Regeneração in vitro de urucum (Bixa orellana L.) a partir de diferentes tipos de explantes
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2005-08-10
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Revista Árvore
Resumo
Este trabalho teve como objetivo avaliar a regeneração in vitro de plantas de urucum (Bixa orellana L.) a partir de diferentes tipos de explantes. Para definir o meio de cultura adequado para indução de brotações, diferentes concentrações e, ou, combinações da auxina AIA e das citocininas BAP e ZEA foram testadas. As melhores respostas de regeneração para segmentos de hipocótilo, nós cotiledonares e hipocótilos invertidos foram observadas em meios suplementados de ZEA (2,28 µM) e AIA (0,30 µM), ZEA (4,56 µM) e ZEA (4,56 µM), respectivamente. O meio de enraizamento mais eficaz foi o MS, com a metade de sua concentração salina e 5 µM de AIB. Análises citológicas, realizadas antes da aclimatação, confirmaram a estabilidade cromossômica das plantas cultivadas in vitro, não sendo detectado variação com relação ao número de cromossomos metafásicos (2n = 14).
The present work aimed the establishment of a regeneration protocol for annatto (Bixa orellana L.) from different juvenile explants. In order to promote shoot induction, different concentrations and/or combinations of IAA and the cytokinins BAP and ZEA were assessed. Better regeneration responses were achieved when segmented hypocotyl, cotiledonary nodes and inverted hypocotyl were cultured onto MS-based medium supplemented with ZEA (2.28 µM) and IAA (0.30 µM), ZEA (4.56 µM) or ZEA (4.56 µM), respectively. Rooting of elongated shoots displayed higher frequencies when half-strength MS medium with IBA (5 µM) was used. No genetic variation was detected among regenerants as revealed by cytological analysis based on metaphasic chromosome countings (2n = 14).
The present work aimed the establishment of a regeneration protocol for annatto (Bixa orellana L.) from different juvenile explants. In order to promote shoot induction, different concentrations and/or combinations of IAA and the cytokinins BAP and ZEA were assessed. Better regeneration responses were achieved when segmented hypocotyl, cotiledonary nodes and inverted hypocotyl were cultured onto MS-based medium supplemented with ZEA (2.28 µM) and IAA (0.30 µM), ZEA (4.56 µM) or ZEA (4.56 µM), respectively. Rooting of elongated shoots displayed higher frequencies when half-strength MS medium with IBA (5 µM) was used. No genetic variation was detected among regenerants as revealed by cytological analysis based on metaphasic chromosome countings (2n = 14).
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Propagação in vitro, Organogênese, Urucum, Cultura de tecidos