Regeneration of pitaya by indirect organogenesis evaluated by scanning electron microscopy and flow cytometry

Abstract

The objective of this work was to evaluate the induction of indirect organogenesis by concentrations of dichlorophenoxyacetic acid (2,4-D) and thidiazuron (TDZ) in pitaya (Hylocereus undatus) explants, using scanning electron microscopy and the flow cytometry technique. The treatments consisted of the concentrations of 0, 2.0, and 4.0 mg L-1 2,4-D and TDZ and of the combinations of these regulators. Percentages of callus coverage at 45 and 60 days were evaluated. The explants subjected to the treatments were analized by flow cytometry and scanning electron microscopy. All treatments induced endoreduplication, and there was no somaclonal variation. Under the combination of 2.0 mg L-1 TDZ and 4.0 mg L-1 2,4-D, calluses were formed in 95% of the explants, but were smaller than those produced with 2,4-D separately. The concentration of 2.0 mg L-1 TDZ induces the indirect organogenesis in pitaya explants, confirmed by the presence of conducting vessels through scanning electron microscopy.

Pitaya Nutrition, Biology, and Biotechnology: A Review

“…Fan et al [ 191 ] used 442 inter-simple sequence repeat (ISSR) markers, producing 55 primers exhibiting no polymorphism and somaclonal variation after 15 multiplication cycles of shoots; the results were attributed to the existence of high genetic fidelity in H. undatus . Hua et al [ 190 ] and Rodrigues et al [ 200 ] also reported no somaclonal variation after multiple in vitro cycles.…”