Germination of different gyrogonite types of Chara intermedia A. Braun 1836

The paper presents the germination of different types of gyrogonites of Chara intermedia A. Braun 1836. The study material was collected from the surface layer of sediments (sediment gyrogonites) and from dead C. intermedia specimens inhabiting a post-excavation pit. As a result of a low level of water and seasonal drying, two morphological types of gyrogonites taken from the thallus were distinguished: fully ripe gyrogonites and gyrogonites in oosporangium remains. The highest germination rate was recorded for the sediment gyrogonites. At the end of the experiment, about 28% of germinating gyrogonites originating from sediments were observed. The value of this parameter was over 3-fold higher than that of fully ripe gyrogonites produced by the thallus and more than 5-fold higher in relation to gyrogonites in the oosporangium remains. The results of this experiment indicate that the germination of the two morphological types of gyrogonites taken from plants depends on the degree of their maturity and can take place under limited light conditions. Drying of charophyte thallus in shallow water bodies may have a significant impact on the degree of maturity of gyrogonites, their morphological differentiation, and sediment seed bank characteristics.