Effects of Surface Sterilizing Agents, Sucrose and Plant Growth Regulatory Hormone Concentration Levels on Micropropagation of Bacopa monnieri L.

Abstract

Background and Aims: Bacopa monnieri L. is used to treat sleep deprivation and anxiety. Microropagation is rapid and helps in exsitu preservation of this endangered plant. Methods: Three surface sterilizing agents with different concentrations [ethanol (EtoH; 50 and 70%), mercuric chloride (HgCl2; 0.1 and 0.5%) and sodium hypochloride (NaOCl; 0.1, 0.5 and 1%)] were used at different time intervals (1, 3, 5, 8 and 10 minutes) with and without hot water to obtain the good aseptic culture. Various concentrations of sucrose (30, 10 and 20 g/L) plus agar 7 g/L was used to observe the effect on root initiation and length in Bacopa monnieri L. The initiated explants (leaf, node and internode) were cultured on MS media and supplemented with different combination of 2, 4-D (2, 4-dichlorophenoxyacetic acid), KIN (Kinetin) and BAP (6-Benzyl amino purine), IAA (Indole-3-acetic acid), NAA (1-Naphthaleneacetic acid) and GA3 (Gibberellin A3) to induce callus, to initiate root and root length, to initiate auxillary bud induction and length and to  multiple shoots after inoculation. Results: It has been seen that 0.1% of HgCl2 (Mercuric chloride) followed by warm water showed 100% aseptic culture conditions. MS media with sucrose (30 g/L) along with agar (7 g/L) showed multiple root initiation whereas MS media with 2,4-D (0 mg/L), KIN (2.0 mg/L) and BAP (2.0 mg/L); NAA (1.0 mg/L) + (KIN 1.0 mg/L) + BAP (1.0 mg/L) and  BAP (2.0 mg/L) + KIN (1.0 mg/L) + GA3 (0.5 mg/L) were found good for rapid callus growth, shoot length and multiple shoots respectively. Conclusions: In conclusion, higher number of roots and increased root length was observed in MS Media + Sucrose (30 g/L) + Agar (7 g/L). It was also found that in the medium MS + 2,4-D (0 mg/L), KIN (2.0 mg/L) and BAP (2.0 mg/L) rapid callus growth was observed which turned pale  yellow and of globular appearance. Highest shoot length was observed in MS + NAA (1.0 mg/L) + (KIN 1.0 mg/L) + BAP (1.0 mg/L) medium. Maximum number of multiple shoots was found in MS + BAP (2.0 mg/L) + KIN (1.0 mg/L) + GA3 (0.5 mg/L).