Explants were pre-treated with 0.1% (w/v) each of streptomycin (antibiotic) and bavistin (a systemic fungicide; BASF Ltd., India) for 15–17 min followed by 6–8 times washing with sterile water. Explants were surface sterilized with 0.1% (w/v) HgCl2 (disinfectant, Hi-Media, India) for 5–7 min washing with sterile water 6–8 times.