- ORCHID BIOTECHNOLOGY 193
of the PLBs. Park et al. (2002b) tested few media, such as Murashige
and Skoog (MS), Vacin and Went (VW), Knudson (KC), Lindemann (LM;
Lindemann et al. 1970) and a modified Hyponex (Kano 1965) for pro-
liferation and differentiation of PLBs in variousPhalaenopsishybrids.
Explants had higher survival percentage in Hyponex (75%), MS (62%),
and VW (62%) media, and poor results were recorded for LM (25%)
and KC (20%) media. Higher multiplication (mean number) of PLBs
was observed in MS (18.0), Hyponex (17.4), and VW (13.4), but again
with poor results for KC (4.4) and LM (3.2).
In contrast to semi-solid media, liquid media may offer some advan-
tages in plant development inin vitrosystems, such as higher rates of
proliferation, better control of plant growth and development, and the
potential of reduction in manipulation and labor costs through automa-
tion (Ziv 2000). In addition, liquid cultures can provide more uni-
form culture conditions, easy media renewal, use of larger containers,
and reduced transfer times (Etienne and Berthouly 2002). Tanaka and
Sakanishi (1980) used solid and liquid media cultures for proliferation
of PLBs and found that solid media cultures had yielded better results
than liquid cultures. In contrast and more recently, Young et al. (2000)
reported that VW liquid medium was the most suitable for PLBs multi-
plication, which showed 30% PLB multiplication inPhalaenopsis.
More advanced studies have evaluated growth models forin vitro
plantlets ofPhalaenopsisSogo Yukidian “V3” to determine the optimal
microclimate conditions, including light irradiance, and light and dark
temperatures (Chen 2015). Such studies can assist in the optimization
of automatedin vitrosystems for the large-scale commercial microprop-
agation of orchids. Despite the extensive exploitation of micropropaga-
tion techniques for rapid and large-scale production of orchids, it is
very likely that new, more efficient, economic and enhanced protocols
will be developed for many different species, as well as new hybrids
of commercial value. This should further contribute to the expansion
of the orchid market worldwide and the continued increase in orchid
popularity, accessibility, and demand.
III. Bioreactor Technology
A. Concept
Bioreactor technology involves thein vitroculture of cells, tissues,
and organs in liquid suspension in an automated system. The automa-
tion of micropropagation systems using bioreactors allow significant