An Overview: Effect of Plant Growth Regulatory on Orchid Propagation through The Thin Cell Layer technique

Abstract

Thin cell layer (TCL) is a micropropagation method using thin-sized explants. A TCL can be prepared from any explant source and the thichness of explant less than 5 mm. TCL is more efficient in producing total plantlet output than conventional in vitro methods. TCL have been applied to the in vitro culture of orchids, field, vegetable crops and medicinal plants The successful in vitro orchid propagation is influenced by many factors, such as plant genotype and media composition. Additions of plant growth regulator (PGR) in media culture is essential factor. The formation of complete plant depent on concentration and type of plant growth regulator. TCL explants require growth regulators to form an embryonic callus and zygotic embryos. Explant in medium without supplemented of growth regulators resulted in browning and failed to grow. The most commonly plant growth regulator in tissue culture are thidiazuron (TDZ), 6-benzylaminopurine (BAP) 2,4 dichlorophenoxyacetic acid (2,4-D), α-naphthaleneacetic acid (NAA), and meta-Topolin. Recently, microalgae can also be used as an alternative source of hormones to increase plant growth through in vitro culture techniques