Narcissus and Daffodil

Production of galanthamine in vitro 231
Table 7.5 Total production of alkaloids (accumulation in both tissue and liquid
medium) in shoot-clumps grown under different concentrations of
paclobutrazol (µg/g FW ± SD calculated from three replicates) a
Paclobutrazol NFNGAL GAL HAEM TAZ
0 mg/l 298.7 ± 12.4 329.4 ± 77.1 418.4 ± 43.4 149.2 ± 24.1
1 mg/l 159.5 ± 31.2 208.4 ± 72.4 177.9 ± 33.4 81.1 ± 15.0
3 mg/l 198.3 ± 17.1 268.4 ± 102.2 231.8 ± 16.2 109.9 ± 3.4
5 mg/l 208.6 ± 6.6 307.4 ± 108.7 243.5 ± 106.1 119.2 ± 4.6
10 mg/l 320.5 ± 25.0 465.1 ± 221.1 346.0 ± 60.2 177.4 ± 3.8
Note
a for abbreviations, see Table 7.1.
Total production of alkaloids during the experiment
The total production of alkaloids in the shoot-clumps treated with 1, 3 or 5 mg/l of
paclobutrazol was lower than in the controls (Table 7.5). Nevertheless, the highest
production took place in those treated with 10 mg/l of paclobutrazol. Galanthamine
was the main alkaloid produced under the influence of paclobutrazol,
whereas the control shoot-clumps accumulated mainly haemanthamine.
By comparing the effect of paclobutrazol on both the morphology of the
explants and the production of alkaloids, one can observe that the bulblets were
better developed than the shoot-clumps, as the latter became necrotic. In general,
growth was higher in the explants (bulblets and shoot-clumps) treated with
paclobutrazol, as was also observed in Gladiolus (Ziv, 1992), although the differences
among the different treatments were small. In both kinds of explants, the presence
of paclobutrazol in the medium, promoted the development of adventitious
shoots and, in general, inhibited the synthesis of alkaloids in comparison with the
control explants. The excretion of alkaloids into the liquid medium was higher in
shoot-clumps than in bulblets.
EFFECT OF SUCROSE CONCENTRATION ON GROWTH
AND PRODUCTION OF ALKALOIDS
The importance of sucrose, a source of carbon essential for the growth and development
of bulbs, has previously been demonstrated in plants belonging to the
genera Allium (Keller, 1993), Lilium (Takayama and Misawa, 1979), Tulipa (Taeb
and Alderson, 1990), Narcissus (Chow et al., 1992) and Gladiolus (Steinitz et al.,
1991). With the exception of Gladiolus, these experiments were carried out in solid
agar media. The present experiments were performed in liquid medium with
shoot-clumps derived from both bulbs and seeds of Narcissus confusus, which were
treated with different concentrations of sucrose, 30, 60, 90, 120, 150 and 180 g/l
(Sellés et al., 1997b). The experiment took place over two weeks, as the secondary
metabolites are usually formed at the end of the growth period, when the nutrients
of the medium become limiting.