High-Frequency Shoot Regeneration From Flower Bud Derived Callus of Gymnostachyum Febrifugum Benth., an Endemic Medicinal Plant to the Western Ghats

Abstract

Gymnostachyum febrifugum Benth. is a small, scapigerous, rare and endemic medicinal herb indigenous to India belonging to the family Acanthaceae. This study reports an efficient protocol for high-frequency flower bud derived callus induction and shoot organogenesis in G. febrifugum. Flower buds at 7d before anthesis (dBA) were excised from the inflorescence and cultured on MS medium supplemented with various concentrations of 2, 4-dichlorophenoxy acetic acid (2, 4-D; 0.5-2.0 mg/l) for callus induction. The optimum callus induction (78%) was obtained on MS medium supplemented with 1.5 mg/l 2, 4-D. The calli when subcultured on MS medium supplemented with different concentrations of thidiazuron (TDZ; 0.5-2.5 mg/l) or 6-benzylaminopurine BAP (0.5-2.5 mg/l) alone or in combination with 1- naphthaleneacetic acid (NAA; 0.2-0.7 mg/l) induced shoots. The highest frequency (94%) and number of shoots (44.6 shoots/unit callus) were obtained on MS medium supplemented with 2.0 mg/l TDZ and 0.5 mg/l NAA. The optimum rooting frequency (95%) and number of roots (10.2) were observed on ½ MS medium supplemented with 3.0 mg/l indole-3- butyric acid (IBA). The rooted plantlets were acclimatized and transferred to soil with 94% success.