In Vitro Rooting of Gyrinops walla in Activated Charcoal-Containing Semi-Solid Culture and Filter Paper-Bridged Liquid Culture Systems

Plant tissue culture is the best option in producing planting material for cultivation programmes of Gyrinops walla. Perfection of in vitro rooting protocol for this species is the most decisive step in micropropagation. In the present study the effect of physical state of substrate, different concentrations of sucrose, IBA and NAA in media containing activated charcoal on in vitro rooting was investigated. In experiment-1, 0.2% (w/v) activated charcoal was added in to the ½ MS medium fortified with 30 or 40 g/L sucrose and varying concentrations of IBA or NAA (0, 0.1, 0.5, 1.0 and 2.0 mg/L). In experiment-2, filter paper-bridged liquid medium was used with 40 g/L sugar and varying concentrations of IBA or NAA (0, 0.1, 0.5, 1.0 and 2.0 mg/L). The treatments were arranged in completely randomized design with three replicates. Percentage of rooted microshoots and number of roots per shoot were recorded. The ½ MS semi-solid medium with 0.2% activated charcoal, 40 g/L sucrose and 0.1 mg/L NAA resulted in the significantly highest rooting percentage (50%)while the significantly highest number of roots (6.0) were noted in ½ MS charcoal added (0.2%) basal medium with 40 g/L sucrose and 0.5 mg/L NAA. Shoots supported with filter paper bridge on ½ MS liquid medium, supplemented with 0.5 mg/L IBA, had the highest rooting percentage (66.7%) and the highest mean number of roots per shoot (3.0) (P<0.05). Results confirmed that in vitro rooting of G. walla could be perfected by optimizing the culture medium and its constituents.