University of Guilan Iranian Journal of Seed Sciences and Research 2476-3780 8 1 2021 03 21 Seedling growth optimization and investigation of taxane production in Taxus baccata L. via in vitro culture Seedling growth optimization and investigation of taxane production in Taxus baccata L. via in vitro culture 77 89 5212 10.22124/jms.2021.5212 FA Mahsa Bamneshin Ph.D. Student, Department of Biotechnology, Agricultural and Natural Resources College, Pardis of Guilan University, Guilan, Iran Abdolah Hatamzadeh Professor., Department of Horticultural Sciences, Agricultural College, Guilan University, Guilan, Iran Mohammad Reza Naghavi Professor., Department of Agronomy and Plant Breeding, Agricultural and Natural Resources College, Tehran University, Tehran, Iran Mohammad Hossin Mirjalili Associate Professor., Department of Agriculture, Medicinal Plant and Drugs Research Institute, Shahid Beheshti University, Tehran, Iran Journal Article 2020 04 02 Yew (<em>Taxus baccata</em> L.) has diterpenoid compounds with anti-cancer effects therefore it is one of the most well-known medicinal plants that is in danger of extinction. In this study, which was conducted at the Research Institute of Medicinal Plants of Shahid Beheshti University, the effect of culture medium (MS, 1/2MS and NN), phenolic absorbents (PVP and activated charcoal) and plant growth regulators (IBA, GA₃ and BA) was investigated in a factorial design with three replications, with the aim of improving germination and growth of seedlings in in vitro culture. In the following, taxane production was measured in plantlets that were grown in select medium for ten months. According to our results, NN culture medium due to lower concentration of basal salts had no significant effect on germination percentage but increased root length and normal seedling growth percentage. Also supplementing the media with phenolic absorbent extended root length and shoot height as well as increasing normal seedling growth rate. In using PGRs, the highest normal seedling growth rate, shoot height and root length was obtained respectively from IBA × GA3 (0.2 mg/l gibberellic acid × 0.01 mg/l indole butyric acid), IBA × BA (0.2 mg/l gibberellic acid × 2 mg/l benzyl adenine) and 0.1 mg/l indole butyric acid, while PGRs had no significant differences in germination rate. Also, the amount of taxan in the aerial part was higher than the root and the highest taxan in the aerial part was 10-deacetylbaccatinIII  and in the root were taxol and 10-deacetyltaxol, the maximum of all was achieved at the end of the experiment. Overall, the results indicate the positive effect of activated charcoal, PGRs and reducing culture medium macronutrients on root length, shoot height and the normal growth process of <em>Taxus baccata</em> seedling, in order to increase the yeild of yew propagation under in vitro culture condition. The cell culture obtained from the aerial part is much better than the hairy root cell culture.  Yew (<em>Taxus baccata</em> L.) has diterpenoid compounds with anti-cancer effects therefore it is one of the most well-known medicinal plants that is in danger of extinction. In this study, which was conducted at the Research Institute of Medicinal Plants of Shahid Beheshti University, the effect of culture medium (MS, 1/2MS and NN), phenolic absorbents (PVP and activated charcoal) and plant growth regulators (IBA, GA₃ and BA) was investigated in a factorial design with three replications, with the aim of improving germination and growth of seedlings in in vitro culture. In the following, taxane production was measured in plantlets that were grown in select medium for ten months. According to our results, NN culture medium due to lower concentration of basal salts had no significant effect on germination percentage but increased root length and normal seedling growth percentage. Also supplementing the media with phenolic absorbent extended root length and shoot height as well as increasing normal seedling growth rate. In using PGRs, the highest normal seedling growth rate, shoot height and root length was obtained respectively from IBA × GA3 (0.2 mg/l gibberellic acid × 0.01 mg/l indole butyric acid), IBA × BA (0.2 mg/l gibberellic acid × 2 mg/l benzyl adenine) and 0.1 mg/l indole butyric acid, while PGRs had no significant differences in germination rate. Also, the amount of taxan in the aerial part was higher than the root and the highest taxan in the aerial part was 10-deacetylbaccatinIII  and in the root were taxol and 10-deacetyltaxol, the maximum of all was achieved at the end of the experiment. Overall, the results indicate the positive effect of activated charcoal, PGRs and reducing culture medium macronutrients on root length, shoot height and the normal growth process of <em>Taxus baccata</em> seedling, in order to increase the yeild of yew propagation under in vitro culture condition. The cell culture obtained from the aerial part is much better than the hairy root cell culture.  https://jms.guilan.ac.ir/article_5212_6486bf0acbbc89c25cc97cc88833f1b8.pdf