Manisha Hariwal, Shweta Verma, Sanjay Kumar
This experimental study aimed to evaluate the effect of colchicine on phenolic content, flavonoid content and antioxidant activity in AF-1 and AF-2 genotypes of Foeniculum vulgare Mill. (Fennel). Additionally, it also determines the optimal concentration of colchicine which could potentially be used to induce polyploidy. The experiment employed colchicine concentrations ranging from 0.0125 % to 0.2 % for 24 and 48 h. DPPH, H₂O₂, and FRAP, alongside total phenol content (TPC) and total flavonoid content (TFC) were assayed to compare the radical scavenging activities (RSA) of control and colchicine-treated fennel groups. Moderate treatments (0.0125–0.05 %) for 48 h elicited the most pronounced biochemical responses. DPPH scavenging percentage was found to be maximum (71.87 %) in AF-2 at 0.05 % 48 h followed by 69.07 % in AF-1 at the same treatment. % inhibition of H 2 O 2 showed the highest scavenging percent at 0.05 % 48 h in AF-2 (27.22 %) and AF-1 (26.17 %) genotypes. The FRAP assay represented greatest reducing antioxidant power for AF-2 (19.53 %) and AF-1(9.86 %) at similar treatment condition. These findings suggest that colchicine can enhance antioxidant capacity in fennel at specific doses, positioning the treated genotypes as promising sources of natural antioxidants for pharmaceutical applications. Nevertheless, future research integrating cytogenetic validation is required to confirm polyploidy induction and to further characterize the biochemical and therapeutic potential of colchicine-induced metabolic modulation in fennel. • Colchicine treatment induced stress responses in Foeniculum vulgare plants. • Phenolic, flavonoid and antioxidant levels significantly increased in treated extracts. • 0.05 % colchicine for 48 h yielded optimal response among the tested conditions. • Colchicine may improve the biochemical stress tolerance in F. vulgare at low doses. • Colchicine treatment offers a strategy to boost medicinal plant quality.