Propagação vegetativa e cultivo in vitro de Bixa orellana L. e Ginkgo biloba L.

• Autor(a) principal: Mantovani, Nilton César
• Data de Publicação: 2007
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/383
• topic: Cultura de tecidos; Propagação; Morfogênese in vitro; Bixa orellana; Ginkgo biloba; Tissue culture; Propagation; In vitro morfogenesis; Bixa orellana; Ginkgo biloba; CNPQ::CIENCIAS BIOLOGICAS::BOTANICA::BOTANICA APLICADA

Bixa Orellana L. and Ginkgo biloba L. are woody species that synthesize exclusive medicinal components of economic importance. The objectives of this study were: (1) to evaluate and select genotypes of B. orellana with high bixin content; (2) to rescue vegetative genotypes of B. orellana aiming the production of explants for the in vitro culture; (3) to establish a system of in vitro propagation of B. orellana from axillaries shoots in nodal segments of adult plants, and adventitious shoots from juvenile explants; (4) to induce the formation of calli from leaf explants of G. biloba and to evaluate the in vitro production of secondary metabolites; (5) to establish a system of in vitro propagation of G. biloba from axillaries shoots in nodal segments of adult plants. Genotypes of B. orellana with high bixin content had been rescued by air layering technique and propagated in vitro by the induction and growth of axillaries shoots from nodal segments. The explants were disinfested with of sodium hipochloride solution (10 minutes 1.25%) and PPMTM (20 minutes 20%), and cultivated on MS medium culture. The addition of PPMTM 1%, Timentin® 600 mg.L-1 and 300 Agrimicin® mg.L-1 to the culture medium partially controlled the development of bacteria on the explants. The development of axillaries shoots was observed in 28% of the nodal segments. Adventitious shoots were induced in cotyledon discs, hypocotyl and root segments cultivated on MS and WPM media with ZEA 4.56 µM. It was identified a gradient of morphogenic potential that increase from the apex in direction to the base of the hypocotyls and roots explants. High frequencies of regeneration of shoots were induced in cultivated hypocotyl segments on WPM medium culture with 4.56 µM TDZ (85%) and with 4.56 µM ZEA (80%). The AIB 4.9 µM induced greater frequency of rooted shoots (25%) and roots number (2). Complete plants in vitro produced were transferred to substract and successfully acclimatized in a greenhouse. The histological analysis had proven the adventitious origin of the shoots from the organization of meristematic centers in cortical cells of hypocotyl segments, characterizing direct organogenesis in B. orellana. In G. biloba leaf explants callogenesis is dependent of an exogenous source of auxin. Greater callus frequencies had been induced from leaf discs cultivated on MS medium with ANA 4.4 µM combined with 0.4 BAP µM (100%) or 4.4 µM (92%). The maximum production of callus fresh mass was observed with carbohydrate sucrose (394,57 mg) and the subcultivation in the dark (678,3 mg). The BAP modified the pattern of the primary callus from white yellowish friable to green compact one when used by three subcultivation period. The terpene trilactones ginkgolides A and B, and the flavonol glycosides quercetin, kaempferol and rutin have not been observed in calli cultivated in vitro and in leaves of G. biloba through TLC and HPLC methods. The in vitro propagation of G. biloba was carried out by means of axillary shooting in nodal segments excised from herbaceous branches, harvested from adult plants maintained in greenhouse. The hydrolyzed casein (500 mg.L-1) in MS medium, was essential for the induction of higher frequencies of axillary shoots in nodal segments (85%), for multiplication of these shoots (66.6%), and also for formation of multiple shoots in the explants. The kinetin and the activated charcoal were inhibitory to this process.