Narcissus and Daffodil

238 C. Codina
mg/g DW
mg/g DW
1.5
1.0
0.5
0.0
1.5
1.0
0.5
0.0
The maximum concentration of alkaloids in both sizes of flasks was observed in
the first subculture. This could be due to the fact that the explants have to adapt to
new environmental conditions at an early stage, when transferred from a solid
medium with growth regulators to a liquid one without phytohormones and with
a higher than normal concentration of sucrose. This stressful situation could be
responsible for a higher synthesis of alkaloids.
In general, the accumulation of alkaloids was higher in 250 ml than 500 ml
flasks, although the maximum levels were similar in both vessels. From a morphological
point of view, the plantlets obtained at the end of the experiment appeared
similar, although the leaf development of the explants cultured in 500 ml flasks
was slightly poorer. As the shaking speed was the same in both cases, the larger
flasks had more atmospheric oxygen and, therefore, better aerated plantlets, producing
bulblets that were less stressed and with lower levels of alkaloids.
CONCLUSIONS
N-formylnorgalanthamine
0 2 4 6 8
Time (weeks)
Haemanthamine
0 2 4 6 8
Time (weeks)
500 ml
250 ml
500 ml
250 ml
The culture of shoot-clumps of Narcissus confusus in liquid medium has been found
to be a good experimental system for the production of galanthamine and related
alkaloids. The culture of this kind of explant is improved by the addition of the
cytokinins BA or kinetin at low concentrations (1–3 mg/l). The accumulation of
galanthamine in tissues is higher in shoot-clumps treated with BA, whereas its
release into the culture medium takes place more when kinetin is present. Another
growth regulator, paclobutrazol, affected the two kinds of explants (bulblets and
mg/g DW mg/g DW
1.5
1.0
0.5
0.0
1.5
1.0
0.5
0.0
Galanthamine
0 2 4 6 8
Time (weeks)
Tazettine
0 2 4 6 8
Time (weeks)
500 ml
250 ml
500 ml
250 ml
Figure 7.17 Comparison between the total production of alkaloids (detected in the
tissue and released to the liquid medium) by plantlets grown in two different
flask sizes throughout the experiment.