Liquid Culture Systems for in vitro Plant Propagation

Simple bioreactors for mass propagation 89
Growth Value (%)
500
400
300
200
100
0
c
b
b
0 0.75 1 1.25 1.5
Paclobutrazol (ppm)
Figure 4: Clusters growth of Spathiphyllum after subculture to a medium lacking
paclobutrazol following a pretreatment with the growth retardant.
Number of Plantlets per Cluster
16
14
12
10
8
6
4
2
0
a
a
b
b
b
0 0,75 1 1,25 1,5
b
Paclobutrazol (ppm)
Plantlets > 1 cm Plantlets 0.5-1 cm
Figure 5: Shoot and bud growth of Spathiphyllum clusters in paclobutrazol – free medium
after a pre-treatment with the growth retardant.
2.6 Shearing and oxidative stress
In many plants cultivated in bioreactors, the continuous aeration, mixing
and circulation cause shearing damage and cell wall breakdown. The cell
debris adheres to the vessel and causes foaming that prevents adequate liquid
circulation and oxygen supply. Foaming was reduced when ½-strength MS
c
b
b
a
bc
b