Response of Different Sterilants, Phenol Binding Agents and Antioxidants on in vitro Establishment of Guava (Psidium guajava L.)

Techniques were standardized for minimizing microbial contamination and leaching of phenols in the media for quick establishment of cultures in guava. The maximum number of aseptic explants with higher survival was obtained by sequential application of ethanol (70%) for 30 second, HgCl2 (0.1%) for 5 minutes, KCl (1%) for one minute and NaOCl (1%) for 8 minutes. The problem of phenolic browning was successfully minimized to a great extent by supplementing MS media with various concentrations of antioxidant and phenol-binding agents. Citric acid at 500 mg/l in the culture medium reduced phenolic exudation the most and promoted the best survival of explants. Initial incubation of cultures under varying levels of light intensity showed escapement up to certain limit from phenolic browning of the me dia. The lowest frequency of browning of media was observed with cultures which were incubated in complete dark for 72 hours; however maximum survival was recorded with 24 hours of dark period