Esterilização química como alternativa à autoclavagem no cultivo in vitro de batata (Solanum tuberosum L.)

Abstract

Micropropagation of plants has several applications of agronomic importance, such as seedling production, high quality sanitary and genetically identical to mother plant. Through the isolation of plant meristems is obtained that is uniform and mostly free of viruses. In the case of cultivation under aseptic conditions, the activities of the seedling production through micropropagation require high quantity of equipment and utensils that need to be sterilized by means of autoclaving process using an autoclave (equipment that produces dry or humid heat and a pressure of 1.05 kg/cm², 121 o C), which requires time and costs. It is a costly process due to the high consumption of energy and water also can cause the decomposition of components of the culture medium, for example, sucrose and change the pH. The objective of this study was to evaluate the efficiency of sodium hypochlorite to control contamination in vitro cultivation of the potato, added together to the culture medium. 3 treatments were performed using NaOCl (sodium hypochlorite) in the culture medium in different concentrations (0.001%, 0.003% and 0.005%), control (without autoclave) and culture media autoclaved, totalizing five treatments. After 30 days into the experiment it was observed that treatment with the control and the autoclaved medium obtained 5% and 10% of explants killed.While treatment with concentration of 0.001% obtained a lower percentage of killed explants 15%. Since the treatments with 0.003% and 0.005% NaOCl had respectively 20% and 30% of explants killed. In all the treatments the explants presented good development of roots and aerial part. There was observed the presence of contamination by fungus, bacteria or oxidation. Finally it was observed that the use of sodium hypochlorite can be an alternative for sterilization of culture medium, but new studies should be performed to confirm the use of this technique.