PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

Coriandrum sativum L. (coriander) is a high-value seed spice renowned for its distinctive aroma, culinary versatility, medicinal importance, and rich reservoir of bioactive metabolites. The present investigation was undertaken to develop an efficient in vitro system for indirect organogenesis through hypocotyl-derived callus and to explore the biochemical potential of callus tissues under diverse plant growth regulator (PGR) regimes. Forty-five combinations of 2,4-dichlorophenoxyacetic acid (2,4-D), 6-benzylaminopurine (BAP), and kinetin were evaluated using a completely randomised design with four replications. Hypocotyl explants of coriander cultivar ACr-3 were cultured on Gamborg’s B5 medium under aseptic conditions, and variations in biomass accumulation and biochemical constituents were assessed. Substantial treatment-dependent differences were observed, highlighting the influence of PGR balance on callus growth and metabolite accumulation. Among the tested treatments, T35 (2,4-D 1.5 mg L⁻¹ + BAP 1.0 mg L⁻¹ + kinetin 0.5 mg L⁻¹) produced the highest fresh biomass (2.790 g) and dry biomass (1.953 g). Treatment T41 recorded the maximum total phenolic content, T33 exhibited the highest flavonoid accumulation, and T44 showed superior antioxidant activity. The maximum chlorophyll and carotenoid contents were recorded under T15. Although the tested regeneration media did not induce complete shoot regeneration, the development of embryogenic callus revealed promising morphogenic competence. Overall, the study demonstrates that appropriate PGR combinations can substantially enhance callus biomass and biochemical potential in coriander. The optimised protocol provides a valuable platform for in vitro metabolite production, germplasm conservation, micropropagation, and future genetic improvement of this economically important spice crop.