Cultivo in vitro e atividade de enzimas envolvidas na oxidação de explantes de Tapeinochilos ananassae (Hassak) K. Schum

Abstract

The in vitro culture is a tool of great importance in the production of seedlings of the fitossanitary quality. The Tapeinochilos ananassae (Hassk) K. Schum is a tropical species that has a great acceptance in the world of floriculture market and presents, in the Brazilian Northeast, fitossanitary problems in which the Rhabdovirus is highlighted. In the present work, aiming to assess the establishment and development of various explants in the in vitro culture of T. ananassae, including the study of biochemical and anatomical variables. For this, lateral buds and mature zygotic embryos were inoculated in MS medium, full or reduced to its half ionic strength, using three sources of antioxidants: ascorbic acid, activated charcoal and PVP, in the concentrations 0,25g.L-1; 3,0g.L-1 and 0,5g. L-1. The ½MS culture medium supplemented with 3,0g. L-1 activated charcoal promoted a higher rate of success in the establishment of zygotic embryos. The plants formed from the culture of embryos were propagated by nodal segments in different concentrations of BAP and GA3: ½MS; ½MS + 0,5mg.L-1 GA3; ½MS + 1,0mg.L-1 GA3; ½MS + 0,5mg.L-1 BAP; ½MS + 0,5mg.L-1 BAP + 0,5mg.L-1 GA3; ½MS + 0,5mg.L-1 BAP + 1,0mg.L-1 GA3; and showed better development when cultivated in ½MS medium free from growth regulators. The lateral buds had not shown morfogenetic development under the conditions of study, besides a large phenolic oxidation had been seen, regardless of the culture medium that had been used, and a high level of microbial contamination, especially bacterial, when buds that had come from basal branches are used. In the enzymatic analysis of lateral buds that were cultivated in vitro in a process of oxidation, had been realized that the activity of peroxidase had declined through the time, suggesting the loss of organogenetic potential, but the activity of polyphenoloxidase had tended to increase during the oxidation process of explants.