The Effect of Ascorbic and Citric Acids in the in Vitro Establishment of Solanum betaceum to Prevent Phenolic Oxidation

Tamarillo (Solanum betaceum) is an Andean woody plant. Due to the chemical composition and high-nutritional value of its fruits, it is considered a viable option for research and mass production through plant tissue culture. This species is susceptible to phenolic oxidation caused by mechanical damage such as cuts made to obtain axillary buds as explants. In order to solve this problem, explants were cut and added into a solution of citric acid and ascorbic acid at a concentration of 100 ppm, respectively; subsequently, the disinfection protocol was conducted to avoid contamination in the phase of in vitro establishment. This research aims to analyze the response of axillary buds and seeds. Phenolic oxidation, plantlet regeneration, number and coloration of leaves, as well as callus induction, were evaluated. Axillary buds showed 8% of phenolic oxidation, while seeds did not present any. The highest plantlet regeneration (68.42%), leaf coloration (3/5) and number of leaves (3.26) were obtained by axillary buds. The phenolic oxidation showed by buds (8%) was very low compared to previous literature.