Effect of Plant Hormones and Media Composition on Browning and Growth of Bacopa monnieri Callus Cultures

High phenolic content of Bacopa monnieri often causes browning of callus culture, to prevent this various hormones at different concentrations were used. 2, 4dichlorophenoxyacetic acid (2, 4-D), 1-naphthaleneacetic acid (NAA), indole-3-butyric acid (IBA) and 6-benzylamino Purine (BAP) were used in the current study. Out of these plant hormones NAA gave healthy calli without any browning. 2, 4-D was least preferable as it caused complete browning of the calli within a week. Apart from plant hormones other nutrients also played a major role in preventing the browning. The concentration of ammonium nitrate, potassium nitrate and sucrose was reduced. Reducing sucrose concentration affected the growth of the calli hence it did not help much, but reducing the amount of nitrate source in the media aided in preventing the browning. Addition of ascorbic acid (100mg/L) also stopped the browning.