Navegando por Autor "STEIN, Vanessa Cristina"

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Acesso aberto (Open Access)
Efeito de meios de cultura, concentrações de GA3 e pH sobre a germinação in vitro de mangabeira (Hancornia speciosa Gomes)
(2009) SOARES, Fernanda Pereira; PAIVA, Renato; STEIN, Vanessa Cristina; NERY, Fernanda Carlota; HERRERA, Raírys Cravo; OLIVEIRA, Lenaldo Muniz de
The Hancornia speciosa Gomes species presents potential for fruit and rubber production. Propagation is difficult primarily due, to a reduced seed germination and occurrence of recalcitrant seeds that stimulate the search of rapid and efficient propagation alternatives. In this context, the aim of this work was to study in vitro seed germination conditions in order to produce explants to be used on in vitro culture. The effect of different culture media, sucrose and GA3 concentrations and three pH levels were evaluated. Seeds were extracted from mature fruits after being harvested and processed. Higher in vitro germination was obtained using WPM and MS/2 media supplemented with 15.0 g L-1, 0.2 mg L-1 GA3 and pH adjusted to 5.8.
Acesso aberto (Open Access)
Induction and Morpho-Ultrastructural Analysis of Organogenic Calli of a Wild Passionfruit
(2014-12) CARVALHO, Milene Alves de Figueiredo; PAIVA, Renato; STEIN, Vanessa Cristina; HERRERA, Raírys Cravo; PORTO, Jorge Marcelo Padovani; VARGAS, Daiane Peixoto; ALVES, Eduardo
This work studied a new protocol for organogenic calli induction and characterization of the morphology and ultrastructure of callogenesis in leaf explants of Passiflora gibertii N. E. Brown, a native passion fruit species from Brazil. Calli induction was performed in different growth conditions (light and dark), different MS medium salt concentrations (MS and MS half strength) and the presence or absence of coconut water. The leaf explants maintained in the dark were more responsive to bud formation. In order to reduce spending on in vitro culture, the most suitable induction medium for P. gibertii organogenesis could, therefore be the MS half strength salt concentration medium maintained in the dark. The addition of coconut water to the culture medium was essential for both calli induction and bud formation. The morphological and ultrastructural features of the organogenic calli were isodiametric cells, characterized by an organized cellular system, nucleus with prominent nucleoli, presence of starch grains and dense cytoplasm rich in endoplasmic reticulum. The scanning electron microscopy demonstrated that buds were present on these calli.