Acta Botanica Brasilica
versión impresa ISSN 0102-3306
ITAYA, Nair Massumi; VAZ, Ana Paula Artimonte; KERBAUY, Gilberto B. y FIGUEIREDO-RIBEIRO, Rita de Cássia L.. Fructan production in callus and in vitro cloned seedlings of Viguiera discolor Baker (Asteraceae). Acta Bot. Bras. [online]. 2005, vol.19, n.3, pp. 579-586. ISSN 0102-3306. http://dx.doi.org/10.1590/S0102-33062005000300019.
Viguiera discolor Baker is a herbaceous species, native to cerrado and its survival has been threatened by the invasion of exotic species. Considering its high production and the wide application of fructans, the present work has aimed to establish in vitro culture of this species and to investigate the presence of fructans under these conditions. Seeds were germinated in vitro on modified MS medium and after plant growth, stem nodes were isolated and incubated on the previous culture medium, supplemented with 0.5 mg L-1 NAA, which allowed the production of uniform plants, and formation of non thickened roots, tuberous roots and callus-like structures (callus type 1). Analysis of these materials showed the presence of inulin-type fructans. Incubation of stem nodes in the presence of 2,4-D induced growth of friable callus (callus type 2), in which fructans and their synthesis enzymes sucrose: sucrose 1-fructosyltransferase (SST) and fructan: fructan 1fructosyltransferase (FFT) were detected. Although in lower concentrations, the ratio SST/FFT activities and their fructans were similar to values found in plants cultivated under natural conditions. Stem nodes incubation on hormone-free medium resulted in regeneration of 50% plantlets. In vitro propagation, of V. discolor, may allow large-scale multiplication and conservation of this species, as well as fructan production under this condition.
Palabras llave : cerrado; inulin; reserve carbohydrates; tuberous roots.