Narcissus and Daffodil

226 C. Codina
Table 7.3 Total production of alkaloids (accumulation in both tissue and liquid
medium) in shoot-clumps grown under different concentrations of
kinetin (µg/g FW ± SD calculated from three replicates) a
Kinetin NFNGAL GAL HAEM TAZ
0 mg/l 274.9 ± 9.5 358.9 ± 26.1 368.9 ± 55.2 139.2 ± 21.9
1 mg/l 209.1 ± 7.2 179.1 ± 15.1 173.0 ± 22.6 147.8 ± 4.3
3 mg/l 144.1 ± 6.6 182.2 ± 13.3 142.9 ± 9.0 208.6 ± 3.9
5mg/l 95.1± 8.8 159.2 ± 19.9 103.4 ± 8.2 39.3 ± 1.9
10 mg/l 98.2 ± 8.3 225.8 ± 37.0 188.7 ± 38.1 32.8 ± 5.2
Note
a for abbreviations, see Table 7.1.
Comparing the effects of these cytokinins on explant development and alkaloid
production, one can observe that shoot-clumps treated with BA showed a better
development than those treated with kinetin. The best treatment for the multiplication
of the explants was the concentration of 3 mg/l of BA, and the controls,
with a lower number of leaves, accumulated a higher amount of dry matter. In
addition, the degree of necrosis in the experiment with kinetin was higher than in
the other experiments, which could be related to a higher release of alkaloids by
the shoot-clumps. In comparison with the control explants, the alkaloid content,
in general, was strongly influenced by the different concentrations of BA, galanthamine
and haemanthamine being the predominant alkaloids produced.
The results of this experiment reveal that Narcissus confusus is not especially
susceptible to vitrification, which is usually found when tissues are cultivated in a
liquid medium and, in addition, under high concentrations of cytokinins (Hussey,
1986). This could be due to the fact that the subcultures were systematically performed
every two weeks, instead of every five weeks as described for other species
of this genus (Chow et al., 1993). This higher frequency of subculturing could have
avoided the excessive accumulation of ethylene inside the culture flasks, which is
also involved in the vitrification process (Hussey, 1986).
Effect of paclobutrazol
Paclobutrazol, an inhibitor of gibberellin biosynthesis, has been used in liquid
cultures with other plants belonging to the genera Gladiolus (Steinitz and Lilien-
Kipnis, 1989), Nerine (Lilien-Kipnis et al., 1992), Colchicum (Ellington, 1998), Solanum
(Simko, 1994), Nephrolepis and Philodendron (Ziv, 1992), and its influence on both
the proliferation of meristematic shoots and the lateral growth of explants has
been observed.
The effect of paclobutrazol has been examined on explants with different levels
of development: bulblets with emerging leaves and well formed bulbs, and shootclumps.
The explants were obtained as previously described (Sellés, 1996), and
cultured in baby-food jars with MS liquid medium supplemented with 6% sucrose
and paclobutrazol at concentrations of 0, 1, 3, 5 and 10 mg/l. They were cultivated
for two months at 25 ± 1 °C under a photoperiod of 16 h, and shaken at 110 rpm.
The concentrations of the alkaloids accumulated in tissue were determined 8 weeks
after starting the experiment, whereas the release of alkaloids to the liquid medium
was measured every two weeks, coinciding with the subculturing steps.