Narcissus and Daffodil

Production of galanthamine in vitro 227
Bulblets
As a consequence of the effect of paclobutrazol, the shoots formed during the
8-week experiment were characterised by the absence of leaves and roots, and
showed an especially well-developed bulb.
Accumulation of alkaloids in the liquid medium
The release of alkaloids into the liquid medium of the explants treated with
paclobutrazol decreased during the experiment (Figure 7.9). Independently of
the paclobutrazol concentration, in all the experiments the main alkaloids released
to the medium were haemanthamine and galanthamine, whose levels reached maximum
values of 71.3 and 35.8 µg/g FW, respectively. Tazettine was not excreted
into the liquid medium in the last sample. The treatment that promoted the highest
release of alkaloids to the medium was 5 mg/l of paclobutrazol.
µg/g FW
µg/g FW
30
25
20
15
10
5
0
80
70
60
50
40
30
20
10
0
N-formylnorgalanthamine
2 4 6 8
Time (weeks)
0mg/l 1mg/l 3mg/l
5mg/l 10mg/l
Haemanthamine
2 4 6 8
Time (weeks)
0mg/l 1mg/l 3mg/l
5mg/l 10mg/l
µg/g FW
µg/g FW
45
40
35
30
25
20
15
10
5
0
25
20
15
10
5
0
Galanthamine
2 4 6 8
Time (weeks)
0mg/l 1mg/l 3mg/l
5mg/l 10mg/l
Tazettine
2 4 6 8
Time (weeks)
0mg/l 1mg/l 3mg/l
5mg/l 10mg/l
Figure 7.9 Levels of alkaloids released by bulblets treated with paclobutrazol into the culture
medium throughout the experiment (bars represent the SD calculated
from three replicates).