Efficient In Vitro Propagation Protocol of Swertia chirayita (Roxb. ex Fleming) Karsten: A Critically Endangered Medicinal Plant

摘要

Leaf explants of critically endangered medicinal plant Swertia chirayita were cultured in Murashige and Skoog medium fortified with various concentrations of 2,4-Diclorophenoxyacetic acid (2,4-D), 6-Benzylaminopurine (BAP) and Gibberalic acid (GA3). The best callus induction was obtained in 2,4-D (15.0 A mu M) after 60 days of culture period. After 30 days of first subculture, maximum 32 microshoots were formed in a lump of callus in combination of BAP (10.0 A mu M) with GA3 (5.0 A mu M). On the other hand maximum 25 microshoots were formed from a lump of callus in BAP (5.0 A mu M) used alone. The multiple shoots developed in combination of BAP with GA3 were found poor/thin in comparison to BAP alone. Therefore, the further subculture was conducted in BAP (5.0 A mu M) and approximately 210 microshoots per lump of callus were obtained within 3-4 months of culture. Root induction was observed in all microshoots cultured in various concentrations of auxins (Indole-3-butyric acid, IBA and Indole-3-acetic acid, IAA) after 45 days of culture, however, the higher mean number of roots (50) per microshoot were formed in IBA (5.0 A mu M). After a month, well rooted plantlets were successfully transplanted and established (58.70%) in mixture of soil, sand and FYM (2:1:1) under partially shade (75% agro shade net) condition in nursery at Pothibasa (2200 m a.s.l.).