Navegando por Autor "PAIVA, Renato"

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Acesso aberto (Open Access)
Decontaminant solution on in vitro growth of Byrsonima intermedia seedlings
(2015-04) SILVA, Luciano Coutinho; PAIVA, Renato; VARGAS, Daiane Peixoto; SILVA, Diogo Pedrosa Corrêa da; BARBOSA, Sandro; HERRERA, Raírys Cravo
Byrsonima intermedia A. Juss., is a medicinal and fruit plant of the Cerrado in which the conventional propagation is difficult due to the presence of extremely lignified endocarps. Although sodium hypochlorite (NaOCl) is widely used in the surface decontamination, there are few reports of its effects on explant growth. The aim of this work was to study the effect of different pH and exposure periods of B. intermedia seeds to a NaOCl solution. Seeds were subjected to different exposure periods (1, 5 and 10 minutes) to a NaOCl solution at different pH (5, 7, 10 and 12) and after treatment with NaOCl, embryos were inoculated in a WPM medium with 50% concentration of salts without sucrose, 0.5% agar and pH 5.8 and after 75 days of culture the growth of seedlings was evaluated. The use of NaOCl is effective in the decontamination of B. intermedia seeds, independent of pH variation and exposure periods and the parameters such as percentage of normal seedlings, shoot length, and number of leaves are positively affected by the use of NaOCl solution at pH 8.5-8.9 and by increasing the exposure period, however, the number of roots is affected only by increasing the exposure period in the NaOCl solution.
Acesso aberto (Open Access)
Efeito da escarificação e luminosidade na germinação in vitro de sementes de cagaiteira (Eugenia dysenterica DC.)
(2007-12) MARTINOTTO, Cristiano; PAIVA, Renato; SANTOS, Breno Régis; SOARES, Fernanda Pereira; HERRERA, Raírys Cravo; SILVA, Álvaro Augusto Naves
Cagaiteira is a native specie of brazilian cerrado with high yield. Because it seeds show high variability, it is yet considered recalcitrant and dormant, the germination in vitro appears as an alternative for specie propagation, in addition to obtain juvenile explant for micropropagation. The present research aimed to evaluate the effect of scarification and ligth on germination in vitro of cagaiteira seeds. Seeds without teguments and intact seeds were inoculated in MS medium and kept in abscence and presence of radiation. Seeds without tegument germinated in the presence or abscence of ligth showed 86.25% and 88.25% germination at 31 and 71 days of inoculation, respectively. After 150 days of inoculation, plantlets from seeds without tegument germinated in the presence and abscence of ligth, showed 10% and 12% of abnormalities, respectively.
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)
Indução, análises morfológicas e ultraestruturais de calos de maracujazeiro nativo
(Universidade Federal do Pará, 2015-08) CARVALHO, Milene Alves de Figueiredo; PAIVA, Renato; HERRERA, Raírys Cravo; ALVES, Eduardo; CASTRO, Evaristo Mauro de; PAIVA, Patrícia Duarte de Oliveira; VARGAS, Daiane Peixoto
Analysis of calluses with embryogenic characteristics is important for subsequent in vitro regeneration of species with desirable agronomic traits such as the Passiflora gibertii native passion fruit. In this context, the present study aimed to analyze the induction of calluses from leaf explants of Passiflora gibertii N. E. Brown, as well as their morphologic and ultra-structural characterization. Cotyledonary leaves were inoculated in culture medium containing 2,4-D and picloram in association with kinetin. After 30 days of cultivation in the dark, the obtained calluses were prepared for the visualization in electron microscope (transmission and scanning) and light microscope. The results allowed to infer that the addition of picloram and kinetin to the culture medium promotes higher callus formation in cotyledonary leaf explants of P. gibertii than 2,4-D and kinetin. The growth regulator 2,4-D provides the formation of calluses with small isodiametric cells and small intercellular spaces, an organized cellular system and the predominance of round shaped mitochondria. Predominance of large and elongated cells with intercellular spaces, a non-organized cellular system and predominance of elongated mitochondria was observed when picloram was used.
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.
Acesso aberto (Open Access)
Métodos para a superação da dormência fisiológica de Caryocar brasiliense Camb.
(2010-06) DOMBROSKI, Jeferson Luiz Dallabona; PAIVA, Renato; ALVES, João Mauricio Cavalcante; SANTOS, Breno Régis; NOGUEIRA, Rairys Cravo; PAIVA, Patrícia Duarte de Oliveira; BARBOSA, Sandro
Caryocar brasiliense is a native species from Brazilian cerrado that has a considerable economic potential. The aim of this work was verifying the effect of substances with potential for seed germination stimulation. Seeds were extracted from the endocarps and set to germinate in paper rolls moistened with the following solutions: distilled water (Control); 2mmol L-1 KNO3 (Nitrate); 2mmol L-1 Etephon (ET); 1mmol L-1 GA3 (GA), 1mmol L-1 GA3 + 2mmol L-1 Etephon (GA + ET). The germination and the germination mean time were, respectively, 54.0% and 9.3 days in the GA treatment, 47.3% and 11.0 days in the GA + ET treatment, 32.0% and 12.2 days in the Control treatment, 30.7% and 13.1 days in the Etephon treatment, and 20.1% and 13.1 days in the Nitrate treatment. Low germination rates were observed in the GA + ET treatment up to the ninth day from sowing, when compared to the GA treatment, what indicates a possible seed germination inhibition due to ethylene presence.
Acesso aberto (Open Access)
Micropropagation of Maclura tinctoria L.: an endangered woody species
(2010-02) GOMES, Guilherme Augusto Canella; PAIVA, Renato; HERRERA, Raírys Cravo; PAIVA, Patrícia Duarte de Oliveira
Some native species produce seeds with low germination percentage and in most cases with dormancy, which makes the appearance of new individuals by sexual propagation difficult. The Maclura tinctoria has been considered an endangered species due to the indiscriminate use of its wood and low rate of seed germination. In this context, the objective of the present study was to establish an in vitropropagation methodology for this species. Combinations of NAA + BAP, different concentrations of GA3 and combinations IBA + activated charcoal were evaluated for shoot induction, shoot growth and root formation, respectively. The results indicated that the maximum shoot formation was obtained when 5.37 µM NAA + 4.45 µM BAP was used. The use of >5.48 µM GA3 promoted shoot growth. Root formation was observed on explants inoculated in WPM with a pH adjusted to 7.0 and supplemented with 23.62 µM IBA + 4.7 g L-1 activated charcoal. The use of a 70% light screen for 7 days followed by the use of 50 and 30% light screens also for 7 days each provided 97% plantlet survival.
Acesso aberto (Open Access)
Morfogênese in vitro de nim a partir de explantes cotiledonares
(2009) RODRIGUES, Marcelo; PAIVA, Renato; HERRERA, Raírys Cravo; MARTINOTTO, Cristiano; SILVA JÚNIOR, Jessé Marques
Azadirachta indica A. Juss, popularly known as neem, is a woody species widely used because of its insecticide, fungicide, bactericide, and nematicide properties. Seeds of neem were inoculated in WPM (Wood Plant Medium) containing different concentrations of gibberelic acid (GA3) (0, 3, 6, 9, and 12 mg L-1). After 30 days, cotyledons were inoculated in WPM supplemented with 0.0; 1.0; 2.0 and 3.0 mg L-1 acid 2,4-phenoxyacetic acid (2,4-D) and/or 0.0; 1.0; 2.0 and 3.0 mg L-1 6-benzylaminopurine (BAP). The cultures were kept in the dark at 28 ºC. Differentiated calli were evaluated based on their coloration and texture, and three subcultures were carried out on a monthly basis in WPM medium with 2.0 mg L-1 BAP, in the presence of light. Every 30 days, the number of differentiated shoot-buds was evaluated. WPM medium lacking GA3 promoted the highest in vitro seed germination indexes. Cotyledonary-derived explants cultured in WPM medium with 2.0 mg L-1 BAP yielded calli with high morphogenic potential. When those calli were transferred to medium with similar composition, a high shoot formation was achieved up to the third subculture.