<Emphasis Type="Italic">Bridelia stipularis</Emphasis>: a new source for anthocyanin production in vitro

The present study prospects Bridelia stipularis (L.) Blume as a new source of anthocyanins through leaf and internode explants-derived callus cultures. Murashige and Skoog (MS) medium fortified with 21.48 μM α-naphthaleneacetic acid was superior for callus growth. Of the different regimes, the anthocyanin production relied on synergic effects of plant growth regulators, pH, light, and carbon source. The calluses incubated in light on MS medium with 4% glucose containing 2.22 μM N⁶-benzyladenine (BA) and 2.26 μM 2,4-dichlorophenoxyacetic acid (2,4-D) at pH 3.5 yielded the highest amount (a mean of 0.42 mg g⁻¹ callus) of anthocyanins. Subsequent cultures of the calluses on the above medium yielded a stable production of anthocyanins. Medium containing glucose was superior to that with sucrose for anthocyanin formation. Kinetin was inhibitory to anthocyanin accumulation. Suspension cultures of MS medium containing 2.26 μM 2,4-D and 2.22 μM BA at pH 5.0 started excretion of anthocyanins into the medium on reaching to pH 4.4–4.6.