Rooting Induction of a Mature Pterocarpus indicus Willd. Using Stem Cuttings Derived from Stump Epicormic Shoots

Shoots arising from the stump of a mature tree of Pterocarpus indicus Willd. were used to evaluate the within-tree variation in rooting induction. Collected rejuvenated stem cuttings were separated into three different positions (base, middle, and top) and treated with various indole butyric acid (IBA) concentrations (0, 500, and 1000 ppm). Cuttings were planted in an improvised rooting chamber for rooting induction. Results of the analysis of variance achieved non-significant effects (P > 0.05) due to IBA treatment in all rooting parameters evaluated after 33 d. In contrast, a highly significant increase in the number of roots (0.93, P = < 0.001) was detected in terms of cutting position, particularly at the middle part. Similarly, apart from callus formation (P > 0.05), significant increase in percent rooting (46.83%, P = 0.0012) and number of secondary roots (0.93, P = 0.0011) were obtained from the same position. Meanwhile, nonsignificant effects were also recorded in terms of IBA and cutting position interaction, except from callus formation (P = 0.036). Means separated by DMRT revealed that the interaction effect between middle position and IBA500 ppm (0.13) and those between top position and IBA1000 ppm (0.58) were significantly different. This study has proven the presence of withinstem variation; hence, rooting responses vary in cuttings collected from epicormic shoots arising from the stump of physiologically mature P. indicus.