Effect of Nitrogen on in Vitro Propagation of Endangered Medicinal Plant: Swertia Chirayita Roxb. Ex Flaming

Abstract

The effect of nitrogen was investigated on the organogenesis of Swertia chirayita (Gentianaceae) to overcome the challenges related to its cultivation. The best callogenic response was observed on root explants inoculated onto MS medium supplemented with BAP (2.0 mg/l) along with 2,4-D (0.5 mg/l) after 35 days of culture. Subsequent transfer of callus for multiplication on the same media composition under complete darkness presents the best results in terms of callus multiplication. Callogenic cultures were subculture onto modified MS medium supplemented with inorganic nitrogen sources, i.e., NH4NO3 (14-56N/l), KNO3 (100-400N/l) with BAP (3.0 mg/l) were observed. Organogenic response (52%) was observed after 8-12 weeks of culturing. The maximum number of the shoot was recorded on MS medium with NH4NO3 (28 N/l), KNO3 (300N/l) with BAP (3.0 mg/l). Moreover, 90% of them were able to regrow when sub-cultured on the same media. Sixteen weeks old multiple shoots were subcultured on MS medium supplemented with different auxins. IAA was proved to be the best hormone rooting purpose. However, the best rooting response regarding the number of roots and an average length of roots was obtained at IAA (1.0 mg/l). Survival of 90% was achieved when rooted plantlets were successfully established in substrate containing sand, vermicompost, and garden soil in equal proportion for hardening and acclimatized.