In vitro germination and propagation of a threatened medicinal orchid, Cymbidium aloifolium (L.) Sw. through artificial seed

Abstract

Objective: To study the in vitro germination and plantlet regeneration from artificial seeds of Cymbidium aloifolium (C. aloifolium), a highly threatened medicinal orchid of Nepal. Methods: Artificial seeds were produced in vitro by encapsulation of protocorms with 4% sodium alginate and 0.2 mol/L calcium chloride solution. In vitro germination and plantlet regeneration of the artificial seeds were tested by culturing them on different strength of Murashige and Skoog (MS) liquid media (0.25, 0.5 and 1.0) and MS liquid medium supplemented with 0.5 mg/L benzyl amino purine and 0.5 mg/L naphthalene acetic acid. Freshly produced artificial seeds were stored up to 28 d at 4 ºC. In order to check the viability, storage artificial seeds were treated with five different sterilization techniques (T1, T2, T3, T4, T5) and inoculated on full strength (1.0) of MS liquid medium after each 7 d of interval upto 28th days. Results: The highest percentage of germination (100%) of artificial seed was obtained on quarter (0.25), half (0.5) and full (1.0) strength of MS liquid medium. Experimentally, full strength of MS liquid medium was more effective for earlier seedling development of C. aloifolium. Artificial seeds were successfully stored at 4 ºC till 28th days. Treatments T1 and T2 showed 97.5% viability of storage artificial seeds and hence considered as the most effective sterilization techniques to recover the plant from storage artificial seeds. Plantlets developed from artificial seeds were successfully acclimatized in potting mixture containing cocopeat, litter and sphagnum moss with 85% survival rate. Conclusions: The present study revealed that artificial seeds are the good alternative explants for in vitro mass propagation and short term conservation of C. aloifolium.

Keywords

• Media
• Propagation
• Protocorms
• Encapsulation
• Artificial seed