Duration for callus propagation of indica rice (Oryza sativa L.) cultivar Sangyod in suspension culture

Abstract

Calli of indica rice (Oryza sativa L.) cultivar Sangyod were propagated in a liquid culture medium containing 4.10 gL-1 modified Chu/Gamborg (NB) basal medium, 1 gL-1 Lproline, 2 mgL-1 2,4-dichlorophenoxy acetic acid (2,4-D), 1 mgL-1 1-naphthalene acetic acid (NAA) and 30 gL-1 sucrose, maintained in shaker flasks (25±2°C, 100 rpm, under light for 27 days. Day 12 was found to be the best time for callus propagation, indicated by fresh mass (F.M.) doubling time (td) 11.73 day-1 and the highest cell density up to 66.83 gL-1 F.M. and 4.98 gL-1 dry mass, in the exponential phase. The productivity was 2.61 gL-1day-1 F.M. and yield of cell mass (Yx/s) was 1.08 gcellg-1 glucose F.M. The specific growth rate (μ) was 0.06 day-1 F.M.This data can be used to choose the optimum time for repeated subculturing callus to increase the productivity of high cell density cultures and it is an important for further study the physiological and morphological differentiation of cell suspension culture, improving plant regeneration systems.