Phenotype diversity of the heterocytous cyanoprokaryotic genus Anabaenopsis

Jiří Komárek

Czech Phycology 5: 1-35, 2005  

Taxonomic review of the filamentous, nostocacean, heterocytous cyanobacterial genus Anabaenopsis (WOŁOSZYŃSKA) MILLER 1923 is presented in the article, with respect to diversity of natural populations. The specific development of heterocytes is the main traditional generic character of Anabaenopsis. This genus is delimited by both phenotypic and molecular criteria according to the modern cyanobacterial classification, but the infrageneric diversity is problematic. Morphological characters are discussed and the ecological data are included. A list of Anabaenopsis-taxa from natural habitats with their basic characters should serve as a background...

New trends in the megasystems of Eukaryote (Review)

Tomáš Kalina

Czech Phycology 5: 37-42, 2005  

Cyanobacteria of the West Carpathian Mts spring fens: single samplings

Petr Hašler, Aloisie Poulíčková

Czech Phycology 5: 43-55, 2005  

The presented study focuses on the cyanobacterial diversity and variability in the West Carpathian Mts spring fens. Samples were collected at 32 sites on the border between the Czech and Slovak Republics. Moss assemblages inhabited particulary by subaerophytic cyanobacteria and diatoms dominated the investigated spring fens. Cyanobacteria were isolated from fresh moss samples and identified using light microscope. Environmental variables were measured using mobile instruments (WTW Company) and statistic software Canoco (TER BRAAK & ŠMILAUER, 1998) was applied for data evaluation. Altogether 51 cyanobacterial species were identified, including several...

Comparison of the algal flora in subalpine and montane mires in the Krkonoše Mts (the Giant Mts; Czech Republic)

Sylvie Nováková

Czech Phycology 5: 57-68, 2005  

The subalpine mires in the Krkonoše Mts are unique among the Central European mountain mires due to their microtopography and phytosociology. The research was carried out to find out whether there is a difference between the subalpine and montane peatbogs in the algal flora as well. Samples from two subalpine mires (Pančavské rašeliniště, Úpské rašeliniště) and one montane bog (Černohorské rašeliniště) were examined. The algal flora of Pančavské rašeliniště peatbog diverged from the other two mires more than they differed each other. Local environmental conditions (e.g. physical and chemical variables, diversity of microbiotopes) seem to be more directive...

The first record of snow algae vitality in situ by variable fluorescence of chlorophyll

Jana Kvíderová, Marek Stibal, Linda Nedbalová, Klára Kaštovská

Czech Phycology 5: 69-77, 2005  

Although snow algae may serve as very good model organisms for their adaptation to extreme environments, ecophysiological studies of them are rare. In our study, we measured the dependency of relative electron transfer rate on the irradiance of natural samples by variable fluorescence of chlorophyll directly in the field. The sample consisted mainly of zygospores of Chloromonas brevispina (FRITSCH) HOH. ROEM. et MULL. The cell density in the snowfield (10⁵ cells.ml^-1) exceeded the lower detection limit of the fluorometer. The parameters of the dependency indicate the viability of zygospores. The values of maximum quantum...

Cytotoxic effect of soil cyanobacterial extracts to mammal cell lines YAC-1 and WEHI

Pavel Hrouzek, Jiří Kopecký, Jíří Salát, Blahoslav Maršálek, Alena Lukešová

Czech Phycology 5: 79-90, 2005  

The cytotoxic effects of ten methanol extracts obtained from soil filamentous cyanobacteria (Anabaena, Calothrix, Nodularia, Cylindrospermum, Tolypothrix and Trichormus) were studied. Two different mammal cell lines (YAC-1, WEHI) were selected for cytotoxicity testing using the MTT test and flow-cytometry (FC). For comparison, the brine shrimp assay (using Artemia as a testing organism) was performed. The composition of extracts was studied using HPLC-MS. Both MTT and FC found the cytotoxic effect in 6 of 10 tested cyanobacterial extracts, but these results did not correlate with those obtained by brine shrimp...

Chromium influences growth and cell morphology but itself does not induce gametogenesis in three Scenedesmus obliquus strains

Pavel Přibyl, Vladislav Cepák

Czech Phycology 5: 91-100, 2005  

Three Scenedesmus obliquus strains (LHOTSKÝ,O. 1966/7, PRINGSHEIM/Praha Ac. A 125 and TOMASELLI/Praha Ac. A 835) were treated with hexavalent Cr(VI) or trivalent Cr(III) chromium of various concentrations. Growth and morphological changes were investigated, focusing on possibly zoospores or gametes production. Compound of Cr(VI+) was found as the more toxic than Cr(III). Generally, Cr(VI) influenced relatively more growth processes whereas Cr(III) reproductive ones (cellular division). Individual strains differed in relative sensitivity to chromium variants. Strain TOMASELLI was more sensitive to Cr(III) and more resistant to Cr(VI) than the...

Algal growth regulators [in Czech]

Darina Dřímalová

Czech Phycology 5: 101-112, 2005  

The form and function of plants would not be possible without efficient regulation and coordination of metabolism, growth and morphogenesis. The occurrence of plant growth regulators in the algae has been the subject of several studies. Hormones have been detected in extracts of both unicellular and multicellular forms of algae. At first with the assistance of bioassays and more recently the use of high-performance liquid chromatography-mass spectrometry brought great progress in our understanding of phytohormone in algae. The synthesis and metabolism of plant growth regulators and the physiological responses of algae to these compounds has also been...