Organogênese in vitro em feijão guandu (Cajanus cajan (L.) Millsp.)

• Ano de defesa: 2009
• Autor(a) principal: Andrade, Ana Paula de Souza
• Orientador(a): Brommonschenkel, Sérgio Hermínio
• Banca de defesa: Ventrella, Marília Contin , Carneiro, José Eustáquio de Souza
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Genética e Melhoramento
• Departamento: Genética animal; Genética molecular e de microrganismos; Genética quantitativa; Genética vegetal; Me
• País: BR
• Palavras-chave em Português: Organogênese; Feijão guandu
• Palavras-chave em Inglês: Organogenesis; Pigeon pea
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::MELHORAMENTO VEGETAL
• Link de acesso: http://locus.ufv.br/handle/123456789/4709

The present study was carried out to evaluate the effects of the growth regulators BAP and TDZ on the induction of adventicious shoots of the pigeon pea (cultivars "Anão" and "Fava Larga"). So, zygotic embryos and epicotyledonary segments from in vitro-germinated plantlets were used. In the shoot induction from embryonic axes, the following variables were evaluated at the end of 30 days under culture: the percent callus, the number of roots and shoots formed at both ends (proximal and distal), as well as the presence of contamination and explants without response. The formation of roots were restricted to the explants cultured in the MSØ medium and at the proximal end. In the explants cultured in the MS medium added with cytokinins, an intensive callus formation was generally observed at the proximal end. In both cultivars, the culture medium supplemented with combination of BAP and TDZ at concentrations 4.44μM and 2.27μM respectively, made possible the formation of higher shoot numbers by explant at distal end, but they were reducedsized shoots. Although the lower number of shoots in the explants cultured in mediums added with only BAP (2.22μM) or TDZ (2.27μM), they showed more expanded leaves and vigorous aspect. In shoot induction from the epicotyl segments aseptically obtained from plantlets aged 7 days, the number of roots and shoots formed at both ends were evaluated on the 32o day. The intensity, coloration and texture of the callus were visually evaluated and generally described. Again, the root formations were observed at the basal end of the explants cultured in MSØ medium, whereas a higher number of root formation by explant were observed, compared to the control medium without AgNO3. In both cultivars and both ends of the explants, the medium added with combination of two cytokinins (2.22μM BAP and 2.27μM TDZ) made possible the formation of callus that were visually higher, but at the presence of AgNO3 occurred lower callus formation. The shoot were restricted to basal end of the explants cultured in the medium added with cytokinins and AgNO3, and this combination made possible the formation of higher shoot number. Histological sections revealed the adventicious origin of the shoots via direct organogenesis in the embryonic explants, as well as indirect via in the epicotyl explants. According to the results, the following conclusions were drawn: the use of the embryonic axis, epicotyl segments and both BAP and TDZ cytokinins in inducing the adventicious shoots of the pigeon pea (cultivars "Anão" and "Fava Larga") is promising; the use of AgNO3 is necessary to induce the shoots from the epicotyl segments; and although the addition of precursors and the measurement of the ethylene levels have not been accomplished, the responses obtained in this study may be related to the effect of this hormone. Those data will be useful as base for the accomplishment of complementary studies that are targeted to the improvement of the efficiency in the in vitro regeneration of the pigeon pea, as well as the ex vitro elongation and acclimatization phases.