National Repository of Grey Literature 25 records found  beginprevious16 - 25  jump to record: Search took 0.01 seconds. 
Craniometric study of Central European populations of the white-toothed shrews Crocidura suaveolens and C. leucodon (Mammalia: Soricomorpha)
Milerová, Petra ; Vohralík, Vladimír (advisor) ; Anděra, Miloš (referee)
Interspecific and intraspecific size variability of the skull, mandibles and teeth of the lesser white- toothed shrew Crocidura suaveolens and the bicolored white-toothed shrew C. leucodon was studied on material of 350 skulls and 465 mandibles of white-toothed shrews obtained by analysis of the barn owl pellets originating from four regions in the Czech Republic and one region in the southern Slovakia. C. suaveolens was present in all regions under study, while sympatric C. leucodon occurred in three regions only. In total, 21cranial and dental measurements and 4 mandibular measurements were investigated. It was found that the most reliable measurement enabling discrimination between skulls of both species in the whole studied material is the lenght of the lower dental row. If skulls of both species were evaluated separately for each area of their sympatry it was possible to use also the distance between second molars M2 and the width of premolar P4 . Skulls of these two species can also be distinguished by bivariate graphs using the length and width of premolar P4 and the palatal length. We studied relationships between cranial measurements of both species and geoclimatic factors such as longitude, latitude, mean annual temperature and mean annual percipitation. It was found that variability of...
Different response of maize inbred and hybrid genotypes to drought: analysis of leaf proteome and photosynthetic processes
Benešová, Monika
Drought is one of the most important stress factors affecting plants. Increasing drought resistance via plant breeding is currently the main approach for improvement of plant productivity and reduction of water usage. Plant breeders and scientists search for reliable and easy methods of the determination of drought sensitivity in different genotypes. A precise knowledge about processes underlying plant stress response and defence against limited water availability is necessary for this. The aim of this study was a detailed analysis of photosynthetic processes and changes in leaf proteome (again aimed especially at proteins involved in photosynthesis) during drought stress. This analysis was a part of a complex project focused on the possible causes of genetic variability and drought resistance in agronomically important crops. Another goal was to analyse whether the measurement of selected photosynthetic parameters can be used for the determination of drought sensitivity per se and/or for the prediction of the response of hybrids based on known behaviour of their parents. Young plants of maize inbred lines and their hybrids were used as a model for this analysis, which was made under conditions of moderate and more severe drought. Two inbred lines which were (together with their F1 hybrids) used...
Different response of maize inbred and hybrid genotypes to drought: analysis of leaf proteome and photosynthetic processes
Benešová, Monika ; Holá, Dana (advisor) ; Prášil, Ilja (referee) ; Pospíšilová, Jana (referee)
Drought is one of the most important stress factors affecting plants. Increasing drought resistance via plant breeding is currently the main approach for improvement of plant productivity and reduction of water usage. Plant breeders and scientists search for reliable and easy methods of the determination of drought sensitivity in different genotypes. A precise knowledge about processes underlying plant stress response and defence against limited water availability is necessary for this. The aim of this study was a detailed analysis of photosynthetic processes and changes in leaf proteome (again aimed especially at proteins involved in photosynthesis) during drought stress. This analysis was a part of a complex project focused on the possible causes of genetic variability and drought resistance in agronomically important crops. Another goal was to analyse whether the measurement of selected photosynthetic parameters can be used for the determination of drought sensitivity per se and/or for the prediction of the response of hybrids based on known behaviour of their parents. Young plants of maize inbred lines and their hybrids were used as a model for this analysis, which was made under conditions of moderate and more severe drought. Two inbred lines which were (together with their F1 hybrids) used...
Inter-population variability of the bird song
Bílková, Jana ; Petrusková, Tereza (advisor) ; Musilová, Zuzana (referee)
Inter-population variability of the song is widespread phenomenon among birds. Populations of same species from different geographical areas might differ in vocalization. In case of dialects there are even no transitions between particular song forms, but clearly demarcated boundaries. Although the majority of studied cases concerns songbirds, it is possible to find examples in other orders as well. Studies showed that individuals inhabiting forests sing shorter and simpler songs with a lower frequency than their relatives from open landscapes. Changes in temporal and frequency characteristics can also be found in populations living in noisy cities. Different songs, however, are also produced by individuals from populations whose habitats do not show any significant differences. If these groups also differ genetically, then the different variants of song could be caused by heredity, especially in species with innate song. However, this variability may be the consequence instead of the cause of assortative mating, which might be the result of interpopulation variability in some cases. In species where the song is at least partially learned it is more likely that social interactions will play the key role - particularly if females prefer males singing local dialect or if sharing the song with neighbors...
Exploration, neophobia and dietary conservatism in tits (Paridae)
Beranová, Eliška ; Exnerová, Alice (advisor) ; Fučíková, Eva (referee)
Neophobia and exploratory behaviour are two processes applied in great measure in birds' reactions towards novel stimuli. The specific demonstration of these two processes may differ between different species of birds as well as within them. We compared neophobia and exploratory behaviour in two species of tits (Paridae). Adult Great tits (Parus major) and Blue tits (Cyanistes caeruleus) did not differ neither in exploring novel environment and novel object nor in neophobia towards novel object near food. We have found great differences between juveniles of these two species. Juvenile Blue tits were more neophobic towards both novel objects. Age, sex and personality affected some differences within tested species. We tested whether there exist any differences in reactions towards novel food between and within species. We used red painted mealworm (larvae of Tenebrio molitor), house cricket (Acheta domestica) and aposematic bug (Pyrrhocoris apterus) as novel food. Adult wild-caught tits with plentiful experience with various feeds did not differ in reaction towards these types of novel food. In contrast hand-reared juvenile tits differed quite a lot. Juvenile Blue tits were more neophobic than juvenile Great tits towards all three types of novel food. We found dieraty conservatism, phenomenon...
Intraspecific variability in plant antioxidant systems and its impact on drought tolerance
Jelénková, Iva ; Kočová, Marie (advisor) ; Zelenková, Sylva (referee)
Drought is one of the major factors limiting agricultural production. Reactive oxygen species (eg. superoxide radical, hydroxyl radical, hydrogen peroxide) generated during stress in plant cells activate antioxidant mechanisms, which scavenge those toxic substances. The positive correlation between activity of enzymatic (eg. catalase, superoxide dismutase, glutathione reductase, peroxidases) and nonenzymatic (eg. glutathione, ascorbic acid) antioxidants and stress tolerance was confirmed in various studies. Both interspecific and intraspecific variability was found in activities of antioxidant systems of plants. Higher activity was also observed in F1 generation in relation to positive heterosis, or in plants treated with supportive substances such as abscisic acid, brassinosteroids and nitrogen. The increase in the activity of antioxidants was also proved in relation to the ploidy level or to intensity of drought. It was observed the positive effect of previous drought exposition on tolerance to other abiotic stressors. The complex response of plants to stress factors depends on many other internal and external factors.
Inter- and intraspecific variability in Vicia faba L. and Zea mays L. response to water deficit
Fridrichová, Lenka ; Holá, Dana (advisor) ; Zelenková, Sylva (referee)
This work monitors the response of plants to water deficit and subsequent restoration of water availability with the aim to expand our knowledge about plant behaviour during and after drought stress from the perspective of two plant species with a different type of photosynthesis. A particular attention was paid to the intraspecific differences and their possible changes during stress and post-stress periods. The plant response was monitored as the changes of selected photosynthetic, morphological and developmental characteristics caused by the cessation of watering for six days followed by a six-day period of renewed optimal water supply. The experiments were carried out on plants with different types of photosynthesis - C3 plant Vicia faba L and C4 plant Zea mays L.; for both plant species, three varieties / genotypes were monitored. The response of both plant species to insufficient water supply differed by the extent of changes in relative water content (RWC), chlorophyll fluorescence parameters, the dry mass of individual leaves (developed during the stress period), the ratio between the aboveground dry mass and dry mass of roots. In drought-stressed plants, downward trend in RWC was observed, as well as the increase of the minimum yield of chlorophyll fluorescence in dark-adapted leaves (F ),...
Fylogeneze, diverzita, distribuce a hostitelská specifita parazitů Haemoproteus spp. (Apicomplexa: Haemosporida: Haemoproteidae) u suchozemských želv Palearktu.
MARŠÍKOVÁ, Aneta
This study provides unique data on distribution, prevalence, host specificity, phylogeny, and intraspecific variability of two Haemoproteus species of Palearctic tortoises. Analyses based on cytochrome b sequences confirm the existence of two monophyletic lineages/species of Haemoproteus infecting Testudo tortoises. Microscopically, the species corresponding to H. anatolicum was revealed in blood smears of T. graeca, and H. caucasica was detected in two tortoise species, T. graeca and T. horsfieldii.
Exploring the relationship between species richness and intraspecific trait variability.
DVOŘÁKOVÁ, Hana
This thesis was originated as a contribution to the wide range of biodiversity studies published recently. It focused on the little explored importance of intraspecific variability in plant communities. A pot experiment hold in glasshouse environment was designed to observe influence of biotic interactions in mixtures of various species diversity on species functional traits and productivity. Variability of functional traits of individual species was assessed in relation to increasing species richness and the contribution of within-species variance to the total variance of pot communities was evaluated at different richness levels.
Ecological comparison of three closely related species from \kur{Myosotis palustris} group
KOUTECKÁ, Eva
The study is focused on comparative ecology of three closely related species from Myosotis palustris group. Importance of various functional traits of individual species was evaluated experimentally in the greenhouse (germination experiments), in the pot experiment and in the reciprocal transplant field experiment. Germination, production of clonal structures and response to various environmental conditions (competition, moisture conditions, etc.) were studied. The experimental data are supplemented with an analysis of phytosociological relationships of the studied species.

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