Rooting responses of rootstocks cvs. JTE-F1, M. 26 and MM. 106 were studied to different concentration of IBA in root induction media and to presence of activated charcoal in root elongation media. High rooting rate (>90%) could be achieved in cvs. JTE-H and M. 26, while cv. MM. 106 showed weak rooting ability at each IBA level tested. Incre
...asing IBA content depressed the rooting only in cv. M. 26. Presence of activated charcoal decreased considerable the rooting rate in cv. M. 26 and decreased the number of roots in cvs. JTE-H and M. 26. These cultivars developed longer roots on media containing activated charcoal, while cv. MM. 106 did not showed any reaction for it.
Tissue cultured Cymbidium PLBs (protocormlike body) were used as starting material to induce embryogenic callus which could serve as objects of genetic transformation. We obtained callus using two methods. The first method was culturing the PLB segments for one month in liquid MS medium in the presence of 0.5 mg/1 benzyladenine and 0.0
...5 mg/1 naphtylacetic acid followed by cultivation on the same composition solid medium with 0.5 g/l activated charcoal for an additional month. Callus formation was observed on 30% of the explants. The second way was to propagate the PLB segments on solid MS medium supplemented with 1 mg/1 thidiazuron. In these cultures we also observed callus formation on 20% of the explants.
Rooting of in vitro 'Royal Gala' shoots was studied under different conditions of root induction and root elongation phase. The rooting capacity was affected by both rooting phases. Very high rooting percentage could be reached with both liquid and solid root induction media. Raising the temperature from 22 °C to 26 °C during root in
...duction phase increased the rooting percentage. Presence of activated charcoal in root elongation media can affect the number of roots per rooted shoots and can increase the rooting percentage, the length of roots and the rate of survival depending also on other conditions during rooting. Presence of NAA in root elongation media reduced the number and the length of roots considerably. Favourable effect of activated charcoal on rooting was mainly due to adsorption of NAA.