Germinação ex vitro e potencial organogênico e embriogênico in vitro de Lecythis pisonis cambess

• Autor(a) principal: Paulucio, Márcia Cristina
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/7692
• topic: Propagation; Vitro culture; Germination; Embryogenic; Rizogenesis; Sapucaia; Cultivo in vitro; Embriogênese; Rizogênese; Recursos Florestais e Engenharia Florestal; Propagação; Germinação; Fertilização in vitro; 630

The species Lecythis pisonis cambess belonging to Lecythidaceae, has ornamental, fruit, timber potential and can be used in reforestation, as well as producing tasty nuts rich in protein and minerals. Studies of propagation techniques sexual and asexual forest species play an important role in scientific research, aiming at the preservation and use of these species with diversified interests. The objective of this study was to evaluate the ex vitro germination of seeds subjected to different methods of scarification and evaluate the in vitro establishment and organogenic potential and embryogenic the species L. pisonis. Initially for ex vitro germination of the study evaluated the length, width and thickness of seeds. Then the seeds were submitted to the following pre-germination treatments: intact seeds (control); mechanical scarification; chemical scarification with sulfuric acid (98%) for 30, 60 and 90 minutes and complete removal of the seed coat. Were evaluated, the emergence percentage (E%); emergence speed index (EVI) and relative frequency of emergency (Fr). The intact seeds and immersed to H2SO4 for 30, 60 and 90 minutes were radiographed by X-ray equipment (X QDP-01X) and analyzed the chemical wear caused by H2SO4 in the seed coat and this treatment caused some damage to the seed. At the end of the experiment was carried out the morphological characterization of seedlings and calculated the percentage of polyembryony seeds scarified mechanically. It was observed that L. pisonis seeds have integumentary dormancy and the most effective treatment to overcome this dormancy was mechanical scarification, with a higher percentage of emergence and vigor of seedlings formed. The x-ray pattern showed that the chemical scarification caused no damage to the seed endosperm and embryo, furthermore, the chemical desgate the integument was proportional to the time of immersion of seeds in sulfuric acid. The seeds of L. pisonis presented 25% polyembryony. Also evaluated the in vitro establishment and the organogenic and embryogenic potential of the species under 9 study. The explants used to establish in vitro were no seed tegument L. pisonis, which were inoculated in WPM medium without growth regulators and maintained in growth room for 150 days. In this experiment were observed different morphogenic responses: Greening (63%), callus formation (84%), germination (8%), direct rizogenesis (4%) and indirect organogenesis (2%). For the induction of somatic embryogenesis were used segments sapucaia inoculated onto MS medium with the addition of growth regulators at different concentrations (0; 1,5, and 3,0 mg L-1 2,4-D), and cytokinin (0, 0,5 and 1,0 m L-1 KI). It was observed that these concentrations were not efficient for induction of somatic embryos. In vitro rooting induction of stem segments seedlings germinated in vitro were tested different concentrations of IBA (0,0;1,0; 2,0 and 3,0 mg L-1). We observed the formation of roots at all concentrations used except in the absence of auxin.