AN APPROVED PROTOCOL FOR Cynara scolymus and Momordica charantia SEED SURFACE STERILIZATION FOR PRE-EXPLANT in-vitro CULTURE USING Allium EXTRACT

Globe artichoke (Cynara scolymus L.) and bitter gourd (Momordica charantia L.) are two important vegetables being used as food sources of antioxidants for humans. As sexual propagation produces high level heterogeneity, plant tissue culture techniques can be employed for clonal propagation of disease-free germplasm of the species whose vegetative propagation is not guaranteed. Seed and tissue surface sterilization is a critical stage in establishment of aseptic in vitro cultures.
The surface sterilization process must be carried out on explants from field or green house, before tissue culturing. Artichoke seeds are highly sensitive to commonly used sterilization compounds. Low concentrations of disinfectants do not control contamination, and high concentrations over a prolonged time dramatically decrease germination rate. In the present study, an efficient sterilization procedure was developed for artichoke seeds. We compared the two most common disinfectants (sodium hypochlorite, mercuric chloride) with a commercial phytochemical extract, VEG’LYS, at various concentrations and durations of treatment. Treated artichoke seeds were cultured on half basal MS medium for four weeks. VEG’LYS treatment resulted in high germination rate with reduced microbial contamination compared to sodium hypochlorite and mercuric chloride. Results were further extended by using 0.1% VEG’LYS or 10% and 20% sodium hypochlorite, respectively, to surface sterilize bitter gourd seeds. VEG’LYS performed better on both sterilization and germination of seeds compared with sodium hypochlorite. Therefore, VEG’LYS can be used for surface sterilization without inhibitory effect on germination of globe artichoke and bitter gourd seeds.