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

An Overview of Orchid Protocorm-Like Bodies: Mass Propagation, Biotechnology, Molecular Aspects, and Breeding

“…Ref. [30] evaluated the induction of PLBs in two commercial hybrids (Ph908-red-painted yellow flowers and RP3-dark red) of Phalaenopsis and reported significant differences in both percentage of PLB leaf segments (45% and 10%, respectively) as in the number of PLBs per leaf segment (25 and 2 PLBs, respectively).…”

“…One of the influential factors in the induction of PLBs that has been widely evaluated is the concentrations and possible combinations of plant growth regulators (PGRs). Based on the current literature, successful induction of PLBs seems to be mainly influenced by cytokinin BA (6-benzyladenine) and cytokinin-like compound TDZ (thidiazuron), and in some cases the combination of these cytokinins with an auxin [30,45] also proved beneficial. Protocols citing the use of cytokinin BA recommend concentrations between 0.5 mg L −1 [78] and 20 mg L −1 [67].…”

“…For the induction of PLBs with the use of TDZ, the recommended concentrations range from 0.25 mg L −1 [30] to 3.0 mg L −1 [72]. With the combined use of cytokinins and auxins, the most commonly used auxin is NAA, which varies in concentration from 0.1 mg L −1 [45,74] to 1.0 mg. L −1 [30,82].…”

“…Ref. [30] used NDM culture medium plus TDZ (0.25 mg L −1 ) and NAA (1.0 mg L −1 ) and observed distinct responses between '908' genotype (45% explants with PLBs and up to 25 PLBs/leaf segment) and 'RP3' genotype (10% explants with PLBs and only 2 PLBs/leaf segment), the latter being highly recalcitrant to the induction and proliferation of PLBs from leaf segments of plants grown in vitro. A study by [59] also noted important differences between the PLBs induction responses between P. amabilis (up to 50% explants with PLBs and 15.6 PLBs/explant) and the commercial cultivar P. nebula (80% explants with PLBs and up to 5.3 PLBs/explant).…”

“…IPR-PLBs in orchids have different applications in the world flower industry. Undoubtedly the one with the largest commercial application is aimed at the mass propagation of clonal plants to meet the world's demanding flower production market, in which orchids play a significant part in both the pot and cut flower market [6,30]. However, other applications such as for species conservation purposes [31] and obtaining transgenic plants [32] can be found in the literature.…”