In vitro propagation, antioxidant and antimicrobial activities of Tripleurospermum baytopianum (Asteraceae): a threatened endemic species in Türkiye

In this study, a rapid and efficient in vitro propagation protocol has been established for threatened endemic species Tripleurospermum baytopianum (Asteraceae) growing naturally in Türkiye in Murashige and Skoog basal medium (MS) using nodal explants. The achenes evaluated as initiation material reached the highest germination success of 76.7 % in MS medium supplemented with 1.0 mg L^-1 gibberellic acid (GA₃). MS medium containing 1.0 mg L^-1 6-BA and 0.1 mg L^-1 IBA was found to be the best medium to stimulate and sustain the new shoot formation (8.3 shoot number per explant). This medium was also more effective in terms of callus formation, fresh and dry weight parameters per explant with 87.8 %, 1.74 g and 0.111 g, respectively. MS basal medium enriched with 0.5 mg L^-1 2iP plus 0.1 mg L^-1 NAA achieved 74.7 mm shoot length per explant was quite remarkable. Rooting success was achieved between 86.7 % and 100 % in all rooting media. The acclimatization process of the plantlets was carried out successfully with 75 % survival rates in botanical garden. Cytogenetic analysis revealed that propagated plants have the same chromosome number (2n = 2x = 18) with their mother plants in natural population, indicating genetic stability. Screening of the antioxidant (DPPH scavenging) and antimicrobial (disc diffusion) activities of ethanolic extracts of in vitro propagated plants were also carried out and compared with that of the wild-grown plants (mother plants). The biochemical tests showed that in vitro propagated plants and the mother plants have almost the same antioxidant activities, indicating metabolic stability. On the other hand, although statistically the highest antimicrobial activity was in sample 20 and sample 1 (taken from nature), it can be said that the high amount of cytokinin relatively increases the antimicrobial activity. The study signifies a notable in vitro production technique for T. baytopianum and provides an important comparison method of the antioxidant and antimicrobial potentials of in vitro derived shoots and mother plants of threatened endemic T. baytopianum.