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Overview of phylogeny, systematics and diversity of genus Ulva (Ulvophyceae) and biotechnological use of these algae
Kantnerová, Veronika ; Neustupa, Jiří (advisor) ; Němcová, Yvonne (referee)
The genus Ulva represents a remarkable group of organisms, with number of species. It belongs to the class Ulvophyceae, one of the major groups of chlorophytic green algae and it is characterized by a typical dual morphology and isomorphic haplo-diplontic life cycle. This work is a summary of existing knowledge related to this algal genus with regard to the phylogeny, diversity and ecology, which is relatively interesting due to the ability of these algae to adapt to a wide range of abiotic conditions. It also focuses on the development of thallus morphology of these algae, especially with relation to an interesting and very important role of symbiotic bacteria in this process and, last but not least, on the biotechnological utilization that has great potential for the future, especially in terms of the utilization of Ulva as an alternative renewable energy source, a food supplement with high content of important proteins, minerals and vitamins, or as a source of polysaccharides, the so-called "ulvans", which are now investigated for their biological activity and application in human medicine. Key words: Ulva, Ulvophyceae, phylogeny, morphogenesis, biotechnology, ekology, diversity
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Molecular phylogeny and taxonomic revision of chaetophoralean algae (Chlorophyta)
CAISOVÁ, Lenka
Since the human inclination to estimate and trace natural diversity, usable species definitions as well as taxonomical systems are required. As a consequence, the first proposed classification schemes assigned the filamentous and parenchymatous taxa to the green algal order Chaetophorales sensu Wille. The introduction of ultrastructural and molecular methods provided novel insight into algal evolution and generated taxonomic revisions based on phylogenetic inference. However, until now, the number of molecular phylogenetic studies focusing on the Chaetophorales s.s. is surprisingly low. To enhance knowledge about phylogenetic relationships among taxa within the order, the nuclear?encoded SSU rDNA sequences from 30 strains covering all three chaetophoralean families have been investigated. All revealed monophyletic groupings were further screened for molecular non-homoplasious synapomorphies within the Viridiplantae. To address the question of the correspondence between morphological characters traditionally used for taxonomical delimitation of the Chaetophorales and the tree topology favored by molecular data, the list of morphological/ ultrastructural/ecological characters was elaborated and further analyzed. In addition, to obtain a close-up view into the evolution of Compensatory Base Changes (CBCs) of the second internal transcribed spacer (ITS2) which is currently often used to delimit putative biological species, 86 newly obtained/published sequences of ITS2 for five families of the order Ulvales were analyzed. Furthermore, a detailed comparative study of all ITS2 substitutions has been done. Subsequently all revealed CBCs and hemi- CBCs have been mapped upon the ITS2 phylogenetic tree topology. Finally, CBCs/hCBCs taxonomic inference in the Ulvales has been discussed.
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