• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 7
  • 1
  • Tagged with
  • 8
  • 5
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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

Dynamika výskytu orchidejí ve vybraném modelovém území v jižních Čechách / Dynamics of orchid occurrence in South Bohemia

Kosánová, Kristina January 2017 (has links)
Orchids are an endangered group of plants, protected both in the Czech Republic and in the whole world. Questions of their protection are therefore lively discussed, but not all factors, affecting their presence, are known so far. The purpose of this work was to find out, which environmental factors influence the existence of certain orchid species at their localities in the selected area. This is important for better protection of orchids, because only by knowing these factors we can find new sites, or improve management plans of the existing ones. Another purpose of this work was to find out what is the main reason for extinction of orchids at their historical localities and whether or not there is a possibility of finding other, yet unknown localities of these species. This thesis is based on data from databases, which were also updated during the data collection. The data were processed by computer software MaxEnt, which produces species distribution models and allows to predict potential occurrence of orchids even at yet unknown localities. This software also analyses the environmental factors affecting species presence. I found that the main reason of extinction of orchids at their historical localities was overgrowing. Main environmental factors affecting orchid occurrence were analysed for...
2

Ekologie orchidejí a dalších potenciálních medicinálních rostlin v Nepálu / Ecology of orchids and other potential pharmaceutical plants in Nepal

Rokaya Timsina, Binu January 2021 (has links)
In this thesis, I focused mainly on orchids and also carried out some research on different pharmaceutically potential plants in Nepal. I compiled both data from field and secondary data sources and one of my first outputs was complete checklist of orchids in Nepal. I also studied distribution patterns and affinities of orchids with different floristic regions in Nepal. My next work on epiphytic orchids is related to diversity, distribution and host- species associations and their future in the context of climate change in Nepal. In addition to this, I also worked on factors affecting epiphytic orchids along an altitudinal gradient in central Nepal. Working on population dynamics of terrestrial orchid species, Crepidium acuminatum, lasted for 6 years. Together with orchids, I determined secondary compounds present in a highly important Nepal endemic medicinal plant, Swertia multicaulis. I also compiled the information on uses, phytochemistry, pharmacology and toxicity of highly important Himalayan endemic medicinal plant, Neopicrorhiza scrophulariiflora. The last research of my Ph.D. project ended up by gathering the information on uses of different medicinal plants, including orchids that were used to treat various gastrointestinal diseases in Nepal. The results of my doctoral thesis are presented...
3

Dynamika výskytu orchidejí ve vybraném modelovém území v horských polohách / Dynamics of orchid occurrence in highlands

Černocká, Veronika January 2018 (has links)
All species of orchids are sensitive plants and records of their distribution are rare. Their rarity is related to their complex biology and their sensitivity to changes in the environment. It is necessary to pay attention to these threatened species, so that we could preserve them from extinction. For their effective protection we need to know the main causes of extinction of their localities. It is also useful to know the factors, which determine their distribution, so that we could find new localities, where they occur. In this thesis I analyzed some climatic, geographic and ecological factors in the Jeseníky mountains and their surroundings. First, I visited localities of orchids, which were registered in large databases of their presence in the past. The four most numerous species were analyzed using the program MaxEnt. Based on the revisions, existence of 2/3 of the revised localities was confirmed, 8% of the revised localities became extinct because of overgrowth or due to human intervention in the landscape. From the MaxEnt results it is clear, that for all species the most important factor at the 50 × 50 m scale, is the type of biotope and heterogeneity of the countryside. The most suitable biotopes are floodplain and wetland forests, mesophile meadows, natural scrubs, peat bogs and...
4

Možnosti kultivace orchideje Macodes petola technikami in vitro / In vitro cultivation possibilities of orchid Macodes petola

SVOBODOVÁ, Simona January 2007 (has links)
The orchid family covers 90 percent of the rarest plants under protection all over the world. The ecological and economic value of orchids has aroused public awareness. Since vegatitve propagation methods are available, development of in vitro methods are essential for conservation and commercialization of plants. Purposes work was elaboration progress of vegetative multiplication for tropical orchid Macodes petola in conditions in vitro. At research were proof 4 methods, which distinguish in using desinfection, in operating time and in using different nutritive mediums.
5

Liší se klíčivost vybraných druhů vstavačovitých rostlin\nl{} na přirozených a obnovených loukách? / Does it differ the germinability of the chosen orchids on the natural and renewed meadows?

SUCHÁČEK, Pavel January 2015 (has links)
The survey presented in this thesis focused on germination of six orchid species in the Protected landscape area White Carpathians; specifically Platanthera bifolia, Neottia ovata, Anacamptis pyramidalis, Gymnadenia conopsea subsp. conopsea, Traunsteinera globosa, Orchis militaris on restored medows of various age. As the control, two National Protected Areas (Zahrady pod Hájem and Čertoryje) were used. The initial stage of germination was detected on both restored and control meadows. The advanced stage of germination (protocorm) was recorded in three species (GC, NO, PB) on restored meadows, and in all species on kontrol meadows. The other aim of the thesis was to determine via molecular methods, which species of mycorrhizal fungi are associated with the model orchid species.
6

Zhodnocení lokalit orchidejí ve vybrané oblasti / Evaluation of sites of terrestrial orchids in selected areas

HRUŠKOVÁ, Jana January 2010 (has links)
The point of that experiment was checking on status of selected areas with appearance of Dactylorhiza majalis and Dactylorhiza fuchsii around České Budějovice in south Bohemia. On 4 areas there were finding of biometric charakteristics always 40 selected plants and theirs mutual correlation in fact of more detailed knowing of status of individual population those kinds in particular area. There was always completed also phytocoenotic characteristics of the area. The graduation theses also includes updated information about few others tenths of areas of different kinds of orchids in České Budějovice and Český Krumlov area. Part of the experiment is map display of areas of the orchids. In map there are picture only areas with GPS not others.
7

Orchideje jako model studia ekofyziologických adaptací mykoheterotrofních rostlin / Orchids as a model for research in ecophysiological adaptations of mycoheterotropic plants

Ponert, Jan January 2018 (has links)
Perhaps all orchids are mycotrophic at early developmental stages, while majority of species photosynthesize at adulthood and only about 200 species remain fully mycotrophic for the whole life. Mycotrophy affects orchids at many levels. In this thesis, I focus on four aspects of orchid biology, which could be connected with mycotrophy: (i) systematics, (ii) genome size and endoreduplication, (iii) regulation of seed germination and (iv) mechanism of transfer of carbon and energy from fungi to orchids. There are over 27,000 recently recognized orchid species, nevertheless new ones are still discovering and old ones are revisiting. In this work I present a description of new species, Cleisostoma yersinii, and its morphological, anatomical, ecological and systematic characterization. Phylogeny reconstruction confirmed relationship with C. birmanicum. In the subtribe Podochileae, I reappraised the genus Campanulorchis to establish monophyletic but also morphologically defined group. For both abovementioned genera I prepared the artificial identification key. In the genus Dactylorhiza I revised taxa present in our country and I prepared an identification key which firstly mentions D. maculata subsp. elodes from Czech Republic. Orchid species diversity is probably reflected in genome structure. Results...
8

Orchideje jako model studia ekofyziologických adaptací mykoheterotrofních rostlin / Orchids as a model for research in ecophysiological adaptations of mycoheterotropic plants

Ponert, Jan January 2018 (has links)
Perhaps all orchids are mycotrophic at early developmental stages, while majority of species photosynthesize at adulthood and only about 200 species remain fully mycotrophic for the whole life. Mycotrophy affects orchids at many levels. In this thesis, I focus on four aspects of orchid biology, which could be connected with mycotrophy: (i) systematics, (ii) genome size and endoreduplication, (iii) regulation of seed germination and (iv) mechanism of transfer of carbon and energy from fungi to orchids. There are over 27,000 recently recognized orchid species, nevertheless new ones are still discovering and old ones are revisiting. In this work I present a description of new species, Cleisostoma yersinii, and its morphological, anatomical, ecological and systematic characterization. Phylogeny reconstruction confirmed relationship with C. birmanicum. In the subtribe Podochileae, I reappraised the genus Campanulorchis to establish monophyletic but also morphologically defined group. For both abovementioned genera I prepared the artificial identification key. In the genus Dactylorhiza I revised taxa present in our country and I prepared an identification key which firstly mentions D. maculata subsp. elodes from Czech Republic. Orchid species diversity is probably reflected in genome structure. Results...

Page generated in 0.1527 seconds