Results indicated that 3-week-old in vitro apple shoots have a
well-developed and functional photosynthetic apparatus, however,
its maximal quantum yield and efficiency depended on the CKsource of the medium. At low CK concentration (0.5 M) the highest
maximum quantum yield and photochemical efficiency (Fv/Fmand
Fv/F0) were caused by application of BA, however, when CKs were
applied at concentrations (CU2- and CU6-treatments) commonly
used during axillary shoot multiplication of apple, the highest Fv/Fm
and Fv/F0tended to be achieved if BAR was applied in the medium
and this was proven statistically at CU6-treatment (6.0 M). At high
concentration (25.0 M) of CK no significant differences could be
detected in the values of Fv/Fmand Fv/F0, respectively, caused by
different CK types (Fig. 1A and B).