Effect of various concentrations of different growth regulating hormones on callus weight and the amount of thymol of Thymus daenensis

Thymus daenensis is a perennial plant belonging to Lamiaceae family that is a species endemic to Iran. Due to the indiscriminate use of this plant which possesses medicinal values, T. daenensis tissue culture is suggested to increase the quality and quantity of its effective compounds. Callus cultures using leaf and stem explants were subjected to different hormonal treatments. Ten-millimeter explants of leaves and stems were cut up from sterile seedlings. MS medium was used with different concentrations of naphthalene acetic acid, benzyl amino purine, kinetin and 2,4-D (mg per liter) in which callus formation was observed. The highest level of thymol (28/1335 micrograms per gram) was recorded in calluses derived from leaf explants whereas the lowest level was observed in calluses obtained from stem explants. Also the highest levels of thymol, i.e. 65/1313 and 30/1322 micrograms, were observed in treatments of 0.4 NAA BAP and 0.8 NAA BAP mg per liter, respectively. Moreover, the interaction of effects of different treatments of calluses and different concentrations of hormones showed that the highest level of thymol (38/1345 micrograms per gram) was obtained from the treatment of NAA.5 BAP 0.2 mg per liter in the calluses derived from leaf explants. In addition, the maximum callus weight (22.1 grams) was related to the treatment of 0.8 NAA BAP milligrams per liter. Results of the callus culture of T. daenensis to enhance the quality and quantity of its active ingredients showed that different explants and hormones with different concentrations and as well as their interactions had a significant effect on the level of thymol and callus weight (p≤0.01).