National Repository of Grey Literature 10 records found  Search took 0.02 seconds. 
The relationship between genetic and ploidy variation in the context of differing ecological conditions of two species of the genus Pteronia (Asteraceae) in the Cape
Havlíčková, Eliška ; Chumová, Zuzana (advisor) ; Záveská, Eliška (referee)
The genus Pteronia is an example of a recently radiated and taxonomically complicated genus of the family Asteraceae (sunflower family) with endemic connection to southern Africa. Most of the species are associated with the Cape region, an area characterised by a Mediterranean type of climate, which is comparable in species richness to the flora of tropical areas, especially on smaller geographical scales. The factors behind the high diversity of the Cape are environmental heterogeneity, climatic stability (low extinction and accumulation of species) and regular disturbance by fire. Polyploidization, one of the main mechanisms of plant evolution, has been an overlooked and denied phenomenon in the Cape for a long time. Individual cases of polyploidy are being revealed, but the causes of their emergence and extent of their occurrence are unknown. The presented work focuses on polyploidization in the genus Pteronia from the perspective of two species with different ecological valence. On the widespread to invasive species Pteronia incana and, on the contrary, on the endemic species of succulent karoo and deserts, Pteronia glabrata. Using flow cytometry, genome size variation was investigated and ploidy levels determined. The obtained cytometric data were used to compare climatic, topographic,...
Causes of diversity in the Cape Floristic Region
Havlíčková, Eliška ; Chumová, Zuzana (advisor) ; Záveská, Eliška (referee)
The Cape Floristic Region (Capensis) is the smallest phytogeographical kingdom in the world with an area about 90,000 kmš (or 190,000 kmš if the succulent karoo is included). However, thanks to the subtropical climate influenced by the cold Benguel current and the isolated location behind the ridges of the Cape Mountains, it is characterized by an extremely diverse flora. There are about 11,000 species of plants, of which 79% are endemic. The Cape region shares many characteristics with other Mediterranean areas, but in many ways it is a unique environment. In this bachelor's thesis, the Cape flora is set in a global context and compared with other Mediterranean areas. Geological development, floristic and vegetation composition are described. The work also contains summarised information about the possible causes of high plant diversity and endemism of the Cape region. Keywords: Cape Floristic Region, Mediterranean, plant diversity, polyploidy, South Africa
Reconstructing the evolution and fylogenetic relationships of silica-scaled chrysophyte genus Mallomonas
Čertnerová, Dora ; Škaloud, Pavel (advisor) ; Záveská, Eliška (referee)
The taxonomic concept of the algal genus Mallomonas (Synurales, Synurophyceae) was based on an extraordinary morphological diversity of their siliceous scales. The main aims of this study were elucidation of phylogenetic relationships among its representatives and reconstruction of shape evolution of particular siliceous structures of their scales. Molecular data for six species were acquired for the first time, enabling a successful assessment of their phylogenetic relationships with the other representatives of the genus. On the basis of molecular data, the genus Mallomonas can be divided in two evolutionary lineages and this division is also reflected morphologically (with only a few exceptions) through presence or absence of a V-rib structure. Fine ornamentation of siliceous scales is species-specific and interestingly, the overall differences in morphology of siliceous scales are mostly reflecting phylogenetic relationships among representatives of the genus. In this context, morphological species concept of Mallomonas seems to be justified. Morphologically-based sections of the genus are often paraphyletic, because small sections (frequently containing only single species) tend to be nested within particular larger sections. The main reason for this discrepancy is accelerated morphological...
Systematics and phylogeography of diploid lineages of Arabidopsis arenosa complex
Hyklová, Lucie ; Záveská, Eliška (advisor) ; Krak, Karol (referee)
The Arabidopsis arenosa species complex is closely related to the model species Arabidopsis thaliana. Distribution range of the diploid lineage covers most parts of Central and South-eastern Europe with a remarkable diversity of ecological niches from sea level to alpine peaks. There is still little known about genetic relationships among the diploid populations of A. arenosa. The evolutionary history of the diploid cytotype across its entire range was explored by using 14 nuclear microsatellite loci. Five lineages occupying biogeographically distinct regions were identified in Arabidopsis arenosa complex. These lineages were labelled as Western Carpathians, Eastern Carpathians, Pannonian Lowland, Dinaric Alps and Baltic Shore (according to geographical regions where these lineages occur). Powered by TCPDF (www.tcpdf.org)
Phylogenetic Studies in the Polyploid Genus Curcuma L.
Záveská, Eliška ; Fér, Tomáš (advisor) ; Schmickl, Roswitha Elisabeth (referee) ; de Boer, Hugo (referee)
1 Phylogenetic Studies in the Polyploid Genus Curcuma L. SUMMARY Curcuma is genetically one of the most complex genera within the tropical family Zingiberaceae, with hybridization and polyploidization being the major forces in its evolution. In this thesis, I have focused mainly on the genetic background of Curcuma species variation, relationships and overall genome structure, as a key to solve long standing taxonomic problems. Results of my molecular studies on the genus Curcuma performed since 2007 represent an extension of ongoing taxonomic and nomenclatural work started by Jana Leong- Škorničková in 2000. The first part of the thesis consists of a broad, general introduction to the subject to reflect the current state of knowledge, formulate the major problems to be confronted within the genus, and summarise the major results of the studies presented in the second part of the thesis. As the main obstacles in studying Curcuma are consequences of its reticulate evolution, it is also outlines the importance of understanding the genetic background and species relationships using molecular markers. Common molecular methods used for assessing phylogenetic relationships on the intraspecific and infrageneric levels - AFLP and sequencing of selected markers from cpDNA, nrDNA and nDNA - are described, with the...
Biogeography of pantropical plant family Costaceae
Böhmová, Alžběta ; Fér, Tomáš (advisor) ; Záveská, Eliška (referee)
The aim of the thesis is to describe and to evaluate current knowledge about distribution and evolution of the plant family Costaceae. This plant family is characterized by pantropical spread. The centre of diversity is in South and Central America. At present, this plant family contains seven genera; some of them have been described recently based on new phylogenetic knowledge. The biggest genus is Costus, which turned out to be paraphyletic. It has pantropical spread and what is more, it forms 75 % of the family. Each of the remaining genera is associated with a certain continent and has only a very few members. The biogeographical history of this family has not been fully cleared up yet, but it seems to have gained the pantropical character owing to multiple-dispersion. Key words: Biogeography, Costaceae, pantropical distribution, phylogeny
Biogeografie zázvorovitých z podčeledi Alpinioideae
Hlavatá, Kristýna ; Fér, Tomáš (advisor) ; Záveská, Eliška (referee)
This work aims to summarise the recent knowledge of the distribution of the subfamily Alpinioideae and suggest the possible patterns of distribution and dispersal for individual genera, particularly for South-East Asia, where the majority of genera is found. Alpinioideae is a quite recently established and unresolved group and some of its genera are polyphyletic. The main part of the subfamily is distributed throughout South-East Asia to Australia and Oceania, two genera (Aframomum and Renealmia) are found in Africa and the genus Renealmia has undergone long-distance dispersal to South America. Three genera (Leptosolena, Paramomum and Siamanthus) are monotypic endemics. Alpinioideae is further divided into the tribes Alpinieae and Riedelieae.