Metabolism of Epidendrum fulgens during rooting and ex-vitro acclimatization


The culture media composition during the in vitro rooting phase is directly related to the success of acclimatization. Pre-treatments using low carbohydrate and salt concentrations in the rooting medium have stimulated a pre-adaptation to an autotrophic conditions. Epidendrum fulgens plantlets were cultivated, for 60 days, in different salt concentrations of MS and sucrose medium with or without growth regulators, during the rooting phase. This treatment aimed to promote a pre-adaptation to an autotrophic condition during the acclimatization stage. A 50% reduction in the salt concentration of MS medium, added to 1.5% and 3.0% (w/v) sucrose, and a 67% reduction in the salt concentration added to 1.5% sucrose in the culture media, with or without growth regulator, promoted a significant increase in the
plantlets height. However, the same effect was not observed in the root numbers. Plantlet cultivated in the medium where nutrient and sucrose concentrations were reduced, with or without growth regulators, presented a mixotrophic at the end of the 60 day in vitro rooting period and a greater autotrophy of the plantlet at 15 days of acclimatization.