Effect of pretreatment of explants and in vitro culture media in controlling infection and browning in Kusum [Schleichera oleosa (Lour.) Oken]

Abstract

The Kusum tree [Schleichera oleosa (Lour.) Oken] is being exploited in India mainly for lac production but also being known for its multiple uses like ethno-medicinal value, edible-fruits, seed oil as medicinal and biodiesel uses. But, very little attention has been given in the direction of tree improvement of this species. Moreover, in vitro propagation of woody species poses problems due to high contamination rate and exudation of phenolics. Hence, to overcome such problems, an experiment was conducted to study the effect of pretreatment of explants and in vitro culture media in controlling infection and browning in Kusum. Thus, for disinfection of explants of Kusum, nine different treatments as surface sterilants were considered. While, for controlling browning, the ten treatments consisting of different additives including antioxidants were prepared for the study. The results revealed that, the nodal explants treated with HgCl2 (0.1%) for 7 minutes and NaOCl (7%) for 5 minutes were found to be the best treatments in controlling infection (i.e., 83.33% and 70.91% respectively) in the culture media with respect to maximum survival of explants on Day 30 (i.e., 78.37% and 73.06%, respectively). On the other hand, Ascorbic acid (ranges from 100 mg L-1 to 200 mg L-1) added in MS (Murashige and Skoog) media had played a significant role and had effectively controlled the browning when compared with control. The best season for in vitro culture of Kusum was found to be the summer season mainly during the months from February to May end.