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shoot multiplication, and showing increased growth and plantlet pro-
duction. Fari et al. (2006) reported the application of a revert rotary ́
bioreactor for orchids, although no details on species or even genera
were presented. A balloon type bubble bioreactor (BTBB) was used
to mass propagateAnoectochilus formosanus, an endangered orchid
(Wu et al. 2007). Plant growth was higher under continuous immer-
sion bioreactors. Yang et al. (2010) reported the utilization of a low-cost
bioreactor system for micropropagation ofOncidesaSweet Sugar. More
recently,Cattleya walkerianawas cultivated in a temporary immersion
bioreactor, resulting in plantlets with bigger shoot and root growth,
larger dry weight, and less water loss when compared to conventional
systems (Moreira et al. 2013).
As technology advances, we should expect the application of bioreac-
tors to become the standard inin vitropropagation systems rather than
the exception. Ongoing studies in addition to published research should
elucidate aspects related to the control of the microclimate in automated
bioreactor systems; therefore improving the system and allowing for
more efficient and cost-effective large-scale production at the commer-
cial level. Successful commercial application of bioreactors has been
reported for several species already (Ziv 2000) and for orchids it should
be just a matter of time.
IV. Synthetic Seed Technology (Synseed)
A. Concept
Synthetic seeds (synseeds) were first proposed by Murashige (1978)
and have since become an emergent field in plant cell and tissue cul-
ture research (Standardi and Piccioni 1998). Initially, synseeds con-
sisted of propagules produced only from alginate encapsulated somatic
embryos/PLBs originating from rapidly multiplying vegetative cell cul-
tures (Murashige 1978; Standardi and Piccioni 1998). However, the
technology has expanded to include propagules such as shoots, cell
aggregates, nodes, and any other totipotent (potential to develop into
any cell or tissue type or whole organism) tissue (Standardi and Piccioni
1998). The use ofin-vitro-derived axillary buds and shoot tips provides
inexpensive, easily obtained propagules for storage (Danso and Ford-
Lloyd 2003). Nodal segments of eggplant (Huda et al. 2007) and potato
(Sarkar and Naik 1998, both relatives of tomato as well as difficult-
to-propagate species, such as certain orchids (Saiprasad and Polisetty
2003) have been successfully used to produce synseeds.