National Repository of Grey Literature 50 records found  previous11 - 20nextend  jump to record: Search took 0.01 seconds. 
The efficiency of pollen transfer by selected functional groups of pollinators and the ability of plants to influence it
Freudenfeld, Martin ; Janovský, Zdeněk (advisor) ; Klečka, Jan (referee)
Pollinator functional groups differ in their pollen carryover effectiveness and in the importance for particular species of plants, due to specific functional traits of pollinator functional groups. Plant species differ in their specific functional traits too. I determined pollen loads of pollinators by swabbing their bodies with a jelly to compare pollen carryover effectiveness of pollinator functional groups. This helped me to decide which pollinator functional groups are the most and the least effective in pollen carryover. I considered an influence of the last visited flower to make the comparison of pollen loads more accurate. I also calculated proportions of conspecific and heterospecific pollen grains carried on bodies of pollinators to estimate their carryover effectiveness. Likewise, I compared composition of pollen morphotypes carried on pollinator's bodies to find out differences among pollinator functional groups. My analysis shows that pollen carryover effectiveness of particular pollinator functional groups differ. Apis mellifera and solitary bees have the biggest pollen loads, on the other hand, butterfies and small dipterans have the smallest pollen loads. The last visited flower influences an amount of pollen grains carried on bodies of pollinators. Relative pollen loads of some...
Measures to support populations of solitary bees in agroecosystems
Šlachta, Martin ; Erban, T. ; Votavová, A. ; Cudlín, Ondřej ; Cudlín, Pavel ; Halešová, T.
Solitary bees participate in the pollination of crops. According to our field\nsurvey, this involves 88 species of solitary bees in spring, mainly mining bees\n(Andrenidae) and sweat bees (Halictidae) nesting in the soil. The species\nnesting above soil were present less due to the lack of nesting opportunities\nand generally summer nesting activity. Among them, mason bees (Osmia sp.),\nnesting in spring, are used abroad for the pollination of fruit trees. The aim of\nthis methodology is to provide farmers with instructions for the use of mason\nbees for pollination of orchards by means of artificial nesting sites. We propose\na convenient construction of nesting sites and the methodology for rearing the\nEuropean orchard bee, Osmia cornuta (Latreille, 1805), which is, due to its earlyspring nesting activity, a suitable substitute for the currently used buff-tailed\nbumblebee. Breeding can be supplemented by the red mason bee, O. bicornis\n(Linnaeus, 1758), with later nesting activity. The book contains also suggested\nmeasures to support solitary bees in the landscape and new research data on\nthe diversity of solitary bees and pollen preferences of mason bees.
Influence of plant pollinator spectra generalization on plant reproductive success
Hanusová, Natálie ; Štenc, Jakub (advisor) ; Hadrava, Jiří (referee)
Plants are pollinated by variously wide pollinator spectra. Plants pollinated by a wide spectrum of pollinators are called generalized plants. There are many factors leading to the generalized strategy of plants including their morphology, environment context, local pollinator community, and competition between plants for effective pollinators. However, generalization is connected to potential risk because not all pollinators are equally efficient and effective. The Generalization of plants is a very flexible way how to deal with non-predictable conditions and achieve successful sexual reproduction. Further investigation is needed to understand how the generalization of plant-pollinator spectra shapes plants sexual reproduction. Keywords: pollinator spectra generalization, pollination, plants reproduction, plants reproductive success
Causes of limitation of plant reproduction by pollen and resource availability
Kalousková, Petra ; Janovský, Zdeněk (advisor) ; Sklenář, Petr (referee)
Plant seed production depends on many factors: their life history, the environment they grow in, and other factors such as biotic interactions. However, the immediate cause of the reduction in seed production is the lack of partners or the lack of resources available for seed production. This bachelor thesis aims to summarize and analyze the mechanisms of action and the relative importance of individual causes of limitation of plant seed production. Most plants are pollen limited at least in some seasons or in some localities, in the rest of the situations are plants resource limited. Pollen limitation can be quantitative (low pollen deposition) or qualitative (low quality of pollen). Existing theoretical models of pollen and resource limitation compare use of resources either to attract pollinators (increased flower size, increased number of rewards) and increase the chances of encountering them (change of phenology or prolongation of flowering) or to produce seeds. Plants can sometimes be seemingly pollen limited, with the pollen supplementation increasing seed production at the cost of reducing reproductive effort in the upcoming years. However, the most significant feature of pollination, which is often reflected in the alternation of reduced seed production due to insufficient pollen...
Reproductive success in orchid pollination
Steffelová, Michaela ; Kindlmann, Pavel (advisor) ; Janeček, Štěpán (referee)
The family Orchidaceae is very diverse; it is characterized by specialized strategies for attracting pollinators. Orchid species with deceptive flowers are special in that they do not produce nectar. This has advantages and disadvantages. The type of strategy determines the degree of reproductive success of orchids: sometimes positively, sometimes negatively. Although research on orchids has been going on for centuries, these plants are still not sufficiently studied. This bachelor thesis is written in the form of a literature research and examines the mechanisms that influence the reproductive success of orchids in relation to their pollination. The least studied phenomenon in this area is the relationship between floral display and orchid reproductive success. In most of the studies cited here, there is a linear positive relationship, but the results are far from being conclusive. Key words: Orchidaceae, pollination, reproductive success, floral display, rewarding species, deceptive species
Minor insect groups as pollinators and flower visitors
Jůna, František ; Kotyková Varadínová, Zuzana (advisor) ; Tropek, Robert (referee)
The aim of my bachelor thesis is to review flower-insect interactions in those insect orders which are traditionally recognized as minor groups of insect pollinators. This means Coleoptera, Diptera, Hymenoptera and Lepidoptera orders are excluded. The emphasis is on the occurrence of pollination relationship, but palynivory, nectarivory, flower herbivory and flowers as hunting-site are discussed too. Much of the research is just listing the species which were found on flowers without any deeper study of their relationship with the flower. These non-specified interactions are recognised as flower visitors. Most of this bachelor thesis is about the order of Thrips (Thysanoptera), because of the large number of pollinators in this order. On the other hand many other orders are only mentioned or they even are missing. There is little interaction by some orders, or the interactions are missing or they are unknown. Also fossil flower-insect interactions are mentioned too. Key words Pollination, Thrips, Cockroaches, Lacewings, True bugs, Scorpionflies, Earwigs, Orthoptera, Caddisflies
Pollinator movement and orientation at small spatial scales
Matoušková, Eva ; Janovský, Zdeněk (advisor) ; Tropek, Robert (referee)
Pollination is interesting andcomplex interaction between insects and plants which is essential for a wide spectrum of plants and animals. Hoverflies (Diptera: Syrphidae) and bees (Hymenoptera: Anthophila) are one of the most common pollinators in the Central Europe and are mostly involved in pollination of local plants. To maintain pollination, it is necessary the movement of pollinator from one flower of a specific species to another flower of the same species. This movement is affected by a number of factors based on both the environmental and pollinator traits. The aim of this work is to explore the nature of traits affecting pollinator flight between plants on small spatial scales, to classify the knowledge about the influence of pollinator and ambient effects to compare the differences between hoverflies and bees and suggest further possible fields of research. Keywords: pollination, hoverflies, bees, Syrphidae, Anthophila, movement
The Beekeepering in The Czech Republic on crossroads
Mohrová, Kateřina ; Bartoš, Michael (advisor) ; Daněk, Tomáš (referee)
The thesis entitled The Beekeeping in the Czech Republic on Crossroads aims to get in the current issues of beekeeping. It describes the field of beekeeping, one of the oldest human activities in terms of biology, ecology, history, sociology and practical use. The methodology of this thesis is set in the framework of qualitative research and the discipline of social and cultural ecology which is based on multidisciplinary research. During the research a questionnaire construction was used. The research part focuses on the social and generational issues of beekeeping and reveals the motivation of my respondents for keeping bees. Furthermore it interprets the opinion of my respondents on beekeeping organizations in the Czech Republic, their connection with nature and their own outlook for the near future of beekeeping. In the discussion I summarize the results of the interviews with my respondents and in the conclusion I re-evaluate the aimed goals of my thesis and I give suggestions for further research possibilities in this field.
Analysis of flower scents Clusia blattophila
Mitrovský, Ondřej ; Kalinová, Blanka (advisor) ; Vaníčková, Lucie (referee)
South American plant Clusia blattophila, growing on Nouraghes of French Guiana, produces relatively large amounts of volatile substances in the fragrance of its flowers. C. blattophila is dioecious plant with different flowering time of monosex flowers Male flowers bloom for one night, while female flowers bloom two nights. The volatiles were adsorbed to the adsorbent and washed out with hexane with internal standard. Analysis was performed by two-dimensional gas chromatography with mass spectrometric detection. The aim of my thesis was to determine the qualitative and quantitative characteristics of flower scents of both sexes. I also studied, whether there are differences in production of the major fragrance component, acetoin, during the first night of blooming. The flower fragrance is complex blend of volatiles. In total, 43 different chemicals were identified. Among them were monoterpenes (α-pinene, camphene, β-pinene, myrcene, limonene, (E)-β-ocimene, camphor) sesquiterpenes (α-copaene, β-caryophyllene, cis-α-bergamotene, trans-α-bergamotene, aromadendrene, (E,E)-α-farnesene, δ-cadinene), aldehydes (1-pentanal, 1-hexanal, 1-octanal, n-decanal), also four ketones (acetoin and its dimer, 2,5-hexanedione, 6-methylhept-5-en-2-one), alcohol butane-2,3-diol, carboxylic acid 2-methylpropanoic,...
The role of biotic interactions in population biology of meadow plants
Janovský, Zdeněk ; Herben, Tomáš (advisor) ; Lepš, Jan (referee) ; Ehrlen, Johan (referee)
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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