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Chrysophyte stomatocysts - encystation and excystation dynamics - bentic resting stages of chrysophytes
Mušálková, Petra ; Němcová, Yvonne (advisor) ; Juráň, Josef (referee)
The resting resistant stage has several important roles for phytoplankton microorganisms. It protects them from hostile conditions, allows them to spread to new locations and is often part of their life cycle. Chrysophytes form large populations for only a short part of the year, and therefore the formation of a resting stage is key for them to re-establish a vegetative population the following year. Chrysophyte resting stages are called stomatocysts, which are silicified and have a unique species-specific morphology. They can be form after both sexual and asexual reproduction. This is an understudied area. Most described stomatocysts are not assigned to species and much is not known about the triggers of encystation and excystation. It is thought that a combination of external (temperature, light, nutrients) and internal (cell age and cell concentration) factors are involved. So far, only sexual encystation in Dinobryon cyindricum and Synura petersenii has been studied in detail. My diploma thesis is based on laboratory experiments with Ochromonas tuberculata, Synura uvella and two strains of Synura petersenii. The aim of the study was to investigating whether external conditions such as temperature and lack of nitrogen or phosphorus have the effect on asexual encystation and whether it is...
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Pilot study on the issue of Euglenophyta in the Czech Republic
JURÁŇ, Josef
On the basis of literature review and floristic survey of almost 150 localities a revised checklist and a proposal of redlist of the Euglenophytes of the Czech republic were made. 286 taxa are reported from our state from which 5 taxa are new for Czech republic - Lepocinclis caudata, Monomorphina reeuwykiana, Phacus arnoldii, Trachelomonas bituricensis var. lotharingia, Trachelomonas volvocina var. punctata. The proposed redlist contains 9 taxa which are threatened by small number of localities or settle biotopes threatened by human impact.
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Euglenophytes of the Czech Republic in view of South Bohemia and the Bohemian Forest
JURÁŇ, Josef
A list of photosynthetic euglenoids of the Czech Republic was made from works about algal flora of the Czech Republic and this list was confronted with similar works from the Slovak Republic, Poland, Romania, Ukraine and Slovenia. Following the literature about algae from South Bohemia and the Bohemian Forest a checklist of photosynthetic euglenoids from this area was compiled. Data from this list were completed by my samples from this area. There were found 2 taxons new for the Czech Republic and 3 taxons new for South Bohemia and the Bohemia Forest.
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