Influence of different sterilization methods on callus initiation and production of pigmented callus in Arnebia densiflora Ledeb.

We analyzed the effects of sodium hypochlorite and Plant Preservative Mixture (PPM) on surface sterilization.We also examined the effects that the addition of an antibiotic-antimycotic solution to the culture medium had on callus induction. Explants were initially sterilized with different concentrations of sodium hypochlorite and cultured on MS media containing kinetin (0.29 μM) and naphthalene acetic acid (NAA, 10 μM). No calluses were produced, either because of contamination of the explants, or loss of explants as a result of the high levels of sodium hypochlorite. The application of PPM and antibiotics at different concentrations reduced contamination and led to callus induction from shoot apexes and young root explants. The best callus responses were obtained using PPM at 1%-2%, whereas callus induction on shoot apexes diminished at higher concentrations (4% PPM). This is the first report of successful sterilization and reduced contamination of explants from naturally field grown A. densiflora by PPM. Moreover, established callus cultures produced pigmented calluses, which were analyzed spectrophotometrically.