Abstract: Pterocarpus marsupium Roxb., commonly known as Indian kino, Vijaysar or Bijasal, is a valuable medicinal and multipurpose tree of the family Fabaceae. Its bark, heartwood and other tissues are associated with a diverse range of bioactive constituents, including phenolic compounds, flavonoids and stilbenes. Increasing demand for medicinal raw material, destructive harvesting of mature tissues and limited natural regeneration emphasize the need for reliable clonal propagation and conservation technologies. Conventional seed propagation may be constrained by seed availability, dormancy and variability, whereas in vitro propagation offers a controlled approach for rapid multiplication of elite or pharmacologically valuable material. The experimental framework compares cytokinins including 6-benzyladenine (BA/BAP), kinetin and meta-topolin, alone and in combination with low concentrations of auxins such as indole-3-acetic acid (IAA), indole-3-butyric acid (IBA) or α-naphthalene acetic acid (NAA). Root induction is evaluated using IBA-based treatments, including direct rooting and a two-step pulse-treatment strategy. Response variables include percentage of responding explants, number of shoots per explant, shoot length, number of nodes, rooting percentage, number of roots per shoot, root length and survival during acclimatization. BA-based nodal culture, BA–IAA combinations, BA–NAA systems, immature zygotic embryo culture and meta-topolin systems have all produced multiple shoots, while IBA-based pulse treatments have repeatedly improved rooting. The objective of the proposed optimization is therefore not simply to identify the PGR that produces the greatest number of shoots, but to establish a balanced multiplication system that provides elongated, physiologically competent shoots capable of efficient rooting and ex vitro establishment.

Keywords: Pterocarpus marsupium; Indian kino; micropropagation; tissue culture; Murashige and Skoog medium; 6-benzyladenine; meta-topolin; NAA; IBA; shoot multiplication; rhizogenesis; acclimatization.