Effect of photoperiod and plant growth regulators on in vitro mass bulblet proliferation of Narcissus tazzeta L. (Amaryllidaceae), a potential source of galantamine.

Narcissus tazetta L., a bulbous plant belongs to the Amaryllidaceae family, contains alkaloid galantamine (GAL) with acetylcholinesterase inhibitory activity which has been recently considered to treat Alzheimer's disease (AD). In the current work, the effect of photoperiod (16/8 h light/dark and 24 h dark) and various concentrations of NAA, BAP, and GA3 (0, 0.5, 1 and 2 mg l‒1) on the in vitro mass bulblet regeneration of N. tazetta was studied. The GAL production ability of the regenerated bulblets was assessed by HPLC-UV-MS. Light treatments significantly affected the number of bulblet and leaf, the ratio of bulblet/leaf, and leaf length. The maximum number of bulblet (31.0 ± 1.58) and leaf (13.3 ± 1.33) was recorded from the cultures fortified with NAA and BAP (2 mg l‒1) kept in 16/8 h light/dark, while the maximum leaf length (2.1 ± 0.92 cm) was measured on the MS medium containing 0.5 mg l‒1 NAA and 2 mg l‒1 BAP incubated in the same photoperiod. The average ratio of bulblet proliferation per explant was significantly different between studied photoperiod (1.1 ± 0.86) and 24 h dark (0.62 ± 0.31). The regenerated bulblets contained 40 and 20 µg g‒1 DW GAL underexposed photoperiod and 24 h dark, respectively. This information could be useful in the commercial production of GAL as a valuable anti-AD compound through in vitro mass bulblet proliferation of N. tazetta.