PLBs induction and clonal plantlet regeneration from leaf segment of commercial hybrids of Phalaenopsis

Induction of Protocorm-like bodies (PLBs) from leaf segments is a clonally propagation technology that used somatic embryogenesis regeneration from in vitro buds of floral stalks, and is a potential alternative for replacement actual low-yield and high-cost clonal propagation of Phalaenopsis orchids. The objective of this work was to evaluate induction of PLBs in leaf segments of two commercial hybrids of Phalaenopsis, arranged in culture media with different combinations of plant growth regulators. The leaf segments (0.4-0.5 cm(2)) used for PLBs inductions were obtained from young in vitro-induced shoots from inflorescence stalks. They are cultivated in NDM culture media, supplemented with combinations of plant growth regulators Naphthaleneacetic Acid, Thidiazuron and Benzyladenine. The flasks were kept for 60-d in darkness and then for cold white light with photon flux density of 35-40 mu mol m(-2) s(-1). The cultivar 'Ph908' showed a higher percentage of leaf segments with PLBs (45%) and number of PLBs (25 per leaf segment), in medium containing 0.25 mg L-1 of TDZ, whereas 'RP3' showed only 10% containing PLBs and 2 PLBs per leaf segment in NDM with 1.0 mg L-1 NAA, 20 mg L-1 BA and 0.125 mg L-1 TDZ.