In vitro Organogenesis of Stevia rebaudiana Bert. with Different Explants and Growth Regulators

Resumen

Objective: To evaluate various explants and growth regulators in order to improve in
vitro propagation of Stevia rebaudiana through organogenesis.
Design/Methodology/Approach: Explants and growth regulators in two different
concentrations were evaluated. The explants were nodal segment, axillary bud, and
apical meristem; while the growth regulators were benzylaminopurine (BAP) at 1.125 mg
L -1 and 3.0 mg L -1 , naphthaleneacetic acid (NAA) at 1.5 mg L -1 and 3.0 mg L -1 , and
CIDEF-4 brassinosteroids (BRs) at 1.0 mg L -1 and 1.5 mg L -1 . In total 18 treatments with
seven repetitions. Contamination, oxidation, and survival were recorded during
induction; while leaf number, regrowth height, and root presence were recorded during
multiplication.
Results: At the induction stage there was a differential response between explants
according to their ontogenetic age; during multiplication, the morphological components
showed differences between concentrations of growth regulators and explants, with
higher effectiveness when adding BAP to apical meristems.
Study Limitations/Implications: Both the origin and the age of explants can induce
differential growth while interacting with growth regulators.

Findings/Conclusions: Apical meristem explants showed better advantages for in vitro
reproduction of S. rebaudiana since they present less contamination and higher survival
at the induction stage, even when exhibiting the highest oxidation among explants,
which did not influence the decrease in their survival. At the multiplication stage with
apical meristem, height, leaf number, and root presence were increased. Values were
high when interacting with BAP.