Standardization of a regeneration protocol in yellow pitahaya (Selenicereus megalanthus (K. Schum. ex Vaupel) Moran)

摘要

A protocol for in vitro regeneration in yellow pitahaya by using indirect organogenesis pathway was standardized from axillary meristem grown on MS medium. The medium was supplemented with three concentrations of 2,4-D (2.26, 3.26 and 4.26 µM) or 2,4-D + 6- BAP to 2.21 mM, or with three concentrations of TDZ (200, 300 and 400 µM) or TDZ + 6- BAP, a total of 12 treatments. Growing conditions evaluated included the use of light (photoperiod of 16/8) and darkness (0/24). The 2.4-D induced calli but regeneration efficiency for the species was nil. In turn, the TDZ or TDZ + BAP were more efficient in inducing compact calli, green-purple, with capacity of regeneration following indirect organogenesis. With 300µM of TDZ more efficiency of response was observed, because the number of buds formed by regeneration point was the highest. Histological analysis confirmed the route of regeneration in S. megalanthus, showing primary structures characteristic of the formation of shoots from calli.