Optimization of juvenile safflower (Carthamus tinctorius L. cv. Safir) shoot cultures in semi-solid medium and propagation in temporary immersion bioreactor systems (TIS)

This thesis aims to determine the optimal conditions for the in vitro propagation of safflower (Carthamus tinctorius L. cv. Safir) shoots in both semi-solid media and temporary immersion bioreactor systems (TIS). In the first stage of the study, different culture media types (MS, SH, and Gamborg), carbon sources (sucrose, glucose, maltose), and combinations of cytokinins (BAP, KIN, and TDZ) with NAA were tested. The results demonstrated that the combination of full-strength 1X MS medium, 30 g/L sucrose, and 2 mg/L BAP + 0.5 mg/L NAA yielded the best performance in terms of regeneration rate (100%), shoot length (2.80±0.21 cm), and shoot/explant ratio (1.33±0.15). Additionally, the combination of 1X MS medium, 30 g/L sucrose, and 2 mg/L TDZ + 0.5 mg/L NAA also provided comparable results, achieving high regeneration rates (100%), shoot lengths (2.30±0.20 cm), and shoot/explant ratios (1.33±0.19). However, when comparing the two combinations, the combination of 2 mg/L BAP + 0.5 mg/L NAA was preferred for adaptation to liquid media due to its longer survival and superior regeneration ability. In the second stage, the optimized protocol from the semi-solid medium was evaluated in a liquid medium using a temporary immersion bioreactor system (RITA®). In this context, the effects of different immersion durations (8, 16, 24 hours) and frequencies (8, 16, 24 minutes) on shoot development were investigated. The results indicated that the highest shoot length (1.69±0.19 cm) and the best shoot/explant ratio (1.21±0.11) were achieved with the 24-hour immersion and 16-minute frequency (24h/16m) protocol. Considering all morphological data and practical application aspects, the 24h/16m protocol was found to provide superior performance, maintaining a low vitrification rate and being the most suitable option in terms of practicality. This study developed an effective, scalable, and efficient method for safflower shoot proliferation using semi-solid media and temporary immersion bioreactor systems. TIS emerged as a viable alternative for mass production and provided a significant foundation for enhancing the agricultural and industrial potential of safflower.