2.2. Tests of culture mediaThe two media used in the experiment, MS (Murashige and Skoog,1962) and Orchimax including activated charcoal (Duchefa Biochemie B.V, Netherlands) were completely different in the content ofmacro- and micronutrients, vitamins and inorganic compounds(Table 1). Four media combinations were tested: MS and Orchimaxwithout growth regulators "000, and the same two supplemented with0.5 mg¢L1 BA. As preliminary tests indicated that the standardsucrose concentration of 30 g/L causes plant death, 15 g/L sucrosewas added to the MS medium. Media are solidified with 5.5 g¢L1Gelrite, the pH was adjusted to 5.8 with HCl and NaOH, beforeautoclaving. The 250 ml jars filled with 50 ml of the medium wereclosed with transparent plastic covers and autoclaved for 18 min at121 °C and 110 kPa. The jars were transferred into the phytotronunder 22§1 °C, 16 h day with light of 35 mmol m2 s1 PPF, providedby fluorescent lamps.The combination consisted of 10 (replicates) of 5 plants each (50plants per combination). The percentage of regenerating explants,percentage of rooted explants, the number of new plants and theirlength were evaluated after eight weeks.