomic revision of the accepted taxa is presented and six new synonyms are proposed. A key, illustrations and geographical distribution maps are included. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2016, 180 , 193–212.  相似文献   

4.
Forty-nine morphological characters were scored or measured on 44 populations (376 individuals) of Viola subsect. Viola from the West Carpathians and adjacent areas (Slovakia, Czech Republic, Austria and Hungary). The presence of six species, namely V. alba (represented by subsp. alba), V. ambigua, V. collina, V. hirta, V. odorata and V. suavis s.l. was revealed based on pollen fertility, cytological and morphometric analyses. The morphological characters traditionally used to delimit taxa within the subsection and those revealed by our study as most reliable are widely discussed. A key for identifying the taxa and most common hybrids of subsection Viola occurring in the West Carpathians is presented. Chromosome counting and flow cytometry were used to determine the ploidy levels of the populations studied. All individuals of V. alba subsp. alba, V. collina, V. hirta and V. odorata were tetraploid, while those of V. ambigua and V. suavis s.l. were octoploid.  相似文献   

5.
Delimitation of sections is controversial within the genus Cytisus L. (Fabaceae, Genisteae). A morphological study has been conducted on 19 taxa from sections Alburnoides, Spartopsis and Verzinum to clarify their discrimination. Thirty-five quantitative and qualitative characters were recorded on a maximum of 15 dry or living flowers per taxon. Three multiple correspondence factor analyses (MCFA) were performed on a matrix based on 22 of the 35 recorded morphological characters to (1) compare the variability within and between individuals and (2) distinguish groups among the studied taxa. MCFA showed that both flowers sampled from the same plant or different individuals could represent the morphological variability of a taxon. MCFA also clustered the 19 taxa into three groups corresponding to sections Alburnoides, Spartopsis and Verzinum as defined by Cristofolini and Troia (Taxon 44:733–746, 2006). However, floral morphology has not been sufficient to discriminate taxa within sections. A key of the three studied sections based on floral characters is given.  相似文献   

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The work represents the second part of the study pertaining to the definition of the genus Eurotestudo. The first part (Ann. Pal. 2006, 92 (3)) concentrated on the introduction to the subject and to the reporting of the morphological data, on which the definition is based. In this second part, results from the cladistic analysis are presented. All the results which are based on a morphological study, justifying the separation of three lineages previously included in Testudo s.l., are examined. External characters derived from extant forms, and congruent with the definition of the genus and its separation from two other taxa, Testudo and Agrionemys (which are redefined), are also presented. The text is followed by appendices listing the examined taxa and materials.  相似文献   

8.
The Northeast Atlantic and Mediterranean skates (Rajidae) showed remarkable species diversity but with high morphological and ecological conservatism. Since skates are particularly vulnerable to the bottom trawl fishery, species-specific demographic surveys as well as studies defining life history and evolutionary traits are important in prioritising conservation programs. However, the identification of juveniles and adults of some species may be difficult using referenced guidelines and identification keys. Therefore, we attempt to develop markers for species identification through the parallel analysis of a 16S rDNA gene sequence and of several morphological characters on 135 individuals collected by trawl surveys in the Adriatic Sea and putatively assigned to six taxa. Species-specific haplotypes were defined for Raja miraletus, Raja montagui, Dipturus oxyrinchus, since a solid accordance between species boundaries and well-differentiated haplotypes was observed. Comparative analysis of 16S rDNA sequences allowed the identification of three juvenile specimens of Leucoraja circularis, a species that rarely occurs in the Adriatic Sea. On the contrary, morphological traits and haplotype distribution were largely discordant in Raja asterias and R. clavata. While all putative R. clavata individuals showed a unique haplotype (H-CLA), only 8 of 30 putative R. asterias individuals possessed a second weakly divergent haplotype (H-AST). The remaining 22 R. asterias carried the H-CLA. The multivariate analyses of morphometric and meristic characters in putative R. clavata and R. asterias revealed the clustering of individuals regardless of haplotypes. However, a bimodal distribution of R. asterias and R. clavata samples would suggest that two separated taxa might exist, both sharing the two 16S rDNA haplotypes. The haplotype distribution appeared to be significantly correlated only to the standardised disc length/total length (DL/TL) variation. Three alternative explanations may support this scenario: (i) an incomplete lineage sorting process in two morphologically yet distinct taxa; (ii) a recent hybridisation between the two taxa; (iii) the two taxa are morphologically plastic species and all considered morphological characters may be misleading in discriminating between them at all maturity stages, except for the DL/TL. However, further analyses on larger data sets and using molecular key markers (i.e. nuclear genes) will be needed to definitely resolve the status of these taxa. Molecular relationships among rajid taxa are largely consistent with systematics based on internal and external anatomical features. This multidisciplinary study contributed to defining the pattern of species diversity and abundance of rajids in the Adriatic Sea.  相似文献   

9.
Pollen grains of 47 taxa of Campanulaceae including 35 taxa of Campanula that represent its five subgenera and nine sections are investigated. Moreover, five species and three subspecies representing three sections in Asyneuma and one species of each genera Legousia, Michauxia, Zeugandra and Theodorovia were studied by light and scanning electron microscopy. The basic shape of the pollen grains was spheroidal. The apertures vary from tri- to hexa-porate. The sculpturing pattern of exine was rugulate-echinate, rugulate-microechinate or in few species rugulate-microreticulate and microechinate. The most valuable characters for subgeneric classification were the length and density of echini. The length of echini were significantly long (> 2 μm) in C. sclerotricha, Legousia falcata and Michauxia laevigata. Pollen grains show low variation in different species of subgen. Rapunculus, but were variable among different species of some groups, such as sect. Rupestres, probably indicating their non-monophyly despite homogeneity with respect to other morphological characters. Pollen morphology does not support recognition of Asyneuma, Legousia, Michauxia, Symphyandra, Theodorovia, and Zeugandra as separated from Campanula, since none of them exhibit any unique feature.  相似文献   

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Previous taxonomic assessments of the hydrophytic genus Nuphar Sm. (Nymphaeaceae) have inadequately considered the range of morphological variation existing in the genus. A comprehensive statistical analysis of morphological features among the recognized taxa of Nuphar is presented here, first using 10 fruit characters to delimit the separation of two infrageneric groups of taxa, and secondly using 31 characters to quantify the morphological variation found within sect. Nuphar. Results from combined phenetic analyses provided empirical support for recognition of two infrageneric groups of species in the genus (largely by fruit, stigmatic disk margin, neck, and stigmatic disk size) and for separation of taxa within sect. Nuphar (by leaf size, and fruit disk and neck size). Statistical analyses demonstrate that extensive variation in ranges of character states exists among sect. Nuphar taxa. However, a suite of qualitative and quantitative characters can be used to recognize five species and three subspecies within this predominantly Old World assemblage.  相似文献   

13.
Species delimitation studies based on integrative taxonomic approaches have received considerable attention in the last few years, and have provided the strongest hypotheses of species boundaries. We used three lines of evidence (molecular, morphological, and niche envelopes) to test for species boundaries in Peruvian populations of the Liolaemus walkeri complex. Our results show that different lines of evidence and analyses are congruent in different combinations, for unambiguous delimitation of three lineages that were “hidden” within known species, and now deserve species status. Our phylogenetic analysis shows that L. walkeri, L. tacnae and the three new species are strongly separated from other species assigned to the alticolor-bibronii group. Few conventional morphological characters distinguish the new species from closely related taxa and this highlights the need to integrate other sources of data to erect strong hypothesis of species limits. A taxonomic key for known Peruvian species of the subgenus Lioalemus is provided.  相似文献   

14.
Seed protein analysis and morphological characterization were carried out in one cultivated and one wild species of Sesamum, Sesamum indicum L. and S. occidentale Regel and Heer. Data on 13 quantitative and 33 qualitative characters of the cultivated species and seven accessions of the wild taxa were analyzed. The genetic diversity of the taxa was assessed using UPGMA dendrogram and one-way ANOVA (p?<?0.05). Principal component analysis (PCA) was executed to identify the significant characters to delimit the taxa. Seed protein analysis showed diverse bands, ranging from 16 to 88?kDa. A dendrogram based on UPGMA analysis of seed protein suggested intraspecific relationships of the wild taxa as evidenced from the morphological characterization.  相似文献   

15.
Comparative phylogenetic analysis of the small subunit rDNA sequence of Octosporea muscaedomesticae (Flu, 1911) (type species) (Microsporidia) isolated from the blowfly Phormia regina (Diptera:Calliphoridae) is presented. Neighbor Joining bootstrap, Maximum Parsimony and Maximum Likelihood analyses with 38 microsporidian taxa representing five major clades of Microsporidia placed O. muscaedomesticae on a separate branch within a clade containing parasites of freshwater hosts. O. muscaedomesticae differed from Octosporea bayeri, a parasite of the microcrustacean, Daphnia magna (Cladocera:Daphniidae) by 29% demonstrating that the latter microsporidium is not closely related to the type species at the generic level, and should not be placed within the genus Octosporea, a conclusion that is further supported by morphological and developmental differences. Considering the number of disparately related hosts from which Octosporea species have been previously described based mostly on developmental and morphological characters it is likely that many will not fit the current definition of the genus, and it is possible that molecular analysis of these species will show that this genus as defined represents a polyphyletic grouping of unrelated taxa.  相似文献   

16.
The new species Boletus mendax of sect. Luridi is reported and discussed; its morphological, anatomical and edaphic characters are described and a molecular investigation is carried out in order to elucidate the separation from neighboring taxa. The present research also demonstrates the high degree of segregation of two collections of the recently described Boletus comptus and the low taxonomic value of the usual reddish pigmentation of the subhymenophoral layer (the so called Bataille’s line) for both taxa B. mendax and B. luridus. Colour pictures taken in habitat of the taxa presented herein are also provided. Finally, according to an ITS analysis, sect. Luridi is shown to be polyphyletic and the importance of morphological features as stipe ornamentation, context colour beneath tubes and amyloid reaction in stipe base is discussed.  相似文献   

17.
Previous systematic treatments of Menonvillea recognized a group of six morphologically related species, the ‘M. scapigera group,' distinguished by having pinnately lobed leaves and united filaments of median staminal pairs. The number of recognized species ranged from six to two, one with three subspecies. In order to clarify the taxonomy of this group, multivariate and univariate analyses of qualitative and quantitative characters from herbarium specimens were performed. Additionally, to test the morphological results, the phylogenetic relationships and degree of exclusive ancestry were studied using ITS sequences and the genealogical sorting index. Our results support the recognition of three species (M. famatinensis, M. hirsuta, M. scapigera) delimited by a unique combination of qualitative characters. Quantitative characters support the division of the latter species into two subspecies: scapigera and longipes. The molecular data are congruent with the morphology and support the inclusion of M. hookeri within M. scapigera. A key to taxa of the M. scapigera group is presented.  相似文献   

18.
Acoustic and morphological characters are very important to distinguish species of Cicadidae. In this study, the morphological and acoustic characters of Cicadatra platyptera Fieber, 1876 (Hemiptera, Cicadidae) collected from Turkey were analysed. The external morphological structures of two species were drawn and photographs of some specimens were taken. We evaluated taxonomically important morphological characters such as body shape, colors, patterns, structure, and genital structure. We evaluated measurements of external morphological structures and acoustics characters of Cicadatra platyptera from Turkey, partly with statistical analyses. Morphological characters were compared and differentiated from the closely related species, Cicadatra atra. The distribution in Turkey including previous records and the material examined were shown on a map, and the distribution in Palearctic Region was given.  相似文献   

19.
Questions surround the mechanism of mutually exclusive expression by which Plasmodium falciparum mediates activation and silencing of var genes. These encode PfEMP1 proteins, which function as cytoadherent and immunomodulatory molecules at the surface of parasitised erythrocytes. Current evidence suggests that promoter silencing by var introns might play a key role in var gene regulation. To evaluate the impact of cis-acting regulatory regions on var silencing, we generated P. falciparum lines in which luciferase was placed under the control of an UpsA var promoter. By utilising the Bxb1 integrase system, these reporter cassettes were targeted to a genomic region that was not in apposition to var subtelomeric domains. This eliminated possible effects from surrounding telomeric elements and removed the variability inherent in episomal systems. Studies with highly synchronised parasites revealed that the UpsA element possessed minimal activity in comparison with a heterologous (hrp3) promoter. This may result from the integrated UpsA promoter being largely silenced by the neighbouring cg6 promoter. Our analyses also revealed that the DownsA 3′ untranslated region further decreased the luciferase activity from both cassettes, whereas the var A intron repressed the UpsA promoter specifically. By applying multivariate analysis over the entire cell cycle, we confirmed the significance of these cis-elements and found the parasite stage to be the major factor regulating UpsA-promoter activity. Additionally, we observed that the UpsA promoter was capable of nucleating reversible silencing that spread to a downstream promoter. We believe these studies are the first to analyse promoter activity of Group A var genes, which have been implicated in severe malaria, and support the model that var introns can further suppress var expression. These data also suggest an important suppressive role for the DownsA terminator. Our findings imply the existence of multiple levels of var gene regulation in addition to intrinsic promoter-dependent silencing.  相似文献   

20.
European annual species of the genus Rhinanthus often exhibit seasonal ecotypic variation, a phenomenon also known from related genera of hemiparasitic Orobanchaceae. Populations with different flowering times exist, correlated with differences in a number of morphological characters. The present study evaluates the correlation of morphological characters and genetic differentiation of populations of Rhinanthus alectorolophus. Thirty-nine populations of three different subspecies from southwestern Germany were sampled. A total of 798 individuals were used for morphological analyses and 187 of these for AFLP analyses. Principal component analysis showed that morphological variation is mostly continuous. In a discriminant analysis based on morphological characters, only 89.7 % of all individuals were correctly assigned to their previously determined subspecies, indicating that subspecies identification is ambiguous for some populations. Using AFLP data and Bayesian assignment analysis, the sampled individuals could be grouped in three genetic clusters which do not correspond to the three subspecies. Instead, the clustering shows a clear geographic pattern and a Mantel test likewise revealed a significant correlation between genetic and geographic distances. Correlations of genetic distances with differences in morphological characters were weak and mostly insignificant. The results indicate that the subspecies of R. alectorolophus do not form discrete entities and that the character combinations distinguishing them are homoplastic.  相似文献   

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