Efeito de reguladores de crescimento na embriogênese somática de cana-de-açúcar

• Ano de defesa: 2011
• Autor(a) principal: Ramos, Rachel Soares
• Orientador(a): Barbosa, Marcio Henrique Pereira
• Banca de defesa: Otoni, Wagner Campos , Dias, José Maria Moreira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Fitotecnia
• Departamento: Plantas daninhas, Alelopatia, Herbicidas e Resíduos; Fisiologia de culturas; Manejo pós-colheita de
• País: BR
• Palavras-chave em Português: Cana-de-açúcar; Embriogênese somática; Tecidos (anatomia e fisiologia); Microscopia
• Palavras-chave em Inglês: Sugarcane; Somatic embryogenesis; Tissue (anatomy and physiology); Microscopy
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA
• Link de acesso: http://locus.ufv.br/handle/123456789/4549

Somatic embryogenesis is the process of development of embryos from somatic cells. The aim of this study was to evaluate the efficiency of growth regulators at different stages of somatic embryogenesis of three cultivars of sugarcane, RB 867515, RB928064 e RB925345, and characterize the effects of in vitro treatments of the anatomical development of somatic embryos. Embryogenic calluses were obtained after inoculation of immature leaves arising from lateral buds on MS medium plus 30g.L sucrose, 2.5 g.L agar and different concentrations of 2,4-D, Dicamba and CPA (5,10,15 and 20 mM). After 30 days of induction it showed that the dose of 20μM 2, 4-D was the concentration that induced the highest percentage of callus, 36.95%, and callus were compact and whitish. The calluses were subcultured in the same medium for 30 days and after this period, the callus were transferred to medium with low concentration of 2,4-D (0.5 mg.L-1) to obtain globular pro-embryos. The globular pro-embryos were transferred to multiplication medium and after 30 days were transferred to maturation medium. osmotic regulators were tested, mannitol and sucrose (30, 60 and 90 gL) and ABA (0 and 5 mM). The embryos were transferred to regeneration medium containing 1 mg. L-1 BAP and GA3. The embryos that were in the medium with 30g. L-1, with ABA when transferred to regeneration medium formed healthy and vigorous plants. The histochemical Blue Evans test and Carmine Acetic confirmed the embryogenic of the material. The anatomical study of the process of somatic embryogenesis in leaf explants of sugar cane showed the emergence of callus from the epidermis, which in more advanced stages (globular embryos) easily detached from the explant. It was evident the presence of a well-defined protoderms, isodiametric cells with prominent nuclei and nucleoli and high nucleus / cytoplasm ratio. In the later stages were observed the basal and apical meristem well defined, bounded by a protoderm and immersed in a mass of vacuolated cells, assuming one is in the process of somatic embryo formation. At the end of 30 days in maturation, it was observed a bipolar structure, consisting of stem and root apices, which had a closed vascular system, without connection to the adjacent tissue, confirming the presence of the somatic embryo.