Estudo histoquímico da substância de reserva da organogênese direta in vitro de jacaranda ulei bureau & k. Schum in mart. (bignoniaceae)

Abstract

The Jacaranda ulei Bureau & K. Schum in Mart. is native specie from Cerrado. It is used in folk medicine and with great ornamental potential. This study sought to identify the energy source through a histochemical study of the initial phase of direct organogenesis during the development of meristenoids of Jacaranda ulei Bureau & Schum. In Mart. The roots explants were obtained from seedlings from seeds of native plants of the Cerrado, germinated in vitro. The basic medium employed consists of salt ¼ MS (Murashige & Skoog, 1962) plus 20g of sucrose, 6g of agar, 100mg of AIA and 100mg of BAP. O pH was adjusted from 5.7 to 5.8 and the medium was autoclaved at 120ºC for 2o minutes. For the histochemical study, transverse sections were made form root explants in histological resin and paraffin, then subjecting them to Lugol regent. The analysis found that the hypertrophied cortical parenchyma cells are very vacuolated, and showed the presence of many starch granules during the direct organogenesis in the vicinity. In the formation of buds, the meristenoid cells showed dense cytoplasm, large nuclei and some starch.