Effects of Thin Cell Layer Technique and Nutrient Media Contents of Regeneration and Browning Characteristics of the Laurus nobilis L. Explants

The aim of this study is in order to investigate the effects of explant source, explant type and MS media composition containing different concentrations of sucrose, activated carbon and Coconut milk for regeneration and browning of Laurus nobilis L. using thin cell layer (TCL) culture system. A higher rate of callus (57.15%) and shoot (2%) regeneration and a lower rate of blackening were determined in transversely cut stem TCL explants compared to leaf explants. While 1.33% callus regeneration was achieved in leaf explants; shoot regeneration could not be achieved. While more callus regeneration (35.17%) was found in explants taken from the field, more shoot regeneration (1.5%) and lower rate of browning were obtained in explants taken from in vitro. In the sugar trials, the highest callus regeneration (40.83%) was defined in MS medium containing 30 g/L sucrose supplemented with 1 mg/L BAP, and the highest shoot regeneration (2.5%) was determined in MS medium containing 45 g/L and 60 g/L sucrose supplemented with 1 mg/L BAP. When explant type, explant source and nutrient media composition are considered together; the highest callus regeneration (100%) was obtained in field-sourced stem TCL explants cultured in medium containing 25 mL/L coconut milk and 1 mg/L BAP. The highest shoot regeneration (6.6%) was determined in in vitro stem TCL explants cultured in MS media containing 30, 45, 60 g/L sucrose and 1 mg/L BAP. The lowest percentage of browning (50%) was obtained from in vitro stem TCL explants cultured in MS medium containing 2 g/L activated carbon and 1 mg/L BAP.