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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

Optimization and application of in vitro techniques in selected members of the family Brassicaceae

Hilgert-Delgado, Alois Antonín January 2016 (has links)
This thesis is focused on the application and optimization of biotechnological methods within the family Brassicaceae. Most of this thesis is focused specifically the genus Brassica. The main objective of this dissertation thesis was to optimize and apply selected biotechnological methods in the resynthesis of oilseed rape (B. napus) from its baseline species (B. oleracea, CC and B. rapa, AA) and subsequently create valuable genetic plant materials. The optimized procedure implemented in my work have exhibited better results of hybrid production (resynthesis) than in similar published experiments and provides a simplified and less laborious method via simple ovule culture and early hybrid verification. The next accomplished step was to work with a wider range of materials using a broader source of different and contrasting genotypes from Brassica rapa (spring and winter oilseed and vegetable turnips) and B. oleracea (green and purple curly kales and cabbages) for new combinations and wider genetic diversity. It was concluded that the optimized ovule culture protocol with early verification, developed in the framework of this thesis, is satisfactorily sufficient enough to be applicable in breeding programmes, aimed at diversity expansion of winter oilseed rape gene pool, as the resynthesized embryos were derived in most combinations. New resynthesized verified lines were colchicine treated in order to obtain diploid regenerants and the fertile plants were self-pollinized and crossed with elite oilseed rape lines for further research and breeding.
2

Endemický taxon Krkonoš Campanula bohemica: zhodnocení rizika hybridizace s C. rotundifolia / Risk assessment of interspecific hybridization between endemic Campanula bohemica and widespread C. rotundifolia s.l.

Hanušová, Kateřina January 2014 (has links)
The thesis deals with phenotypic, ploidy and genetic variation of two Campanula species occurring in the Krkonoše Mts., namely the endemic C. bohemica and widespread C. rotundifolia subsp. rotundifolia. For comparative purposes subspecies sudetica of the latter species was also included. The main aim was to get insight into population structure and assess the threat of interspecific hybridization to the survival of the endemic bluebell. Flow cytometry, distance-based morphometrics and molecular analysis were used to address these questions. Three distinct groups of fluorescence intensities were revealed by flow cytometry, corresponding to DNA diploids, tetraploids and pentaploids. While diploids morphologically matched the nominate subspecies of C. rotundifolia, tetraploids corresponded either to C. rotundifolia subsp. sudetica or C. bohemica. Most populations from the Krkonoše Mts. were uniform although a sympatric growth of diploids and tetraploids was encountered in 12 populations. Only two pentaploids individuals, most likely of hybrid origin, were found, which indicated that interspecific hybridization is much less common than previously assumed. The two tetraploid taxa were distinguished by molecular markers. A combination of flow cytometry and molecular analyses thus allowed reliable...
3

Detailní taxonomická a klonální struktura druhového komplexu Daphnia longispina na podélném gradientu přehradní nádrže Želivka / Detailed taxonomic and clonal structure of the Daphnia longispina species complex on the longitudinal gradient of the Želivka Reservoir

Stodola, Jakub January 2013 (has links)
Canyon shaped reservoirs are characteristic by specific environmental horizontal gradients, so they enable existence of several species of the Daphnia longispina complex in one water body. Due to preference of distinct environmental conditions Daphnia species occurre in the different localities. The aim of my thesis was to analyze detail taxonomical and clonal structure of Daphnia longispina group by ten microsatellite markers on longitudinal gradient and compare it between two consecutive seasons. Simultaneously I received newly discovered divergent mitochondrial lineage from Želivka reservoir. It was confirmed, that the distribution of species and their hybrids in water reservoir was non-concidental and the taxonomic spatial distribution is in two consecutive seasons relatively constant. On the contrary the spatial and temporal distribution of clones was very heterogeneous. Clonal diversity in the interspecific hybrids was lower than in the coexisting parental species. This finding supports the hypothesis, that there exist reproductive barriers between parental genomes. Most of the clones were substantively variable, but several clones that occurred in both seasons in similar localities were found. It is possible that some clones are able of overwintering in hypolimnion and in the spring...
4

Využití molekulárních markerů pro studium genetické diverzity u vybraných zástupců Dracaena

Ostrá, Zuzana January 2014 (has links)
Variability in the genetic information DNA tracking individuals carry is easy to detect using molecular markers. In the thesis we examined related Dracaena species. For the study of genetic diversity in the genus Dracaena are used mainly noncoding regions of cpDNA, spacer trnH -- psbA, regions trnL -- trnF and trnS -- trnG -- trnG, which are more variable than coding regions. Also used in this work were coding regions of matK and rbcL. In the genus Dracaena belongs xerophytic species that are characterized by typical shaped treetop. 14 representatives of species were used in thesis growing in tropical regions of the African continent and adjacent islands and the southeastern part of the Arabian peninsula. They are monocotyledonous trees with atypical abilities of secondary thickness of trunk, which I find interesting. The massive trunk is very strong and there is potencial to used it for wood. Trees are very significant for their red plant sap which flowing from demaged trunk. The sap is very precious resource which is used in many areas of industry, for example pharmacy, traditional medicine, dye making etc. Determination of genetic affinity was based on an amplification of cpDNA template of individual Dracaena samples with primers for the studied regions. Data was obtained and evaluated by Multiple alignment program ClustalX and BioEdit after their sequencing. Evalueted data was used to create dendograms affinity. According the resulting phylogenetic tree we find out similarities and identified relationship of the monitored species of the genus Dracaena. The main purpose of research was to get answers to understand phylogenetic relationship between group of Dracaena forestry used trees. The thesis was made in cooperation of Department of Forest Botany, Dendrology and Geobiocoenology, Faculty of Forestry and Wood Technology of Mendel University in Brno.
5

Nekrofágie u entomopatogenních hlístic

ČÁPOVÁ, Diana January 2017 (has links)
The aim of the present study was to study the occurrence of scavenging behavior among different species and strains of entomopathogenic nematodes. Another part of the study was focused on scavenging of the selected entomopathogenic nematodes in insects killed by various non-native strains of Xenorhabdus bovinenii. Further aim was to investigate the interspecific competition of the selected entomopathogenic nematodes with the nematode Oscheius myriophila for dead hosts. The final aim was the search for possible toxicity of the selected X. bovienii strains against nematode Oscheius myriophila.
6

Historické změny v druhovém složení a mezidruhová hybridizace perlooček druhového komplexu Daphnia longispina v Lago Maggiore / Historical changes in species composition and interspecific hybridization of the Daphnia longispina species complex (Crustacea: Cladocera) in Lago Maggiore

Faktorová, Zuzana January 2018 (has links)
Hybridizing species of the Daphnia longispina complex are key taxa in plankton communities of many European lakes. In several of these lakes, it has been documented that the taxonomic structure of the complex during the 20th century has substantially changed following human-mediated environmental changes, particularly eutrophication and re-oligotrophication and fish stock changes. We characterize these changes in Lago Maggiore (Italy/Switzerland), a southern pre-alpine lake, which also passed through the human-mediated environmental changes. Lago Maggiore is one of best and longest studied European lakes so a large number of historical Daphnia samples from regular monitoring are available. Because local Daphnia do not form dormant egg banks suitable for genetic analysis (being able to overwinter in the water column), we used a combination of morphology and geometric morphometrics (elliptic Fourier analysis) to evaluate the taxonomic and phenotypic changes in the Daphnia longispina complex in Lago Maggiore since the mid-20th century (1948-2012), and attampted to characterize the impact of environmental changes over the respective period on Daphnia body shape and size. Examination of Daphnia phenotype indicates indeed the prevailing presence of D. longispina (hyalina morph) in the 1940s, dominance of...
7

Mezidruhová agresivita lindušky luční (\kur{Anthus pratensis}) a bramborníčka hnědého (\kur{Saxicola rubetra}) / Interspecific aggression in meadow pipit (\kur{Anthus pratensis}) and whinchat (\kur{Saxicola rubetra})

LINHART, Pavel January 2007 (has links)
Interspecific aggression of meadow pipit (Anthus pratensis) towards treepipit (A. trivialis), whinchat (Saxicola rubetra) and skylark (Alauda arvensis) and interspecific aggression of whinchat towards meadow pipit was tested in playback experiments at the beginning of breeding cycle (both species) and during the brood feeding period (whinchat only). Neither meadow pipits nor whinchats responded aggressively to the playback of the heterospecific songs. Whinchats, however, chased or attacked meadow pipits that approached it in response to the meadow pipit songs in the brood feeding period. I suggest that the aggressive behaviour in whinchat is triggered rather by visual than acoustic cues. Another series of playback experiments with meadow pipits was carried out to investigate the effect of the sensitisation caused by previous playback of the conspecific song on performance during the playback of the tree pipit song 30 minutes later. No clear effect was discovered, but some of meadow pipits reacted in a way more characteristic for the intraspecific experiments.
8

Mezidruhová kompetice a hostitelské spektrum entomopatogenních hlístovek (Steinernematidae, Nematoda) / Interspecific competition and host range of entomopathogenic nematodes (Steinernematidae, Nematoda)

PŮŽA, Vladimír January 2009 (has links)
The presented thesis deals with interspecific competition and host range of entomopathogenic nematodes and assess the mechanisms enabling coexistence of multiple EPN species. The thesis further studied the scavenging ability of EPNs and their defense mechanisms against invertebrate scavengers. The results revealed that coexisting EPN species share the same niche and their interaction are complex and may be asymmetric. EPNs were found to be able to colonise and multiply in cadavers of different insects and scavenging seems to be an important alternative to normal infection. The defence of EPNs against scavengers seems to be an adaptation of the nematode-bacteria complex.
9

Analýza mitochondriálních genů živočichů pro DNA barcoding / Analysis of animal mitochondrial genes for DNA barcoding

Brabencová, Klára January 2014 (has links)
The aim of this work is a literature review on the topic of the mitochondrial genome and DNA barcoding, building a dataset of mitochondrial sequences from GenBank database and creatione of a software function for extraction of individual genes that are present in the mitochondrial genome. This function was developed in Matlab. DNA barcoding is a method that uses short DNA sequence of mitochondrial genome for identification of species. There is no comprehensive work examining the appropriateness of different mitochondrial genes. This aim investigates the potential of other mitochondrial genes and evaluate their effectiveness for DNA barcoding and calculation of intra-and interspecific variability.
10

Referenční význam slov při komunikaci člověka a psa / Reference meaning of words in human-dog communication

Stemmerová, Lucia January 2018 (has links)
In recent twenty years dogs have become model subjects of comparing studies. These experiments show us that specific cognitive skills have developed during their domestication as an adaptation to anthropomorphic environment. For example dogs can follow human gaze and understand gestures. An important topic of today researches are linguistic skills of dogs. Knowledge from this area would help to discover more from evolution processes which formed human language. Last studies have proven dogs can distinguish a new object by a fast mapping. But when distinguishing two new objects, dogs had problems. That is why I decided to verify if dogs are able to remember two new words and match them with correct objects during one session. For this experiment I worked on a new methodical procedure and used three border collies dogs. The results showed that after some training dogs were able to correctly distinguish two new words in case the experimentalist stood in front of them and they used multisenzorial perception. In case they had only one communication source (visual or acoustic), they made more mistakes. The results show that functional reactions of dogs to human vocalization are getting better if they can use visual and acoustic source in one time during an interspecies communication. Key words: dog,...

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