Criopreservação e produção de sementes sintéticas in vitro de mangabeira / Cryopreservation and in vitro synthetic seed production of mangabeira

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

23/02/2010

RESUMO

The mangabeira is a medicinal and fruit species of the Brazilian Cerrado that presents propagation difficulties through seeds, due, mainly to the low germination rate and recalcitrance. Furthermore, it undergoes an accelerated genetic erosion process as a consequence of the extractivist exploitation. As a result, the development of alternative methodologies for the in vitro conservation of the species becomes relevant. The aim of this work was to study the cryopreservation aspects and synthetic seeds production of mangabeira, starting from in vitro obtained explants. As a result for the growth and the cellular viability of the mangabeira friable calli, a significant difference was observed among the cryoprotectant solutions used in the pre-treatment of these calli. The vitrification solutions PVS2 and modified PVS2 inhibited the calli growth and reduced their viability by at least 80%. Calli exposed to the solution B (8% DMSO + 0.4M sucrose) were those which presented better results related to the cellular viability (110%) and fresh matter increase (45%). For the cryopreservation, the tetrazolium test was shown efficient in the determination of the mangabeira calli viability. A viability reduction was observed between the 10th and 30th day of cultivation. Through the ultra-structural analysis it was possible to observe the presence of plasmolyzed and broken cells besides a high accumulation of the cryoprotectant solutions. Related to the production of synthetic seeds originated from apical buds, the optimum salt constitution associated to the sodium alginate matrix was determined as well as their storage at different temperatures. For the regeneration of the apical buds it was verified that the higher levels of available salts in the culture medium, the less the need of salts associated to the encapsulation matrix. At 45 days of cultivation, the regeneration rate was 70% and the length of the shoots presented an average of 2.25 cm. For the storage, the highest tolerance of the synthetic seeds was observed at the temperature of 4 C when sucrose was added (1 and 3%) to the sodium alginate matrix, reaching an average of 60% regeneration.

ASSUNTO(S)

hancornia speciosa crioprotetor viabilidade celular microscopia eletrônica unidade encapsulável fitotecnia hancornia speciosa cryoprotectant cell viability electronmicroscopy encapsulable unit

ACESSO AO ARTIGO

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