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Secondary Metabolits of Bryophytes
Štěpán, Michal ; Soldán, Zdeněk (advisor) ; Skýbová, Jana (referee)
The bryophytes are a very old group of plants that are credited with being the first to make the transition to land. To make this land transition possible, plants needed to develop strategies to combat various external environmental factors. And these means, to effectively combat the struggle on land, are various secondary metabolites. It goes without saying that the development of various protective mechanisms did not end there. In the conditions in which mosses live, they need to fight against various fungi and bacteria. In the fight against these organisms, they also use various secondary metabolites, of course. Moss secondary metabolites are a very interesting and understudied field. In this work, information regarding secondary metabolites of bryophytes and their analysis as well as the possible uses of isolated secondary metabolites are included. The beginnings of secondary metabolite research are covered, from one of the first terpenes isolated, which was marchantin in Marchantia polymorpha, to present-day studies focusing on the discovery of new secondary metabolites directly in selected representatives of bryophytes and, of course, their applicability in human activities. It has been confirmed from various international publications that bryophytes produce specific secondary metabolites...
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Biology of epiphytic bryophytes: methods of study
Reitschmiedová, Erika ; Soldán, Zdeněk (advisor) ; Novozámská, Eva (referee)
This thesis is aimed to provide basic description and summary of methods used to study biology/ecology of bryophytes, especially epiphytes. Described methods include study of mosses and liverworts; hornworts are not included due to the fact that their epiphytic form is not known. There are five chapters in this thesis, all of them are primarily focused on description of basic or most useful methods for studying phenology, growth, bioindication and environmental conditions, e.g. light and water relationship measurement as well as bark pH measurement. The last one, "Forms and Strategies", is only terminological and it includes terms of life and growth forms and life strategy which are used in studying colonies of bryophytes.
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Diversity of the genus Riccia (Marchantiophyta)
Spurná, Veronika ; Soldán, Zdeněk (advisor) ; Svoboda, David (referee)
The main aim of this thesis is to give a brief overview of the genus Riccia. It belongs to the same taxonomic group as the genus Ricciocarpos Corda, family Ricciaceae (order Marchantiales, department Marchantiophyta). Both genera have a simple endosporophile and they do not possess elaters. The genus Riccia has a wide ecological valency. The representatives of the genus, who are adapted to life in drier areas, are able to grow on bare, sunny, clay soil. Other species can be found on wet places with high water occurrence or even directly in the aquatic environment. The genus has a worldwide distribution. The most abundant diversity is in subtropical areas with high environment variety which directly influences the diversity of this species. Representatives of this genus are able to survive extreme conditions and can very easily adapt to new conditions. They are also defined by great morphology plasticity. There are still problems to correctly distinguish some species from each other beacause of this reason. There are 13 species in the Czech Republic, three of them are easily interchangeable. Part of the thesis is therefore focused on the comparison of the species R. fluitans and R. rhenana from the Ricciella section. The former is typically found on the surface of the water. However, when found...
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Biology of epiphytic bryophytes: methods of study
Reitschmiedová, Erika ; Soldán, Zdeněk (advisor) ; Novozámská, Eva (referee)
This thesis is aimed to provide basic description and summary of methods used to study biology/ecology of bryophytes, especially epiphytes. Described methods include study of mosses and liverworts; hornworts are not included due to the fact that their epiphytic form is not known. There are five chapters in this thesis, all of them are primarily focused on description of basic or most useful methods for studying phenology, growth, bioindication and environmental conditions, e.g. light and water relationship measurement as well as bark pH measurement. The last one, "Forms and Strategies", is only terminological and it includes terms of life and growth forms and life strategy which are used in studying colonies of bryophytes.
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(A)sexual Life of Liverworts
HOLÁ, Eva
This thesis comprises of two published papers and one accepted manuscript, focused on various aspects of liverwort reproduction. Treated aspects include patterns of asexual reproduction, sex ratio and sex-specic pattern in vegetative growth, and patterns of genetic variation and spatial genetic structure of populations differing in availability of substrate on localities and the population connectivity, and consequently in size, density, and prevailing reproductive mode. These characteristics were studied on representatives of the family Scapaniaceae s.l., belonging to the largest liverwort order Jungermanniales. The results showed that asexual propagules were formed and present in course of the whole growing season and can be considered as a sufficient substitution for sexual reproduction. In contrast with the female-biased sex ratio observed earlier in most dioicous bryophytes, unexpectedly high male-biased sex ratio was observed in the aquatic liverwort, which was speculated to represent a strategy to overcome sperm dilution in aquatic environment. In addition, no size differences between female and male shoots were detected, although the evidence for higher cost of sexual reproduction in females was found. The study of population genetic structure has shown that even small and predominantly asexually reproducing populations are important sources of genetic variation. However, we were able to demonstrate notably low levels of gene flow among populations where habitat fragmentation poses a significant barrier to dispersal of diaspores. The fine scale study of spatial genetic structure revealed a strong aggregation of genotypes, particularly in smaller populations, and at the same time showed that asexual reproduction is an efficient mean of maintaining the populations at not only the short distances, given the spatial extent of clones spanning dozens of meters.
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