Optimization of Direct Somatic Embryogenesis in Ferula gummosa

Background and Objective
Direct somatic embryogenesis is a crucial technique in plant biotechnology that facilitates rapid propagation, genetic improvement, and conservation of endangered species. Unlike indirect embryogenesis, this method forms embryos directly from somatic cells without passing through a callus phase, reducing the likelihood of unwanted genetic alterations. Due to its efficiency, somatic embryogenesis is considered a superior propagation method and is influenced by various factors, including plant growth regulators. Ferula gummosa, commonly known as galbanum, is an important medicinal plant known for its valuable secondary metabolites. However, its production is facing challenges due to overharvesting and germination difficulties. These issues threaten its sustainability, making somatic embryogenesis a promising approach for cryopreservation and sustainable utilization. The present study aims to investigate the feasibility of direct somatic embryogenesis in F. gummosa and evaluate the effects of plant growth regulators on the induction and development of embryos.
Materials and Methods
To establish optimal conditions for direct somatic embryogenesis, F. gummosa seeds were collected from Abadeh, Fars Province, and stored at 4°C to preserve their viability and prevent dormancy-related decline. The seeds were sterilized, and their embryos were cultured in MS1/2 medium. After a month of cultivation, the resultant seedlings were used to prepare leaf explants for somatic embryogenesis. Leaf explants, approximately one centimeter in size, were cultured in MS1/2 medium supplemented with varying concentrations of NAA and BAP hormones. These hormonal treatments were maintained at 20°C in complete darkness for three months to prevent chlorophyll formation, thereby promoting somatic embryogenesis. The number of embryos formed in each experimental condition was recorded. The study employed a 3×3 factorial experimental design within a completely randomized design (CRD) framework, with three replications per treatment. Data analysis was performed using SPSS software to identify statistically significant variations among treatments.
 
Results
 The study revealed that NAA and BAP effectively induce somatic embryogenesis in F. gummosa. Variance analysis demonstrated that NAA concentration (P<0.01), BAP concentration (P<0.05), and their interaction (P<0.05) significantly influenced embryo formation. Comparative analysis of means indicated that the culture medium containing 0.5 mg/L NAA and 0.5 mg/L BAP resulted in the highest number of somatic embryos, making it the most effective combination for embryo induction. Additionally, the medium containing 1 mg/L NAA and 1 mg/L BAP provided favorable conditions for embryo development, yielding stronger embryos compared to other treatments. Further analysis identified 1 mg/L NAA and 0.5 mg/L BAP as the optimal concentration for embryo induction and development. These findings highlight the significance of plant growth regulators in somatic embryogenesis and emphasize the potential for refining culture conditions to improve embryo yield and quality.
Conclusion
 The results indicate that direct somatic embryogenesis using NAA and BAP is an efficient method for propagating F. gummosa. Given the prolonged seed dormancy and endangered status of this plant, somatic embryogenesis provides a viable approach for large-scale propagation, conservation of genetic resources, and restoration of natural populations. The study underscores the importance of optimizing growth regulator concentrations for improved embryogenesis and suggests that further research could explore additional factors influencing the process. These findings contribute to advancing propagation techniques for endangered medicinal plants and serve as a valuable foundation for future studies in plant tissue culture and biotechnology. By refining propagation methods, researchers and cryopreservation can ensure sustainable utilization of F. gummosa while preserving its genetic integrity and medicinal value.