Optimization of Sucrose Concentration and Light Treatment in Cell Suspension Culture Establishment of Barringtonia racemosa L.

Objective: This study was carried out to optimize the concentration of sucrose and light treatment for the establishment of cell suspension cultures with the greatest records of dry cell biomass. Methods: The homogeneous cell suspension cultures of B. racemosa cultured in MS (Murashige & Skoog’s) media with 1.0 mg/l 2,4-D (2,4-dichlorophenoxyacetic acid) and 1.5 mg/l kinetin were optimized for sucrose concentrations (2.0, 3.0 & 4.0% w/v) and light treatment (24-hour light or 24-hour dark). The dry cell biomass and pH values were recorded for 30 days. The data gathered were plotted against time and statistically analysed by analysis of variance (ANOVA). Results: The supplementation of 4.0% sucrose in 24-hour dark treatment recorded the most optimum dry cell biomass record. The different phases of cell growth could be identified from the growth curve constructed based on dry cell biomass records. The first two-day duration was identified as lag phase in all treatments tested followed by growth exponential phase and constant growth in cells until they achieved their maximum dry cell biomass. Afterwards, some of the treatments underwent rapid declining phase while others showed a short duration of stationary phase by depicting a plateau stage in the cell kinetic plot before finally entering the declining phase afterwards. It has been observed that the cells treated in the dark achieved their highest record of dry cell biomass earlier than those treated in the presence of light in the cultures supplemented with 3.0% and 4.0% sucrose. The effects of variations in sucrose concentration and light treatment were generally significant (p < 0.05) on dry cell biomass but were insignificant generally towards pH values (p> 0.05). Novelty/Improvement: A protocol for the establishment of cell suspension cultures of B. racemosa and the importance of sucrose and light treatments towards cell growth had been developed and highlighted.