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Synura echinulata (Synurales) - silica scale plasticity in natural populations influenced by environmental factors; accompanying scaled chrysophytes
Kreidlová, Jana ; Němcová, Yvonne (advisor) ; Hodač, Ladislav (referee)
The silica scale shape variation in Synura echinulata has been investigated only in laboratory conditions, so far. The aim of this thesis was to study scale shape variation in natural populations and to determine which environmental parameters influence the scale shape. The scale shape variation was investigated using landmark-based methods of geometric morphometrics. Scale shape changes related to environmental factors were analyzed using the two-block method PLS (Partial Least-Squares analysis) and adonis (R). The scale shape was mostly influenced by locality, pH and altitude. Shape distinguished populations of S. echinulata probably exist in different localities. The more distant localities are, the less similar are scales of S. echinulata in their shape. This scale shape variation is probably genetically determined, even thought all so far sequenced populations belong to the same species. High morphological disparity which was probably caused by anthropogenic pollution, was recorded in the locality Brdy. During sampling of the natural populations of Synura echinulata in the Czech Republic, several localities representing a significant reservoirs of species diversity, were found. Therefore, the thesis was extended and biodiversity research in the Czech Republic was added. A few samples were...
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Species concept in the genus Trentepohlia (Ulvophyceae, Chlorophyta): a combination of molecular and morphological approaches
Šafránková, Michala ; Škaloud, Pavel (advisor) ; Hodač, Ladislav (referee)
In this Master's thesis I engage in the problematics of the species concept of green subaerial alga Trentepohlia (Ulvophyceae, Chlorophyta). This genus has been studied intensively since the 18th century. For more than 200 years, Trentepohlia species have been delimited using various morphological criteria. However, recent molecular studies showed inadequacies in this approach Therefore, my goal was a precise morphological study of the European Trentepohlia species and the re-evaluation of their phylogenetic position using rbcL gene sequencing. During the period 2013-2015, I carried out a detailed study of the oldest references of Trentepohlia species and compiled a delimitation key of the European species. Based on this research I concluded that it would be desirable to synonymize T. odorata with T. jolithus, as well as T. uncinata with T. arborum. I also sampled Trentepohlia species within Europe and carefully studied and described their morphology. Fresh Trentepohlia thalli were molecularly characterized by cloning, which revealed a common mixture of Trentepohlia species in what on a first sight appears to be a homogenous crust. Phylogenetic analyses based on the rbcL confirmed the ongoing inconsistencies among morphologically and molecularly delimited species and also the existence of cryptic...
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Phylogenetic diversity of the genus Phyllosiphon (Trebouxiophyceae, Chlorophyta) in Europe
Procházková, Kateřina ; Neustupa, Jiří (advisor) ; Barcyte, Dovile (referee) ; Hodač, Ladislav (referee)
Abstact The trebouxiophycean genus Phyllosiphon includes unique and little known phototrophic green algae that form endophytic siphonous stages within the members of Araceae. In total, six parasitic species of the genus Phyllosiphon were originally described from the leaves of Araceae, but the only known DNA sequences were acquired from P. arisari, a species that infects leaves of Arisarum vulgare growing in the Mediterranean region. Surprisingly, the environmental sequences closely related to those obtained from P. arisari were recently detected in samples of phototrophic biofilms thriving on sandstone substrates in Germany and Northern Ireland. However, these studies did not provide any information about morphology of these microalgae. In this thesis, I was looking for Phyllosiphon parasites in the leaves of terrestrial members of the Araceae growing in the Mediterranean Europe in order to find out whether parasitic algae of the Phyllosiphon isolated from different taxa of the Araceae are phylogenetically differentiated, or they form a single lineage within the Watanabea clade of Trebouxiophyceae. In addition, corticolous biofilms from various localities in Europe were sampled in order to detect any presence of Phyllosiphon cells outside their hosts. Both the parasitic thalli and chlorelloid unicells of...
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Species concept in the genus Trentepohlia (Ulvophyceae, Chlorophyta): a combination of molecular and morphological approaches
Šafránková, Michala ; Škaloud, Pavel (advisor) ; Hodač, Ladislav (referee)
In this Master's thesis I engage in the problematics of the species concept of green subaerial alga Trentepohlia (Ulvophyceae, Chlorophyta). This genus has been studied intensively since the 18th century. For more than 200 years, Trentepohlia species have been delimited using various morphological criteria. However, recent molecular studies showed inadequacies in this approach Therefore, my goal was a precise morphological study of the European Trentepohlia species and the re-evaluation of their phylogenetic position using rbcL gene sequencing. During the period 2013-2015, I carried out a detailed study of the oldest references of Trentepohlia species and compiled a delimitation key of the European species. Based on this research I concluded that it would be desirable to synonymize T. odorata with T. jolithus, as well as T. uncinata with T. arborum. I also sampled Trentepohlia species within Europe and carefully studied and described their morphology. Fresh Trentepohlia thalli were molecularly characterized by cloning, which revealed a common mixture of Trentepohlia species in what on a first sight appears to be a homogenous crust. Phylogenetic analyses based on the rbcL confirmed the ongoing inconsistencies among morphologically and molecularly delimited species and also the existence of cryptic...
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Identification and ecophysiology of coccoid green algae dominating in ice-covered lakes on James Ross Island (NE Antarctic Peninsula)
Mihál, Martin ; Nedbalová, Linda (advisor) ; Hodač, Ladislav (referee)
The aim of this study was to assess the phylogenetic relationships, morphological and ecophysiological characteristics of three strains of coccoid green algae from Antarctica. The strains A and B are planktonic algae dominating in ice-covered lakes on James Ross Island (NE Antarctic Peninsula). The third strain (Ankistrodesmus antarcticus CCAP 202/25) was originally isolated from green ice from the Balleny Islands (Ross Dependency) and its description has been based only on morphological features. According to the phylogenetic analyses of 18S rDNA, ITS2 secondary structure and cell morphology, the strains A and B belong to one species of the genus Monoraphidium (Chlorophyta, Sphaeropleales, Selenastraceae) that should be described as new in the future. It is the first evidence that coccoid green algae are capable to become the dominant primary producer in the extreme environment of Antarctic lakes with extensive ice-cover. The strain CCAP 202/25 is closely related to Monoraphidium griffithii (type species of the genus Monoraphidium) suggesting its incorrect classification. All the strains were able to grow in a wide temperature gradient: 1-20 řC (A and B) and 1-30 řC (CCAP 202/25). Low light requirements reflected their original habitat. Together with relatively high growth rates and high content...
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Autotrophic microbial growths on needles of gymnospermous trees in relation to air pollution
Nováková, Radka ; Neustupa, Jiří (advisor) ; Hodač, Ladislav (referee)
Aero-terestric algae occure on a wide range of substrates, such as soil, plant, stone and rock surfaces and also on a variety of anthropogenic substrates. Morphological convergence towards coccoid or filamentous thalli, caused by frequent dessication stress, is typical for this group. Algae are frequently used for biomonitoring of various biotopes, mostly water biotopes, but also for bioindication of air quality. My diploma thesis is based on a study of autotrophic microbial growths on spruce and yew needles in relation to various air quality measures evaluating air pollution of sites. The results show that the occurence of microbial growths on needles is primarily influenced by the orientation towards cardinal points. However, the air pollution factors also proved to be significantly related to the quantitative measures of the microbial assemblages. Among them, the relative proportion of algae in microbial growths was the most tightly related to air pollution.
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An ecological perspective on diatom morphology.
Fialová, Markéta ; Kulichová, Jana (advisor) ; Hodač, Ladislav (referee)
A traditional species concept of diatoms is based on morphological characters of their siliceous boxes. A multidisciplinary approach to defining species of diatoms has revealed the hidden diversity within the traditionally defined species. But the newly recognized species are morphological variable and indistinguishable by the naked eye. Recent studies showed that different morphotypes show different ecological preferences. This master thesis focuses on the morphology of natural populations of the diatom species complex Frustulia rhomboides which contains both the traditional and the cryptic species, and it engages how the morphology reflects the effects of environmental conditions. Landmark methods of geometric morphometrics were used in order to analyze the morphological variability of diatom frustules of this species complex within various peat bog habitats in the Czech Republic. Selected environmental parameters were measured and the species composition of diatom communities present in the samples was investigated. These data were used to analyze the relationship between the environmental conditions and the cell shape variability within the complex. The analysis revealed the main trends of morphological variability related to different environmental conditions. Two morphotypes characteristic...
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Synura echinulata (Synurales) - silica scale plasticity in natural populations influenced by environmental factors; accompanying scaled chrysophytes
Kreidlová, Jana ; Němcová, Yvonne (advisor) ; Hodač, Ladislav (referee)
The silica scale shape variation in Synura echinulata has been investigated only in laboratory conditions, so far. The aim of this thesis was to study scale shape variation in natural populations and to determine which environmental parameters influence the scale shape. The scale shape variation was investigated using landmark-based methods of geometric morphometrics. Scale shape changes related to environmental factors were analyzed using the two-block method PLS (Partial Least-Squares analysis) and adonis (R). The scale shape was mostly influenced by locality, pH and altitude. Shape distinguished populations of S. echinulata probably exist in different localities. The more distant localities are, the less similar are scales of S. echinulata in their shape. This scale shape variation is probably genetically determined, even thought all so far sequenced populations belong to the same species. High morphological disparity which was probably caused by anthropogenic pollution, was recorded in the locality Brdy. During sampling of the natural populations of Synura echinulata in the Czech Republic, several localities representing a significant reservoirs of species diversity, were found. Therefore, the thesis was extended and biodiversity research in the Czech Republic was added. A few samples were...
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