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2005 - 2008 Přírodovědecká fakulta UK
Magisterská práce: Phylogenetic position of the genera Koliella, Raphidonema, Koliellopsis and Raphidemopsis (Trebouxiophyceae, Chlorophyta): aspect of ecophysiology in the cell shapes of nine selected strains. Školitel: Linda Nedbalová
Abstract: Using 18S rDNA sequence data, I reconstructed the phylogenetic position of members of the genus Koliella, Raphidonema, Koliellopsis and Raphidonemopsis within the frame of the class Trebouxiophyceae (Chlorophyta). Apart from lineages known up to now, I recognized a new lineage comprised of the species Koliella corcontica with closest relatives presumably among members of the order Trebouxiales. Furthermore, the results indicated basal position of members of the genus Raphidonema sensu str. (sensu HINDÁK) within the frame of clade comprised of „core“ species Koliella longiseta and Koliella sempervirens. On the contrary, members of traditional genus Koliellopsis and Raphidonemopsis did not demonstrate any phylogenetic divergence from other „core“ members of Koliella.
I measured ecophysiological characteristics of nine selected strains (rate of photosynthesis and growth rate under different combinations of photosynthetically active radiation and temperature), together with the surface/volume ratio of cells cultivated in media with different nutrient concentration. I found a positive correlation of growth rate and surface/volume ratio of the cells. Increase of the cellular surface/volume ratio did not show (with exceptions) any correlation with decreasing nutrient concentration. Possible connection between shifted surface/volume ratio and algal contamination of the Koliella spiculiformis CCALA 364 culture is also discussed.