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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Morfologická a genetická variabilita v populacích Gymnadenia conopsea agg. / Morphological and genetic variation in populations of Gymnadenia conopsea agg.

KOLOUŠKOVÁ, Pavla January 2010 (has links)
The complex Gymnadenia conopsea s.l. represents a very problematic group in terms of taxonomy, showing a wide morphological, phenological, genetical and cytogenetical variability. The aggregate G. conopsea encompasses a range of taxa, two of which, G. conopsea (L.) R. Br. s.s. and G. densiflora (Wahlenb.) A. Dietr., have been acknowledged as beeing a species level. Individual taxa cannot be safely distinguished on the basis of morphological characteristics in all cases. Recently, there has been a lot of discussion concerning the taxonomical value of taxons within the G. conopsea complex. The complex is represented by a variety of cytotypes, while the major tetraploid cytotypes represent the above mentioned G. conopsea and G. densiflora taxa, that are easily distinguishable by means of flow cytometry. The taxonomical classification of minority cytotypes is not clear. For these reasons, to be able to obtain more detailed information, an application of different approaches from the field of morphology, cytogenetics and molecular genetics is suitable when evaluating the populations. In this thesis, morphological characteristics, AFLP and an analysis of microsatellites along with a measurement of ploid level using FCM have been used for evaluation. On the basis of evaluating a multidimensional cluster analysis and a dendrogram created by the UPGMA method combining these data, a specific dissimilarity of the G. densiflora and G. conopsea taxon has been confirmed. Based on the comparative analysis of microsatellite loci and overlapping morphometric characteristics of tetraploid and octoploid G. conopsea cytotype it can be assumed that the octoploid cytotype is a separate chromosomal aberration of tetraploid plants.
2

Das Diskriminierungsverbot im Zivilrecht / und seine Auswirkungen auf das rechtsgeschäftliche und quasi-rechtsgeschäftliche Handeln / The discrimination ban in the civil law / and his effects on the contractual and quasi-contractual action

Zeckei, Matthias 19 May 2008 (has links)
No description available.
3

Reprodukční biologie \kur{Achillea millefolium} agg. a \kur{Achillea ptarmica} v lučních a lemových společenstvech / Reproduction of \kur{Achillea millefolium} agg. and \kur{Achillea ptarmica} in meadows and verges

TOMŠOVÁ, Pavla January 2013 (has links)
Several changes in land use during the last 50 years of 20th century had a significant impact on the composition of traditional meadows. The abundance of many plant species typical for traditionally managed meadows has declined. But some of these species have found a refuge in habitats such as field margins and road verges. The aim of this study was to describe how the reproduction success of two related Achillea species A. millefolium agg. and A. ptarmica depends on (i) the particular habitat in which they grow (meadow/verge); (ii) the abundance of pollinators in the study site; and (iii) timing of flowering within the season. Moreover, the longevity of individual flowers of the two taxa has been studied in order assess the width of the time frame the reproduction takes place in. These objectives were achieved by means of measuring plant total seed production and germination as proxies of reproductive success both in meadow and verge populations at the beginning, peak and end of the flowering season of the two species in 2012. The plants were chosen at plots, where concurrently a pollinator survey has been conducted as the part of the broader project. The durations of the male and female phases of individual flowers have been studied in separate experiments.
4

Biosystematická studie okruhu Carlina vulgaris ve střední Evropě s využitím molekulárních a morfometrických metod / Biosystematic study of the Carlina vulgaris complex in Central Europe based on molecular and morphometric approaches

Mašková, Hana January 2018 (has links)
The Carlina vulgaris complex in central Europe includes several lineages defined by their ecology, morphology and distribution. This diploma thesis is focused on relationships between the taxa recognized in the Czech Republic, namely Carlina vulgaris subsp. vulgaris, C. biebersteinii subsp. biebersteinii, C. biebersteinii subsp. brevibracteata and C. biebersteinii subsp. sudetica. Molecular analysis revealed two genetically defined groups. One includes samples from relict populations in western Bohemia and from high mountains classified as C. biebersteinii subsp. biebersteinii and C. biebersteinii subsp. sudetica. The other is represented by plants classified as C. vulgaris and C. biebersteinii subsp. brevibracteata. This genetic differentiation was also confirmed by morphometric analysis. However, relationships within these two groups remain unclear. The Czech populations of Carlina biebersteinii subsp. biebersteinii as well as of C. biebersteinii subsp. sudetica are closely related to the mountain populations in the Alps and Carpathians. Their occurrence in the Czech Republic is relict and they should be in focus of nature conservation. However, the separate taxonomic position of the claimed endemic C. biebersteinii subsp. sudetica is probably unjustified.
5

Evoluční vztahy tetraploidních zástupců skupiny Galium pusillum (sekce Leptogalium) na území střední Evropy. Alopatrická diferenciace českého endemického druhu G. sudeticum. / Evolutionary history of tetraploid representatives Galium pusillum group (sect. Leptogalium) in central Europe. Allopatric differentiation of Czech endemic species G. sudeticum

Knotek, Adam January 2014 (has links)
The presented study tries to reveal the evolutionary history of polyploid complex Galium pusillum aiming on a rare czech endemic species G. sudeticum, an ideal model to study allopatric speciation in the context of Central European (post)glacial development. The species G. sudeticum grows in Krkonose Mts. and on serpentines in western Bohemia (Slavkovský les) more than 200 kilometers away. Our morphological and molecular data suggest a clearly different history of its two isolated areas. The populations in Krkonose Mts. are probable relics of mountainous species G. anisophyllon which was there on its northern border of occurence and hybridized with lowland species G. valdepilosum during postglacial vegetations shifts. This fact is well supported by intermediate position of Krkonose Mts. populations in both morphological and molecular AFLP analyses and by sharing the same chloroplast haplotype with geographically close lowland populations. On the other hand the serpentine lowland populations in western Bohemia are both morphologicaly and genetically indistinguishable from G. valdepilosum. Distinct genetic lineage of few populations belonging to G. valdepilosum (incl. one traditionaly referred as G. sudeticum) was found in western Bohemia and Bavaria, located on relic stands (calcareous and serpentine...
6

Populační struktura a fenotypová diferenciace Campanula moravica / Population cytotype structure and phenotypic variation of Campanula moravica

Šemberová, Kristýna January 2013 (has links)
Polyploidisation plays a major role in plant evolution. It can also cause taxonomic complexities as morphological differences are often blurred in higher ploidy levels. One of the taxonomically-intrigued groups of Central Europe is C. rotundifolia agg. Three ploidy- heterogeneous species are traditionally recognized in the Czech Republic: C. gentilis (2x, 4x), C. rotundifolia (2x, 4x) and C. moravica (4x, 6x). The thesis examines karyological and phenotypic variation of C. moravica, in the centre of its distribution (the Czech Republic and Slovakia). With the aid of modern biosystematics tools (DNA flow cytometry, multivariate morphometrics), marked discrepancies were revealed between published data and actual cytotype distribution pattern and morphological variation. In contrast to literature records, cytotype distribution in C. moravica is largely parapatric, with hexaploids occurring in Pannonian basin and tetraploids in Central and Eastern Slovakia. The type population of presumed tetraploids turned out to be hexaploid. The coexistence of one majority (4x) and six minority cytotypes (2x, 3x, 5x, 6x, 8x, 9x) was found in one population in central Slovakia and represent the most salient case of ploidy coexistence ever reported. Multivariate morphometrics showed that species identification on the...
7

Pátrání po původu vysokohorských endemických zvonků z okruhu Campanula rotundifolia agg. ve střední Evropě. / Searching for the origin of high-altitude endemic harebells from Campanula rotundifolia agg. in central Europe.

Folbrová, Magdaléna January 2019 (has links)
Complex Campanula rotundifolia agg. is rich in endemic species, especially in the high- elevated mountain ranges. Extreme climatic conditions in the subalpine habitats can lead to a convergence in plant's morphology between plants isolated in different mountain ranges. Because of the lack of morphological differentiation, it is very difficult to reconstruct the evolutionary history of bellflowers C. scheuchzeri from the Alps, C. bohemica from the Krkonoše Mountains and C. tatrae from the Western Carpathians. A similarity in morphology and the same ploidy level can suggest vicariance from a large area of an ancestor species. However, regarding the continuous morphological variation, the high-altitudinal endemics could have originated by local adaptation from originally low-land species. DNA-ploidy level and genome size were detected by flow cytometry. Taxonomically important characters were found using multivariate morphometric analysis. The phenotypic plasticity of the taxon C. tatrae was tested by a cultivation experiment. Genetic structure of the studied species was revealed using molecular marker - microsatellites (7 variable primers). Studied taxa were tetraploids, but some possessed different genome size. The morphological differentiation was mainly due to characters like calyx lobes length...
8

Zhodnocení kryptické diverzity ve skupině lakušníku niťolistého (Ranunculus trichophyllus agg.) / Evaluation of cryptic diversity in the group of thread-leaved water-crowfoot (Ranunculus trichophyllus agg.)

Hanzlíčková, Johana January 2021 (has links)
Ranunculus trichophyllus agg. (thread-leaved water crowfoot) represents a taxonomically challenging group of aquatic plants in which the presence of several significantly different genotypes and the genome size variation have been recently revealed. The results of previous studies suggest that cryptic taxa occur in this group, being so far overlooked due to considerable morphological reduction and extensivephenotypic plasticity. In this thesis, the variation and genetic relationships of four morphologically similar homophyllous water-crowfoot species was critically assessed in the area of Central Europe, using a combination of modern biosystematic methods (flow cytometry, direct DNA sequencing, morphometric analyses), specially focusing on the complex of R. trichophyllus.. The genome size analysis via flow cytometry was confirmed as a suitable method for determining the studied species; further, several hybrid combinations were revealed using this approach. However, recent interspecific hybridization is rather infrequent in the interest group. The results of DNA analyses indicate an importance of hybridization events in the evolution of sect. Batrachium: all the polyploid taxa studied are probably of allopolyploid origin. Two cryptic taxa within the traditionally recognized species R. trichophyllus have...
9

Vliv biotických interakcí na populační biologii lučních rostlin / The role of biotic interactions in population biology of meadow plants

Janovský, Zdeněk January 2015 (has links)
In present thesis, I treat the topic of impacts of plant-animal interactions, namely herbivory and pollination, on plant life cycle and lifetime fitness. First, I identify the components of the impact of plant-animal interactions: i) interaction frequency; ii) per-interaction effect; iii) sensitivity of the plant's life cycle to the changes in vital rate impacted by the animals. Furthermore, I also classify other causes changing the outcome of a plant-animal interaction into two categories: i) plant's traits; ii) plant's environment. A review of extant literature on the topic revealed that especially the role of plant's environment in changing the outcome of plant-animal interactions is largely understudied and I attempt to reduce this gap in knowledge in the five detailed studies encompassed in this thesis. The detailed studies focus on a model system of Central European wet grasslands and especially on three species typical to it: Succisa pratensis, Achillea millefolium and A. ptarmica. The first two studies examine the effects of environment on frequency of plant- animal interactions. The next two studies are more integrative, one focusing on the impacts of different herbivore groups on the complete life cycle and the other on interaction of herbivory and pollination on plant lifetime fitness....

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