• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 10
  • 8
  • 4
  • 2
  • 2
  • 1
  • Tagged with
  • 30
  • 9
  • 8
  • 6
  • 5
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 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

Použití jehličnanů na území České republiky na konci 19. a v první polovině 20. století

Mácha, Jakub January 2014 (has links)
Diploma thesis comes out from contemporary offers of nursery enterprises, which offers informations about historical range of some period. In the begining of the thesis is focused on period conditions in the Czech. There is a description a economic, cultural a social condition. The aim of this thesis is to rate identified range of conifers and their use in the period. The thesis also compare the availability of range of the period in offers of domestic nurseries nowdays and presence these taxons in European range. The results of the thesis is finding, that part of historical range is no long available on the fair as well as that contemporary significant increase of range of conifers has been detected.
2

Biologicky aktivní látky vybraných taxonů rodu Mentha L. a možnosti jejich využití v ochraně rostlin

Kaffková, Katarína January 2015 (has links)
Taxa of Mentha L. were evaluated during 2011-2014. Thirty-five taxa were evaluated in terms of morphological parameters, in term of constituents (quantity and quality of essential oil, content of phenols and flavonoids) and insecticidal activity of essential oils on Musca domestica and Culex quinquefasciatus Say. Essential oils were obtained by steam-distillation and their composition was determined by GC/MS. Content of phenolics was evaluated by Folin-Ciocalteu assay, content of flavonoids was determined by aluminium chloride colorimetric assay and antioxidant capacity was determined by DPPH method. Insecticidal activities were evaluated according to the modified WHO methodology. The best insecticidal activity, for Musca and Culex, was observed in case of essential oil with majority stake of piperitenone oxide, namely essential oils obtained form taxa M. suaveolens 'Variegata' and M. sp. 'Cinderella'.
3

Květinové záhony z přímých výsevů

Novosadová, Vladěna January 2015 (has links)
The dissertation dealt with sowing annuals in the establishment of flowerbeds from direct sowing of taxon which are potentially suitable for autumn and spring sowing. In the experimental part was attempted to annuals of direct sowing. There were realized three sowings, in autumn 2013 and 2014 and in spring 2014, when were sown 26 same taxon of the seed. The aim of the experiment was evaluated the germination of seeds, height and flowering taxon, aesthetic effect of fetus, effect of taxon in the composition and suitability growing and seeding taxon. Based on all these results there were performed the comparison and evaluation and the conclusions and recommendations were defined for following experiments and practice. After evaluation all the results, interesting and perspective annuals for directautumn sowing appeared Ammi visnaga (L.) Lam., Bupleurum rotundifolium L., Clarkia pulchella Pursh. 'Mix', Consolida ambiqua (L.) P. W. Ball & Heywod. 'Hyacintokvětá', Nigella damascena L. 'Cramer s Plum', Nigella orientalis L., Papaver rhoeas L. 'Shirley Double Mixed'. There were evaluated the best and the most perspective annuals for direct spring sowing - Borago officinalis L., Bupleurum rotundifolium L., Calendula officinalis L. 'Pacific Beauty Směs', Consolida ambiqua (L.) P. W. Ball & Heywod. 'Hyacintokvětá', Cosmos bipinnatus Car. 'Sonata', Cosmos sulphureus Car. 'Redcrest', Nigella damascena L. 'Cramer s Plum'..
4

Ověření pravosti označení taxonů rodu Origanum L. pomocí metod GC-MC a AFLP

Hradská, Lucie January 2015 (has links)
The aim was to verify the authenticity marking taxa genus Origanum L. The sortments were grown at the experimental plots ZF MENDELU in 2014. The analysis of the evaluation results of the work carriedout was laso done in the same year. The assortments were morphological described. The morphological characters were such as: plant height, leaf size, inflorescence height, color of the leaves and flowers. Further details were recorded on phenological phases of the taxa. Oregano samples were assessed for quantity of essential oils by distillation and the essential oils was then subjected to qualitative evaluation using the GC-MC method. The genetic relationships were evaluated using the AFLP methods.
5

Biogeography and evolution of Melanesian and South Pacific ants

MATOS MARAVÍ, Pável Fortunato January 2016 (has links)
This thesis investigates the systematics, biogeography, and diversification dynamics of a large and ecologically important insect group in SE Asia and the Indo-Pacific region: the ants. This study utilizes a multidisciplinary framework to elucidate the evolutionary history of selected ant clades with the overall aim to shed light on similar ecological and evolutionary processes intervening in ant diversity.
6

The Dawn of a New Age : Interrelationships of Acoela and Nemertodermatida and the Early Evolution of Bilateria

Wallberg, Andreas January 2009 (has links)
Deciphering the rapid emergence of bilaterian animals around the time of the Cambrian Explosion and reconstructing the interrelationships of animal groups have long been two of the most elusive problems in Zoology. This thesis concerns the phylogenetic interrelationships within and among Acoela and Nemertodermatida, two groups of small worms that are believed to be basal bilaterians and which may provide important clues for understanding the early evolution of animals. In addition to trying to resolve the phylogenetic positions of these groups, major focus is put on inferring how ancestral animals might have looked, given the phylogenetic hypotheses put forward. The data used to infer phylogenies include nuclear ribosomal DNA, the mitochondrial COI gene and microRNAs. Based on phylogenetic analyses of a large number of 18S SSU ribosomal DNA sequences, it is proposed that Cnidaria is the sister taxon to Bilateria. Poor taxon sampling is suggested to be one of the reasons for why earlier assessments of the interrelationships among the most basal animal groups have yielded many conflicting results using the same gene. Analyses of new 18S SSU rDNA and 28S LSU rDNA sequences from six of the nine known species of nemertodermatids corroborate earlier indications that Acoela and Nemertodermatida are not sister taxa, as once thought. Being separate basal bilaterian animal groups, it is suggested that the last common ancestor of all bilaterians shared much of their comparatively simple morphology. Many methods are deployed to assess whether the phylogenetic results are mainly due to long-branch attraction, but no indication of this artifact is detected. The first comprehensive phylogenetic framework of Acoela is reconstructed from the 18S SSU, 28S LSU and COI genes, in combination with morphological data. The ancestral acoel worm is reconstructed using Bayesian methods and morphological observations in extant species. Two indeces, posterior similarity and reconstruction signal, are implemented to assess how similar different species are to the last common ancestor of all acoels and illustrate how clearly different characters or nodes are reconstructed. It is suggested that the ancestral acoel looked much like extant species of Diopisthoporus. The phylogenetic positions of Acoela and Nemertodermatida are assessed using new data on microRNAs in the acoel Hofstenia miamia and the nemertodermatid Meara stichopi. Acoela and Nemertodermatida are again found to be basal bilaterians, in congruence with earlier results. Using the work-flow and indeces developed earlier, it is concluded that the bilaterian ancestral microRNA repertoire can not yet be reconstructed with high confidence. All papers stress the importance of inclusive taxon sampling for making generalized inferences about ancestral features in animals.
7

Samovolné šíření introdukovaných dřevin v zámeckém parku v Lednici

Hutko, Tomáš January 2019 (has links)
This thesis deals with the introduction of woody plants from the past to the present. In addition to basic terminology, it focuses on the biological nature of generative and vegetative distribution of plants, especially woody plants. It addresses the spontaneous spread of non-native plant taxa, especially woody plants in the Czech and Slovak Republics. It provides a broader view of the benefits and negatives, both from the point of view of landscape architecture and from other disciplines, within the scope of deliberately using or suppressing this property. It solves the general regime and specifics within the possibility of their suitable cultivation, both in parks and in the open country. The practical part of the thesis is focused on the creation of the methodology of field investigation for the registration of individual taxa selection in the park. With the help of the developed method of field investigation it focuses on the taxa of introduced woody plants in the Lednice park. In the results, it provides a set of individualized inventory items, along with some of them, and then interpreting the results using graphs and tables. Part of the results is also a graphically processed map from the field survey by locating the evaluated items in the park.
8

Beyond Building A Tree: Phylogeny Of Pitvipers And Exploration Of Evolutionary Patterns

Fenwick, Allyson 01 January 2012 (has links)
As generic and higher-scale evolutionary relationships are increasingly well understood, systematists move research in two directions: 1) understanding specieslevel relationships with dense taxon sampling, and 2) evaluating evolutionary patterns using phylogeny. In this study I address both foci of systematic research using pitvipers, subfamily Crotalinae. For direction one, I evaluate the relationships of 96% of pitvipers by combining independent sets of molecular and phenotypic data. I find the inclusion of species with low numbers of informative characters (i.e. less than 100) negatively impacts resolution of the phylogeny, and the addition of independent datasets has no effect on or a small benefit to confidence in estimated evolutionary relationships. Combined evidence is extremely useful in evaluating taxonomy; I use it with South American bothropoid pitvipers. Previous work found the genus Bothrops paraphyletic, but no study had included enough species to propose a taxonomic resolution. I resolve the relationships of 90% of bothropoid pitvipers, and support the paraphyly of Bothrops as previously defined, but find it consists of three well-supported clades distinguished by distinct habitats and geographic ranges. I propose the division of Bothrops sensu lato into three genera. To address research direction two, I investigate the change in reproductive mode from egg-laying (oviparity) to livebearing (viviparity) in vipers, as well as the expansion of pitvipers through South America. I resolve the phylogeny and the divergence times for subgroups of interest then use model comparison and ancestral character state or iv geographic range estimation to trace the evolution of reproductive mode or geographic range across evolutionary history. For vertebrates, the predominant explanation for the evolution of reproductive mode is Dollo’s Law of unidirectional evolution. This law has been challenged for a number of characters in different systems, but the phylogenetic methods that found those violations were criticized. I find support for unidirectional evolution in two analyses and rejection of it in others, and therefore do not reject Dollo’s Law for the evolution of reproductive mode in vipers. In the case of geographic range, dozens of hypotheses have been proposed to explain the great biodiversity in South America, but tests of these hypotheses are lacking. I define specific time- and space-based predictions for seven hypotheses based on geological and climatic events – uplift of the Andes Mountains, saltwater inundation of inland areas, change in river flow, and Pleistocene climate changes. I find some support for half of the hypotheses, including one allopatric, one parapatric, and one based on climate change. I conclude that the evolution of South American pitvipers is extremely complex. Through fulfillment of both systematic research directions, I generated new knowledge about pitvipers and evolutionary processes. My methods of evaluating evolutionary patterns provide frameworks for different research questions in these areas, and I suggest that other researchers apply similar techniques to evaluate other portions of the Tree of Life
9

Diversity of Eukaryotes and Their Genomes

Wegener Parfrey, Laura Ellen 01 February 2011 (has links)
My dissertation addresses two aspects of eukaryotic evolution, 1) the organization of eukaryotic diversity and 2) genomic variation in Foraminifera. The bulk of eukaryotic diversity is microbial with plants and animals representing just two of the estimated 75 lineages of eukaryotes. Among these microbial lineages, there are many examples of dynamic genome processes. Elucidating the origin and evolution of genome features requires a robust phylogenetic framework for eukaryotes. Taxon-rich molecular analyses provide a mechanism to test hypothesized evolutionary relationships and enable placement of diverse taxa on the tree of life. These analyses result in a well-resolved eukaryotic tree of life. Relaxed molecular clock analyses of this taxon-rich dataset place the origin on eukaryotes in the Paleoproterozoic, and suggest that all of the major lineages of eukaryotes diverged before the Neoproterozoic. This robust scaffold of the tree of eukaryotes is also used to elucidate common themes in genome evolution across eukaryotes. Mapping dynamic genome features onto this tree demonstrates that they are widespread in eukaryotes, and suggests that a common mechanism underlies genome plasticity. Foraminifera, a diverse lineage of marine amoebae, provide a good model system for investigating genome dynamics because they amplify portions of their genome and go through ploidy cycles during their life cycle. Assessment of nuclear dynamics in one species of Foraminifera, Allogromia laticollaris strain CSH, reveals that genome content varies according the life cycle stage and food source, which may differentially impact organismal fitness. The inclusion of diverse microbial eukaryotes enables better resolution of eukaryotic relationships and improves our understanding the dynamic nature of eukaryotic genomes.
10

Phylogeny and Visual System Evolution in Sap Beetles (Coleoptera: Cucujoidea: Nitidulidae)

Powell, Gareth S. 10 December 2021 (has links)
Coleoptera is currently the most diverse lineage of life on Earth with more than 400,000 described species. The group also contains unbelievable ecological and morphological variation that has been evolving since the early Carboniferous (>350 MYA). The group provides the perfect playground to test evolutionary hypotheses with large-scale phylogenies. First, a newly developed bioinformatics tool is presented that allows for the critical assessment of the stability of phylogenetic nodes with even minor changes in taxon sampling (i.e. a single taxon jackknifed). The tool, TANOS, is capable of performing tests on large genomics-scale datasets. The case study included is a widely used phylogenomics effort to resolve the higher level relationships of all Insecta. The specific beetle group chosen for the remaining products is the superfamily Cucujoidea, and more specifically the family Nitidulidae, or sap beetles. Several taxonomic and nomenclatural projects were necessary to provide a more stable classification and begin the process of establishing the group as a model system for questions concerning feeding behavior evolution. Several new species of the genus Carpophilus were described from both the West Indies and the New World tropics and subtropics. Several type designations were also needed for many species in the subfamily Carpophilinae. In addition, the fossil diversity of Nitidulidae was reviewed with the addition of the oldest known member of the Cillaeinae from amber (Dominican). With the reviewed fossil fauna, as well as many more from across the Cucujoidea more broadly, a divergence-time estimated phylogeny was generated for >250 species of the superfamily. The phylogeny, based on the combination of multiple published Sanger datasets and supplemented with newly generated data for a further 50 species, was used to date multiple feeding shifts in the group. Specifically, the clade ages were used to compare with published clade ages for the corresponding food resource each clade is known to exploit. A significant relationship was recovered between age of the beetle clade and the corresponding food resource clade. Interestingly, it was found that clades that shifted to a food resource first, in the absence of existing beetle competitors, were significantly more diverse over subsequent lineages that shifted to the same resource. A feeding ecology of specific importance, at least to many groups of nitidulid, is anthophily, or flower-visiting. An extreme variation in eye size is observable across the family and so multiple factors including; sex, day-night activity, and feeding behavior were tested in a phylogenetic context. No sexual dimorphism nor variation consistent with activity period was found. Relative eye size of flower visiting species was significantly larger than that of all other feeding behaviors in sap beetles. This correlation was also tested in a phylogenetic context, with the increase in morphological investment in vision repeatedly shown to correspond to shifts in flower associated behavior. In an attempt to investigate the interplay between behavior, morphology, and genetics in the same process, opsin data was captured as part of a large targeted enrichment sequencing effort (AHE) across Nitidulidae and their relatives. The first phylogenomic estimate was generated for the group, with a taxon sampling of 192, and data sampling depth of 703 loci. A newly updated pipeline was developed for AHE data and is presented herein. Topological results support the recent idea of a non-monophyletic Cucujoidea. Results also demonstrate multiple classification issues within the Nitidulidae with several new subfamilies/tribes necessary to maintain diagnosable monophyletic groups in the family. The vast majority of sampled genera were supported, with the exception of Brachypeplus and Pallodes. Preliminary opsin diversity across the group is much greater than previously estimated. Opsin copy number is potentially plastic even within individual genera, although consistently duplications are associated with taxa that visit flowers. It is clear that the complexity of cucujoid visual systems increases with anthophilous behavior.

Page generated in 0.0455 seconds