178 W. A. VENDRAME AND A. A. KHODDAMZADEH
Aside from mass propagation or production of pathogen-free plants,
biotechnology offers different techniques for conserving orchids. While
synthetic seed (synseed) technology was initially defined as the encap-
sulation of somatic embryos and protocorm-like bodies (PLBs) in
alginate, the technology has been expanded to include shoots, cell
aggregates, nodes and any other totipotent tissues (Standardi and
Piccioni 1998). This technology provides inexpensive and easily
obtained propagules for storage and conservation.In vitrogermplasm
collections are used to preservein vitro-derived orchids, but the pro-
cess is time limited (Vendrame et al. 2014).
Cryopreservation brings an innovative approach providing a long-
term method for the conservation and preservation of orchid mate-
rial, including seeds, protocorms, and pollen. Cryopreservation and
long-term storage of orchid germplasm has been reported and reviewed
previously (Gonzalez-Arnao et al. 2008; Hossain et al. 2013; Teixeira da
Silva 2013; Vendrame et al. 2014).
II.IN VITROPROPAGATION TECHNOLOGY
A. Concept
In vitropropagation of plants is based on the concept of totipotency in
plant tissue culture or the culture of plant cells, tissues, or organs under
aseptic conditions, which allows the regeneration of a fully functional
plant. The utilization of seedlings in asexual propagation requires a long
juvenile period necessary before flowering (Decruse et al. 2003), while
in vitropropagation is more efficient and faster than sexual propagation
and other vegetative procedures and therefore the most popular method
used for the multiplication of orchids (Talukder et al. 2003). The multi-
plication of true-to-type plants viain vitrotechniques is responsible for
the success of the orchid industry (Chugh et al. 2009),
Whereas specialty growers (i.e., breeders for specific genera, such as
Vanda,Cattleya,etc.)mayrelyonin vitroseed germination for gener-
ation of new hybrids and genetic material, large-scale growers are uti-
lizing more advancedin vitrotechniques for the clonal propagation of
orchids. The recent development of bioreactor technology forin vitro
propagation of plants has revolutionized the industry, allowing even
faster and larger-scale production of plants. For this reason and due to
its unique characteristics, we will discuss bioreactor technology as a
separate topic.