Efeito do uso de citocininas no potencial embriogênico e obtenção de protoplastos em calos de Jequitibá-rosa Cariniana legalis (Mart.) O. Kuntze

Abstract

Jequitibá-rosa is a woody species from the Atlantic Forest of high economic and ecological value. With few individuals in the wild, it is currently threatened with extinction according to IUCN. Thus, it is necessary to improve techniques of vegetative propagation of such species, and somatic embryogenesis and culture of protoplasts are promising strategies aimed at such. The first part of the present study sought to investigate the effect of different concentrations of growth regulators of the class of cytokinins BAP (6-benzylaminopurine) and KIN (Cinetina) on the embryogenic potential of Jequitibá-rosa calluses. All treatments underwent cytochemical analysis with Evans blue dyes and acetic carmine in order to identify the presence of cells with embryogenic activity. Within the tested treatments, those that showed the best results for the presence of embryogenic cells were T0 MC and ME: 0.0 mg L -1 BAP + 0.0 mg L -1 KIN, T3 (ME): 10.0 mg L -1 BAP + 0.0 mg L -1 KIN and T4 (B): 10.0 mg L -1 BAP + 3.0 mg L -1 KIN. Such treatments were then submitted to histological analysis which demonstrated that there were no structures related to somatic embryos in any of these treatments, but the presence of substances that resemble the extracellular matrix was identified, making further studies of this nature necessary with the species. The second part of this study aimed to obtain protoplasts through calluses induced by clones from specimens from Paraguaçu, Machado and Divisa Nova. The calluses were induced in WPM 3 mg/L

-1 BAP (6-

benzylaminopurine) and 0.1 mg/L

-1 ANA (Naphthalene Acetic Acid) culture media. For the degradation of the cell wall, the callous cells were submitted to a treatment with enzymatic solution of cellulase, pectinase in mannitol together with the W5 solution. Cell viability tests were carried out by counting cells with Evans blue 1%, with the aid of the Neubauer chamber, and the influence of the W5 solution on the regeneration of protoplasts was tested. It was found that the use of the W5 solution did not generate a difference in obtaining cells, making further studies necessary.