Liquid Culture Systems for in vitro Plant Propagation

Mass propagation of tropical crops 203
Semisolid
medium
Static liquid
medium
Plantlets
Acclimatization
Donor plant
Culture initiation
Shoot multiplication
(semisolid or liquid medium)
TIS
multiplication
TIS
Elongation/rooting
TIS
Formation of
Storage organs
Direct transplant
Figure 2: Scheme of TIS integration in plant propagation via organogenesis.
Another interesting option is the formation of storage organs like
microtubers or microbulbs, since they can be afterwards directly transplanted
in the greenhouse or field without acclimatization.
For the application of TIS for somatic embryo production a number of
options are amenable for use (Figure 3). As in organogenic propagation, a
first standard step for culture initiation and somatic embryo induction is
necessary, either in semisolid medium or in liquid cell suspension culture.
From that point two possibilities arise, the first is the multiplication of
somatic embryos by secondary embryogenesis in TIS followed by embryo
germination in semisolid medium or in TIS (Escalant et al., 1994; Etienne et
al., 1997; Cabasson et al., 1997; Berthouly and Etienne, 1999; Akula et al.,
2001; Vilches et al., 2002). The second possibility is the use of bioreactors for
scaling up the mass production of somatic embryos and the combination with
TIS for embryo germination and plant development. This option is not fully