Screening of Some Chemical Disinfectants for Media Sterilization During In Vitro Micropropagation of Sugarcane

Abstract

Three antimicrobial compounds viz. mercuric chloride (HgCl₂), sodium hypochlorite (NaClO) and bleaching powder, (CaOCl₂) were tested at various concentrations to find out an effective chemical agent for sterilization of nutrient media for in vitro micropropagation of sugarcane. The best result was obtained in presence of NaClO at 0.1 % concentration where maximum 96 % shoot cultures were found contamination free, grew normally and were comparable to the cultures grown on autoclaved nutrient medium (control). Mercuric chloride (0.1 %), though prevented microbial contamination in about 85 % cultures, the shoots remained green for 4–7 days only and thereafter gradually turned brownish-yellow, showed rotting appearance and ultimately approximately half of the sterile shoots died within next one week. No microbial contamination was observed at higher concentrations (0.15 and 0.2 %) of HgCl₂ and NaClO both, however the survival and growth of shoots were affected adversely. None of the chemicals was able to prevent microbial contamination up to the desired extent at concentrations below 0.1 %. Shoot cultures could be micropropagated successfully up to 10 subcultures (cycles) on medium supplemented with 0.1 % of NaClO, without any adverse effect on shoot growth. Addition of NaClO in rooting medium at a concentration of 0.1 % was also found equally effective. The results suggested that chemical sterilization of media with sodium hypochlorite, can be a cost effective option of autoclaving during micropropagation of sugarcane at commercial scale.