Photoperiodism and plant growth regulators: optimized callus induction and regeneration in Dendrobium orchid var. earsakul

Orchids are highly valued for their beauty, diversity, and commercial importance. This study examines Dendrobium Orchid var. Earsakul, a unique mutant with significant conservation and market value, to develop faster and more efficient propagation methods than conventional techniques. Tissue culture experiments were conducted using MS medium with different combinations of plant growth regulators under varied light conditions. Kinetin with NAA produced the fastest callus induction (4 days) and highest callus biomass, while light significantly enhanced callus formation compared to darkness. For shoot regeneration, BAP with NAA resulted in the earliest shoot initiation, highest shoot number, and better shoot growth. Rooting was most effective with BAP and IBA, giving early root initiation and maximum root length. Overall, the study demonstrates the crucial interaction between light and hormones in improving micropropagation and supporting conservation and commercial production of Dendrobium Earsakul.