Optimization of the in vitro micropropagation protocol for sea buckthorn, Hippophae rhamnoides to improve planting material productivity

Elderberry, Hippophae rhamnoides is a valuable plant with medicinal, food and soil conservation applications, but its traditional propagation is limited due to problems such as genetic heterogeneity of seeds and difficulty in rooting cuttings. This study aimed to systematically optimize the in vitro micropropagation protocol to increase the efficiency of producing uniform and high-quality nursery stock of this plant. Optimization was performed in three main stages of establishment, propagation and rooting using nodal explants. The results showed that in the establishment stage, the use of Murashige and Skoog (MS) medium with half strength of macroelements along with ۱ mg L-۱ benzylaminopurine (BAP) had the best results, resulting in ۹۲% survival and ۸۳% initiation of branching. In the propagation stage, the combination of ۲ mg L-۱ BAP with ۰.۲ mg L-۱ auxin naphthalene acetic acid (NAA) in complete MS medium produced the highest propagation coefficient (۶.۷ lateral branches per explant) and the highest quality branches without the problem of vitrification. At the rooting stage, the rapid immersion method for ۳۰ seconds in ۱ mg L-۱ auxin indole-۳-butyric acid (IBA) solution and then transfer to hormone-free medium was superior to continuous cultivation in auxin-containing medium, with ۸۷% rooting and formation of healthy and branched root systems. Incorporating these optimal conditions into an integrated protocol resulted in a significant increase in overall efficiency. The final propagation rate increased from about ۱ seedling per explant in the basic protocol to more than ۵.۳۶ seedlings. Also, the time for each complete micropropagation cycle was reduced to ۴ weeks. The seedlings obtained from the optimized protocol had excellent morphological vigor, which was confirmed by their ۹۳.۳% survival rate during the adaptation phase in the greenhouse. This optimized protocol provides an effective tool for mass and clonal production of superior elderberry genotypes.

کلیدواژه ها:

Micropropagation ، Elderberry ، Hypophe rhamnoides ، Protocol optimization ، Plant hormones ، Adaptation