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Relationship between the genome size of mycobiont and ecological strategy of lichens
Konečná, Eliška ; Malíček, Jiří (advisor) ; Vondrák, Jan (referee)
The inner organisation of organisms originates from the information contained within its DNA. In addition, the size of the genome itself may influence the function of the organism. Unlike many other groups of organisms, genome size is only known for a very limited number of lichen mycobionts. So far it has been only speculated whether there is a connection between genome size, the ecology and the traits of lichens. The goal of my thesis is to measure genome size of a sufficient amount of lichen mycobionts to be able to determine possible connection between genome size and ecology or functional traits of these lichen species. I succesfully measured the genome size of 50 lichen species using flow cytometry (FCM). I did molecular phylogenetic analysis of 141 taxa with known genome size in order to recognize the influence of phylogeny on genome size of these species. Two genes - ITS and mtSSU - were used for the phylogenetic analysis. Statistical analysis was performed using measured genome sizes, ecologicaly relevant traits of lichen species and my phylogenetic tree. I found that genome size might be connected to substrate preference, vegetative reproduction or the type of the lichens' photobiont. A correlation of genome size and life strategy - larger genome sizes connected to K-strategy, whereas smaller...
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Diversity and phylogeny of symbiotic partners in zeorin-containing red-fruited Cladonia species.
Steinová, Jana ; Škaloud, Pavel (advisor) ; Pérez-Ortega, Sergio (referee) ; Vondrák, Jan (referee)
Lichens are a classic example of mutualistic symbiotic associations, yet the views on lichen symbiosis have changed considerably during the last fifty years. Nowadays, lichens are generally understood to be microecosystems consisting of several symbiotic partners which contribute in different ways to the prosperity of the whole system and which differ by the strength of their bond to other symbiotic partners. The level of knowledge of the individual partners (mycobionts vs. photobionts vs. bacteria) varies greatly in terms of their specificity, diversity and in the forces that shape this diversity. The main aim of this work was to reveal the diversity of organisms participating in lichen symbiosis and to better understand the biological forces which shape this diversity. We worked with a relatively common lichen group, zeorin-containing red-fruited Cladonia species, and specifically, we focused on the mycobionts, photobionts and bacteria that participate in this association. During the course of the study, it became apparent that species delimitation, which is a fundamental requirement for accurate diversity estimates, is another topic that requires further research. Our analyses revealed that species circumscription of most of recently recognized Cladonia mycobionts cannot by supported by...
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Dynamics of a lichen symbiosis
Vaiglová, Zuzana ; Škaloud, Pavel (advisor) ; Vondrák, Jan (referee)
The symbiotic relationships often represent not only the permanent cohabitation of two organisms, but they can evolve and change over time. Many papers published so far focused on the the specificity of lichens, characterising both highly specific species and those that can establish a symbiosis with many algal genotypes. In this second case we can imagine the possibility of a photobiont exchange during the life of lichen - the dynamics of lichen symbiosis. In this thesis I compared the occurence and diversity of photobionts within the thalli of lichens growing on the disturbed localities and on the the localities without the disturbance. These two types of localities were similar to species richness of photobionts, but the disturbed localities dominated by the number of photobiont genera. These localities also reached a higher value of phylogenetic diversity. Conversely, non-phylogenetic analysis revealed the higher level of photobiont diversity on non-disturbed localities, where the core of diversity was formed by different lineages of Trebouxia. I have also found the lichens, which cooperate with different algae on disturbed and non-disturbed localities. The photobiont distribution presented in this paper shows the possibility of photobiont exchange during the community succesion. The...
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Mythology of Reflex magazine cover pages
Vondrák, Jan ; Jirák, Jan (advisor) ; Šoltys, Otakar (referee)
This diploma work examines a product from the field of print media - front pages of magazine Reflex. Method of mythological analysis is used, which has been in qualitative research of media content applied for half of a century and is considered to be one of the traditional methods used by media studies. Unlike other dissertations in this thematic area this work does not only analyze visual or lexical contents of cover pages, but also focuses on participation of those contents in the development of myth. The work begins with introduction of key theoretical background and resulting terms used in following analyzes describing effects of myths in individual covers. Then the summary brings the interpretation and explanation of described phenomena. The work focuses to decipher myths contained in the first message which the Reflex magazine week after week addresses to his readers -the title page of individual issues. It analyses how the magazine constructs a system of myths, by which ideology can impact on its readers. Aim of this dissertation is not only to describe the process by which the myths capture a variety of signs and fill them with their own meanings, but also a dialectical relationship between myths and stereotypes or ideologies which stand in their background.
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Mollusc grazing and secondary metabolites of lichens
Černajová, Ivana ; Svoboda, David (advisor) ; Vondrák, Jan (referee)
In contrast to the much that is known about herbivory and its consequences, lichenovory has seldom been studied. Recently, studies confirming the anti-feedant role of lichen secondary metabolites were brought out and hypotheses considering the nature of these interactions were introduced. Also, a few papers dealing with the ecological consequences of lichenovory were published lately. My thesis was aimed on the secondary metabolites issue and the preferences of the lichen feeders in the natural conditions. Six epiphytic lichen species containing secondary compounds (Parmelia sulcata, P. saxatilis, Parmelina tiliacea, Melanelixia glabratula, M. subaurifera, M. glabra), two without them (Melanohalea exasperata, M. exasperatula) and two species of gastropods that naturally climb the trees to feed on lichens (Lehmannia marginata, Cochlodina cerata) were selected for grazing experiments. The deterring role of the lichen compounds was proven. These were also identified using thin-layer chromatography. Subsequently, a transplantation experiment was carried out. It was focused on specifying the preferences of lichen grazers in their natural habitat. The genus Melanohalea that does not contain any secondary metabolites was strongly prefered. No significant preferences among the other species used in the...
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Biogeography and specificity of Asterochloris photobionts
Řídká, Tereza ; Škaloud, Pavel (advisor) ; Vondrák, Jan (referee)
This diploma thesis has focused on the diversity and biogeography of Asterochloris photobionts. Since no study so far has been published on the biogeography of symbiotic microorganisms, the presented thesis is the first attemp to trace the biogeographic distribution and endemism of symbionts. By gathering 121 Asterochloris sequences obtained from lichen thalli sampled outside Europe and America, the diversity within the genus increased dramatically. The phylogenetic analysis based on the concatenated alignment of ITS rDNA and actin sequences obtained from Cladonia and Stereocaulon photobionts revealed 28 differently supported clades. Of them, eight lineages were newly discovered. Three environmental factors explaining the best the distribution pattern of Asterochloris photobionts were selected according to the statistical tests of the phylogenetic signal: two different types of biogeographical ecoregions and the substrate type. In general, the genus Asterochloris is distributed cosmopolitally, with a very low rate of endemism. Newly obtained data indicate that the restricted distribution of any photobiont clade is not caused by either historic or biological factors, but more likely by specific climatic or habitat preferences.
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Epiphytic species of Lecanora subfusca group in the Czech Republic
Malíček, Jiří ; Vondrák, Jan (referee) ; Palice, Zdeněk (advisor)
The main aim of this bachelor work is to summarize knowledges on species of the Lecanora subfusca group growing in the Czech Republic, eventually taxa their occurence may be expected in our area. Only epiphytic and/or epixylic species are included in this study because of a large diversity of the group. Ten taxa have been published from the country. This group is poorly explored in Central Europe because of difficult determination of single species. A comprehensive treatment is lacking in this area. For most taxa of this group only limited information on ecology, distribution, chemistry and taxonomic concepts exists. The present work is reviewing up-to-date knowledge of this group. Historical sources were based mainly on morphological and anatomical data. These were evaluated and excerpted. The bachelor work should serve as a basement for the following diploma thesis.
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