Estabelecimento in vitro de Ceiba rubriflora Carv.-Sobr. e L. P. Queiroz: uma espécie endêmica do vale do rio São Francisco

Ceiba rubriflora is a native Brazilian species, critically endangered, from region of middle Sao Francisco River. C. rubriflora's seed production is scarce because of its endemism. Therefore, the micropropagation is presented as a tool for its propagation and seedling production. Thus, the aim of the present study was to evaluate the in vitro establishment of C. rubriflora seeds after disinfestation with different concentrations of active chlorine and testing the in vitro multiplication of apical shoots in different concentrations of 6-benzylaminopurine (BAP). The in vitro establishment of seeds was performed in MS culture medium, which were previously submitted to sodium hypochlorite (NaOCl) disinfection at concentrations of 0.0; 0.5; 1.0; 1.5; and 2.5% active chlorine. Apical shoots of in vitro germinated seedlings were used as explants for multiplication, in MS culture medium, supplemented with BAP in concentrations of 0.0; 1.0 and 2.0 mg L-1. The evaluations were related to seedling survival, fungal and bacterial contamination and number of shoots per explant. The in vitro germination of seeds was satisfactory, with survival rate higher than 98%. The percentage of in vitro contamination was only 2%, free from bacterial cultures. The apical shoots of C. rubriflora were not multiplied in a single subculture in vitro in BAP culture medium. The results demonstrate the viability of in vitro germination of C. rubriflora seeds for the introduction and subsequent micropropagation process, opening perspectives for further studies with the species.