The different CK-types affected differently the actual quantum
yield and the relative ETR. Y(II) and ETR changed with the concentrations similarly as in the case of maximum quantum yield
(Fv/Fm) when BA or BAR was applied as CK source. They decreased
as the concentration of BA increased and they were the highest
at 2.0 M when BAR was applied and differences were proven to
be significant statistically. Y(II) and ETR were the highest when
TOP was applied at the lowest and highest concentrations (0.5
and 25.0 M), respectively. Y(II) and ETR were the same at all
concentrations at combined application of BA and TOP. The highest Y(II) and ETR was observed at low CK concentration (0.5 M)
when BA was applied, at CU2-treatment (2.0 M) when BAR was
used, and they were significantly the lowest at CK concentrations of 2.0 and 6.0 M commonly used in axillary shoot cultures
of apple when TOP was applied in the medium. At the highest
applied CK concentration (25.0 M) no significant differences of
CK types could be proven on the Y(II) and ETR. These findings are
in accordance with our earlier findings (Dobránszki et al., 2005;
Magyar-Tábori et al., 2010) when structural and ultra-structural
changes under different CK regimes in in vitro leaves of ‘Royal Gala’
were described, a juvenile-like character of leaves was detected
after applying TOP and we assumed that these structural changes
caused by different CK supplies may be connected with functional
differences.