Variation and taxonomic significance of some morphological features in European strains of Klebsormidium (Klebsormidiophyceae, Streptophyta)
Š kaloud, Pavel
Forty uni-algal strains of Klebsormidium Silva, Mattox & Blackwell (Klebsormidiophyceae, Streptophyta) were examined by light microscopy to test the stability of current discriminating features for the distinction of the narrowly related species Klebsormidium flaccidum (Kützing) Silva, Mattox & Blackwell and K. nitens (Meneghini in Kützing) Lokhorst. Cell dimensions, filament length, character of zoosporangia and zoospore germination were studied. The habit of cell morphology in relation to the culture age was studied in six randomly chosen strains. The effect of physico-chemical parameters (temperature, humidity, illumination and pH) on cell width was studied on two selected strains. Each strain was transferred to two extreme conditions of one physicochemical parameter, whereas the other parameters remained the same. The study showed variability in taxonomically relevant morphological features during growing of the species in cultures. For example, there are strong indications that the type of aperture in empty zoosporangial cell walls, considered as a species-specific character, is dependent on environmental factors, in particular on habitat humidity.In conclusion, it is possible to significantly divide the strains according to three attributes - cell width, character of zoosporangia and microbiotope of habitat. However, each character divides the strains into dissimilar groups. Therefore, it is impossible to decide which feature is the most suitable for proper differentiation of Klebsormidium nitens and K. flaccidum.