Effect of 2, 4-D, BAP, KN, IAA and IBA onin vitroRegeneration ofOcimum canumSims – An Important Hoary Basil Plant

Abstract

The effect of 2, 4-dichlorophenoxyacetic acid (2, 4-D), 6-benzylaminopurine (BAP), kinetin (KN), IAA (indole-3-acetic acid) and indole-3-butyric acid (IBA) was evaluated for in vitro shoot regeneration of Ocimum canum Sims. This important medicinal plant species belongs to the family Lamiaceae and it is also known as hoary basil. Nodal segment explants were cultured on Murashige and Skoog (MS) medium containing different phytohormones. 2, 4-D resulted in callus induction from nodal segments when supplemented with MS medium. The highest callus induction (90.17%) was recorded on MS medium containing 2, 4-D (2 mg/l). When nodal segments were cultured on MS medium supplemented with BAP (0.5–2.0 mg/l), KN (0.5–2.0 mg/l) as sole and with combination of BAP (0.5 mg/l) and IAA (0.10–1.00 mg/l), multiple shoots proliferation was initiated. The maximum number of shoots (12.75±0.64), with average length 6.04±0.08 cm, was recorded with MS medium containing BAP (1.5 mg/l) as sole. Repeated subculture of in vitro proliferated shoots yielded 35–40 shoots from a single nodal segment explant after 4–5 months. Developed single shoots were transferred for rooting to ½ MS medium containing IBA (1.5 mg/l) for best rooting of each shoot (3.99±0.23). The regenerated plantlets with well-developed roots were transferred to plastic pots containing a mixture of garden soil, farm yard manure and sand (1:1:1) in controlled environment for achieving high survival percentage (80 – 85%). Thus, a comprehensive micropropagation protocol was developed for O. canum Sims first time using nodal segment explants. This protocol can be used for commercial propagation and for future genetic improvement studies.