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Optimalizace procesu triploidizace u candáta obecného (Sander lucioperca)
TRNKA, Kamil
This thesis was aimed on optimization of induction of triploidization of pikeperch (Sander lucioperca) using cold, hot and pressure shocks. To induce the triploid status of the larvae using cold shock fertilized eggs of pikeperch were dropped into the cold bath of temperature 0,5-1°C in 2, 4, 8, 12 and 16 minutes post fertilization with shock duration of 20, 40, 60, 90 and 120 minutes. Hot shock was induced by 30°C bath 2, 4, 8, 12 and 16 minutes post fertilization with duration of shock 5, 10, 20, 30 and 40 minutes. Pressure shock was also tested for induction of triploidization using pressure of 70 MPa 5, 10 and 20 minutes post fertilization with duration of shock 5 minutes. Ploidy level was then determineted using flow cytometry. As a result hatchability (%), share of malformed larvae (%), share of triploid individuals (%) and yield of triploids (%) were determined. None of the experiemental shocks have led to a 100% share of triploids concerning the samples examined by flow cytometry. Best result was reached via pressure shock with duration of 20minutes which resulted with share of triploid individuals of 95% and yield of triploids 12.2+-2.5%. It must be noticed that increasing duration of pressure shock resulted in decreased hatchability and increased share of malformed larvae. Second best result was achieved via cold shock. Worst results were obtained via hot shock.
The verification of the mass induction of triploidy in brook charr in operating conditions.
ŠVAGROVÁ, Kateřina
This bachelor thesis deals with the induction of triploidy in brook trout, Salvelinus fontinalis under farm conditions using a heat- and /or hydrostatic pressure shock. The first part involves the issues of polyploidy in fish, its induction, detection methods of polyploidy and its contribution to aquaculture. The second part deals with the technological process of induction of triploidy and subsequently, with evaluation of the effectiveness of both types of the shock upon ploidy level determine by flow cytometry. In this experiment, heat shock induced 80% of triploids in contrary to the hydrostatic pressure shock inducing triploidy in 100%. The pressure shock induced triploidy in brook trout more effectively than the heat shock and provided better operational results. Moreover, pressure shock displayed better fertilization of eggs, higher hatchability, and also higher percentage of triploids.

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