A Comparative Analysis among Different Surface Sterilisation Methods for Rice Invitro Culture

Invitro tissue culture establishment is the most important phase in rice (Oryza sativa L.) genetic improvement studies. But, invitro tissue growth demands a sterile condition conducive for unhampered nutrient supply to the explant which otherwise face competition from unwanted microbial contamination of explant origin. To eliminate such contaminants, there are several surface sterilisation techniques available for Invitro culture establishment of mature rice seed explants, which include the application of either mercuric chloride or sodium hypochlorite as sterilizing agents. Therefore, a comparative study was conducted to determine the effect of these sterilization techniques on decontaminating the rice seed explants without affecting their invitro germination potential. The most effective sterilisation was obtained with 0.2% mercuric chloride treatment for 8 minutes, which produced 93.62± 0.191% of contamination free seeds. But, the highest germination (94.53± 0.210%) was obtained with 4% of NaOCl treatment for 10 minutes. The results demonstrated that the level of contamination decreases with increasing concentration of sterilising agents and the duration of the treatment. The germination percentage decreased with increasing concentration of mercuric chloride. Sodium hypochlorite enhanced germination until a concentration increase of 4% and then the germination percentage decreased with increasing concentration and treatment duration. These findings may help in determination of most appropriate surface sterilisation technique in rice for in vitro culture.