Compositae
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Substances present in plants are used for therapeutic and cosmetic purposes. Some of them can however irritate the skin or hypersensitivity may develop. Potent plant sensitizers are present in oily resins, in particular in the group of volatile oils. The latter are a mixture of volatile and usually fragrant substances which among others contain terpenes. The latter are closely related to isoprene (2-methyl-1.3-butadiene). By combination of two or more isoprene units various terpenes are formed. Potent sensitizers are found in particular among mono- and sesquiterpenes and among them in particular the group of sesquiterpenic lactones is of interest under our conditions as it is the basis for the possible development of sensitization of the eczema type after contact with plants of the Asteraceae-Compositae family. To detect contact sensitization to sesquiterpenic lactones also commercially prepared allergen mixtures can be used („Sesquiterpene-lactone-Mix" 0.1% in petroleum jelly) which is part of the European standard series of Trolab allergens of Hermal Co.
Understanding transcontinental biogeographic patterns has been one of the main foci of the field of biogeography. While multiple explanations for transcontinental disjunctions have been proposed, little is still known about the relative importance of intrinsic and extrinsic traits for the diversification dynamics of disjunct taxa. Here, we study the evolutionary history of the genus Picris L. (Compositae), a great model for investigating the diversification dynamics of transoceanic bipolar disjunct organisms. Ancestral state reconstructions indicate that the most recent common ancestor (MRCA) of Picris was a semelparous and heterocarpic herb that lived in unpredictable environments of North Africa and West Asia. Diversification analyses suggest a significant shift in speciation ca. 1 million years ago, likely associated with the onset of the mid-Pleistocene revolution. Longevity characters are correlated with the evolution of particular fruit types and with environmental conditions. Heterocarpic species are mostly semelparous herbs strongly linked with unpredictable habitats, while homocarpic taxa are mostly iteroparous plants occurring in predictable environments. Binary-state speciation and extinction analyses suggest that homocarpy, iteroparity, and habitats predictability accelerate diversification. Although the combination of homocarpy and iteroparity evolved in several lineages, only members of the P. hieracioides group were able to colonise Eurasia and expand to Australia by transoceanic dispersal. Those findings indicate that large-scale colonisation events depend on a complex interplay of intrinsic and extrinsic factors.
- MeSH
- Asteraceae klasifikace MeSH
- Bayesova věta MeSH
- biodiverzita * MeSH
- biologické modely MeSH
- fenotyp MeSH
- fylogeneze MeSH
- fylogeografie MeSH
- kvantitativní znak dědičný MeSH
- podnebí * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Asie MeSH
- Austrálie MeSH
- severní Afrika MeSH
BACKGROUND AND AIMS: Pilosella officinarum (syn. Hieracium pilosella) is a highly structured species with respect to the ploidy level, with obvious cytogeographic trends. Previous non-collated data indicated a possible differentiation in the frequency of particular ploidy levels in the Czech Republic and Slovakia. Therefore, detailed sampling and ploidy level analyses were assessed to reveal a boundary of common occurrence of tetraploids on one hand and higher ploids on the other. For a better understanding of cytogeographic differentiation of P. officinarum in central Europe, a search was made for a general cytogeographic pattern in Europe based on published data. METHODS: DNA-ploidy level and/or chromosome number were identified for 1059 plants using flow cytometry and/or chromosome counting on root meristem preparations. Samples were collected from 336 localities in the Czech Republic, Slovakia and north-eastern Hungary. In addition, ploidy levels were determined for plants from 18 localities in Bulgaria, Georgia, Ireland, Italy, Romania and Ukraine. KEY RESULTS: Four ploidy levels were found in the studied area with a contrasting pattern of distribution. The most widespread cytotype in the western part of the Czech Republic is tetraploid (4x) reproducing sexually, while the apomictic pentaploids and mostly apomictic hexaploids (5x and 6x, respectively) clearly prevail in Slovakia and the eastern part of the Czech Republic. The boundary between common occurrence of tetraploids and higher ploids is very obvious and represents the geomorphologic boundary between the Bohemian Massif and the Western Carpathians with the adjacent part of Pannonia. Mixed populations consisting of two different ploidy levels were recorded in nearly 11% of localities. A statistically significant difference in a vertical distribution of penta- and hexaploids was observed in the Western Carpathians and the adjacent Pannonian Plain. Hexaploid populations tend to occur at lower elevations (usually below 500 m), while the pentaploid level is more or less evenly distributed up to 1000 m a.s.l. For the first time the heptaploid level (7x) was found on one site in Slovakia. In Europe, the sexual tetraploid level has clearly a sub-Atlantic character of distribution. The plants of higher ploidy level (penta- and hexa-) with mostly apomictic reproduction prevail in the northern part of Scandinavia and the British Isles, the Alps and the Western Carpathians with the adjacent part of Pannonia. A detailed overview of published data shows that extremely rare records on existence of diploid populations in the south-west Alps are with high probability erroneous and most probably refer to the closely related diploid species P. peleteriana. CONCLUSIONS: The recent distribution of P. officinarum in Europe is complex and probably reflects the climatic changes during the Pleistocene and consequent postglacial migrations. Probably both penta- and hexaploids arose independently in central Europe (Alps and Carpathian Mountains) and in northern Europe (Scandinavia, Great Britain, Ireland), where the apomictic plants colonized deglaciated areas. We suggest that P. officinarum is in fact an amphidiploid species with a basic tetraploid level, which probably originated from hybridizations of diploid taxa from the section Pilosellina.
- MeSH
- Asteraceae klasifikace genetika MeSH
- genetická variace * MeSH
- ploidie * MeSH
- průtoková cytometrie MeSH
- rozmnožování genetika fyziologie MeSH
- zeměpis * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Geografické názvy
- Česká republika MeSH
- Evropa MeSH
- Slovenská republika MeSH
We investigated genetic variation and evolutionary history of closely related taxa of Picris subsect. Hieracioides with major focus on the widely distributed P. hieracioides and its closely related congeners, P. hispidissima, P. japonica, P. olympica, and P. nuristanica. Accessions from 140 sample sites of the investigated Picris taxa were analyzed on the infra- and the inter-specific level using nuclear (ITS1-5.8S-ITS2 region) and chloroplast (rpl32-trnL(UAG) region) DNA sequences. Genetic patterns of P. hieracioides, P. hispidissima, and P. olympica were shown to be incongruent and, in several cases, both plastid and nuclear alleles transcended borders of the taxa and genetic lineages. The widespread P. hieracioides was genetically highly variable and non-monophyletic across both markers, with allele groups having particular geographic distributions. Generally, all gene trees and networks displayed only a limited and statistically rather unsupported resolution among ingroup taxa causing their phylogenetic relationships to remain rather unresolved. More light on these intricate evolutionary relationships was cast by the Bayesian coalescent-based analysis, although some relationships were still left unresolved. A combination of suite of phylogenetic analyses revealed the ingroup taxa to represent a complex of genetically closely related and morphologically similar entities that have undergone a highly dynamic and recent evolution. This has been especially affected by the extensive and recurrent gene flow among and within the studied taxa and/or by the maintenance of ancestral variation. Paucity of phylogenetically informative signal further hampers the reconstruction of relationships on the infra- as well as on the inter-specific level. In the present study, we have demonstrated that a combination of various phylogenetic analyses of datasets with extremely complex and incongruent phylogenetic signal may shed more light on the interrelationships and evolutionary history of analysed species groups.
- MeSH
- analýza polymorfismu délky amplifikovaných restrikčních fragmentů MeSH
- Asteraceae klasifikace genetika MeSH
- biodiverzita MeSH
- datové soubory jako téma MeSH
- DNA rostlinná MeSH
- fylogeneze MeSH
- fylogeografie MeSH
- genetická vazba * MeSH
- genetické markery MeSH
- hybridizace genetická * MeSH
- intergenová DNA MeSH
- molekulární evoluce * MeSH
- molekulární sekvence - údaje MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Z etanolového extraktu nerozvinutých púčikov Cynara cardunculus L. (Asteraceae) sa izolovalapigenín-7-metylglukuronid a kyselina chlorogénová. Identita izolovaných látok sa potvrdila nazáklade spektrálnych údajov, porovnaním s autentickými vzorkami a hodnotami uvedenými v lite-ratúre.
From an ethanolic extract of the flower buds of Cynara cardunculus L. (Asteraceae), apigenin-7--methylglucuronide and chlorogenic acid were isolated. The isolated compounds were identified byspectroscopic means, by comparison with authentic samples and literature data.
Z etanolového extraktu nerozvinutých púčikov Cynara cardunculus L (Asteraceae) sa izolovali dvamonodezmozidové saponíny-cynarasaponín B a nový cynarasaponín K. Ich štruktúra bola určenána základe spektrálnych meraní, porovnaním údajov v literatúre a chromatografickým porovnanímso štandardami.
From an ethanolic extract of the flower buds of Cynara cardunculus L. (Asteraceae), two monodes-mosidic saponins, cynarasaponin B and a new cynarasaponin K, were isolated. The isolatedcompounds were identified by spectroscopic means and by comparison with standards and theliterature data.
Triterpénové saponíny ursánového a oleánového typu izolované z nerozvinutých púčikov Cynaracardunculus L. (Asteraceae), boli testované na pôsobenie na komplementový systém. Zistila sainhibičná aktivita bidezmozidových saponínov na aktiváciu komplementu klasickou cestou. Tátoaktivita bola vyššia ako u monodezmozidových saponínov, kým esterifikácia karboxylovej skupinyglukurónovej kyseliny v cukornom reťazci mala za následok signifikantné zníženie antikomplementovejaktivity.
Triterpene saponins of ursane and oleane type isolated from the involucral bracts of Cynaracardunculus L. (Asteraceae) were investigated in in vitro assays for their activity on the complementsystem. The anticomplementary activity of bidesmosidic saponins on the classical pathway activationof the complement was higher than the activity of monodesmosidic saponins, but esterificationof the carboxylic group of glucuronic acid in the sugar residue resulted in a significant decrease inanticomplementary activity.
