Efficient Plant Regeneration of Cymbidium aloifolium (L.) Sw., a Threatened Orchid of Nepal through Artificial Seed Technology

Artificial seed technology is a method of considerable potential for mass propagation and conservation of rare, endangered and threatened species. In the present investigation, artificial seeds were obtained through encapsulation of three weeks old protocorm (3.0 ± 1.0 mm diameter) of Cymbidium aloifolium with calcium alginate. Artificial seeds were cultured on liquid Murashige and Skoog (MS) or Knudson (Kn C) medium at different strength (×1.0, 0.5, 0.25) and full strength (1.0) of both media supplemented with 0.5 mg/l 6-benzyl aminopurine (BAP) and 0.5 mg/l α-naphthalene acetic acid (NAA). Full strength of MS medium without plant growth regulators was found to be the most favourable condition for efficient plantlet regeneration of C. aloifolium (9.83 shoot and 2.66 roots per culture). The storage potential of artificial seed was tested at 4°C and room temperature (RT, 21°C ± 2°C) for up to 90 days on both media and found 83.33% viability at 4°C storage on MS media. Eighty five percent of plantlets regenerated from artificial seeds culture were successfully hardened in a potting mixture of cocopeat, clay and sphagnum moss (2:1:1). Hence, the methodology can be used for propagation and conservation of C. aloifolium through artificial seed system.

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

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 ℃.In order to check the viability,storage artificial seeds were treated with five different sterilization techniques(T_1 T_2,T_3 T_4,T_5) and inoculated on full strength(1.0) of MS liquid medium after each 7 d of interval upto28 th 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 ℃ till 28 th days.Treatments T_1 and T_2showed 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.