Elias Terra Werner

Controle da calogênese do pau-brasil in vitro

The present work dealt with the in vitro control of callogenesis of brazilwood. The induction of callogenesis is the first step to obtain embryos and seeds. In order to control the callogenesis of Caesalpinia echinata, leaf discs of brazilwood in different developmental stages were used combined with the growth regulators 2,4-D (0, 5, 10, 20, 50, 100 mg/L) and 6-BAP (2,0 mg/L), cultivated in the Murashige and Skoog (1962) medium supplemented with sucrose (30 g/L), myo-inositol (100 mg/L) and agar (7,5 g/L). The effect of 6-BAP (0, 0,5, 1,0, 2,0, 5,0 and 10 mg/L) on the growth of meristematic shoot apexes was also tested. Juvenile leaves cultured with low concentrations of 2,4-D (5 and 20 mg/L) and young leaves treated with high concentrations of 2,4-D (50 and 100 mg/L) produced callus, without presenting significant differences between light and dark. As for the oxidation control, the best results were provided by activated charcoal, which inhibited callogenesis. The transfer of callus from the MS culture medium with high concentrations of 2,4-D (5,0, 10,0 and 20,0 mg/L) to the medium without growth regulators stimulated the formation of pro-embryonic masses (PEMs). The media without growth regulators, 2,0 mg/L of 2,4-D and 0,5 mg/L of 2,4-D, increased the number of embryogenic calluses and pre-embryonic masses. There were structures similar to global and heart shaped somatic embryos only at 0,5 mg/L 2,4-D .

Efeito do cloreto de cálcio na pós-colheita de goiaba Cortibel

The objective of this work was to extend the conservation period and maintain the quality of guavas (Psidium guajava L.) Cortibel, through the application of different concentrations of calcium chloride. The fruits were divided into four lots, the control (without calcium) and treatments, which received the application of CaCl2 to 1%, 2% and 3% (p/v) by immersion for 15 minutes. The parameters evaluated were fresh weight loss, pH, determination of firmness, total soluble solids content, total titratable acidity, ratio total soluble solids and total titratable acidity, amount of chlorophyll a and b and carotenoid, ascorbic acid content in the rind and pulp and activity of pectinmethylesterase. The 1% of CaCl2 concentration resulted in less fresh weight loss, keeping the firmness and reduced pectinmethylesterase activity, showing that calcium is important for fruit conservation, since it act in regulating the ripening. This concentration delays the loss of coloration and maintains the higher ascorbic acid content in the rind. However, there were no statistical differences from other CaCl2 concentrations regarding total soluble solids and pH. Moreover, it was verified that higher calcium concentrations do not further improve the post-harvest characteristics in guava.

Accelerated aging test to evaluate the quality of crambe (Crambe abyssinica Hochst - Brassicaceae) seed physiology

Este estudio tuvo como objetivo evaluar la eficacia de la prueba de envejecimiento acelerado, para determinar los efectos fisiologicos de semillas Crambe abyssinica Hochst, un monton de dos cosechas (2009 y 2010). Se evaluaron: contenido de agua, la germinacion y el vigor por el indice de velocidad de la germinacion, envejecimiento acelerado a 41, 43 y 45 °C durante periodos de 24, 48, 72 y 96 horas, el peso fresco y el peso seco. El experimento se llevo a cabo en el esquema factorial 2x3x5 (mucha x temperatura x tiempo de exposicion), en un diseno completamente al azar, con cuatro repeticiones de 25 semillas. El peso fresco y peso seco no son eficientes para diferenciar la calidad fisiologica de las semillas de Crambe abyssinica. Las influencias de envejecimiento acelerado, de manera similar, el porcentaje de germinacion y el vigor, con una mayor sensibilidad cuando las semillas son tratadas con temperaturas de 41 o 43 °C durante 72 h, lo que indica un papel prometedor para la estratificacion de la calidad fisiologica de la semilla crambe de lotes con germinacion similar.

Meios de cultura, reguladores de crescimento e fontes de nitrogênio na regulação da calogênese do pau-brasil (Caesalpinia echinata Lam.)

A regulacao da calogenese e o primeiro passo para a embriogenese somatica indireta in vitro. Nesse sentido, foram investigados os efeitos de diferentes meios de cultura, reguladores de crescimento e fontes nitrogenadas no desenvolvimento de calos em tecidos foliares de Caesalpinia echinata (pau-brasil). Explantes foliares foram cultivados em meios de cultura MS, B5, White e WPM. Testou-se, tambem, o efeito dos compostos nitrogenados (NH4NO3, KNO3 e glutamina) e a interacao entre auxinas (2,4-D, AIA e AIB) e citocininas (BAP e KIN) na desdiferenciacao celular indicado pela formacao de calos. Os meios MS, B5 e White nao foram significantemente diferentes e proporcionaram melhores resultados. Em meio MS contendo as fontes nitrogenadas 2,4 g L-1 NH4NO3 e 1,35 g L-1 glutamina + 4,11 g L-1 de KNO3 na presenca de 1,0 mg L-1 2,4-D e 5,0 mg L-1 BAP ocorreu maior proliferacao celular indicada pela massa fresca dos calos. As combinacoes dos reguladores 0,5 mg L-1 2,4-D + 5 mg L-1 BAP e 0,5 mg L-1 AIB + 5,0 mg L-1 BAP suplementado com 2,4 g L-1 NH4NO3 em meio MS estimularam o crescimento dos calos. De maneira geral, os calos apresentaram aspectos friaveis, nao embriogenicos, com acumulo de fenois e presenca de areas meristematicas (meristemoides).

GERMINAÇÃO IN VITRO DE Crambe abyssinica HOCHST

A germinacao in vitro para Crambe abyssinica Hochst e importante tanto para a propagacao massal, quanto como ferramenta para aplicacao de outras tecnicas biotecnologicas. O objetivo deste trabalho foi avaliar os efeitos de diferentes meios de cultura, condicoes fisicas da semente e condicoes de luminosidade na germinacao in vitro de crambe. O experimento foi conduzido em esquema de parcelas sub-subdivididas, tendo nas parcelas as condicoes luminosas (presenca ou ausencia de luz), nas subparcelas os meios de cultura (MS, WPM e B5) e nas sub-subparcelas as condicoes fisicas da semente (presenca ou ausencia de pericarpo). A porcentagem de germinacao foi maior nos meios B5 e WPM, com medias de 99,37% e 97,50%, respectivamente, independente da luz e das condicoes fisicas da semente. Os maiores valores de IVG foram observados tambem nesses meios com media de 3,87 na ausencia de luz em sementes sem pericarpo. O comprimento da parte aerea foi influenciado pela composicao do meio de cultura e condicao luminosa, em que, os meios B5 e WPM apresentaram os maiores valores na ausencia de luz, 13,2 e 11,7 cm, respectivamente. Os comprimentos das raizes foram significativamente maiores nos meios MS e B5, com medias de 6,8 e 5,0 cm, respectivamente, em relacao ao meio WPM, cuja media foi de 3,5 cm. Para as variaveis avaliadas, as condicoes mais favoraveis a germinacao e desenvolvimento das plantas in vitro sao em meio B5 ou WPM, na presenca ou ausencia de pericarpo e na presenca de luz.

Leaf anatomy of Crambe abyssinica Hochst. during in vitro shoot induction

This study aimed to characterize and evaluate possible modifications in the leaf anatomy of crambe during the process of shoot induction based on micropropagation protocol. The anatomic characteristics of the leaves, and also the morphological characteristics of crambe plantlets, were evaluated during the shoot induction phase of the micropropagation. The shoots were induced by the cytokinins, 6-benzylaminopurine (BAP), kinetin (KIN) and thidiazuron (TDZ), at distinct concentrations on Murashige and Skoog (MS) medium during 120 days of culture. Comparing the leaf anatomy, it was observed that, at day 30, only the adaxial epidermis and the palisade parenchyma presented significant differences in relation to the tested concentrations, independently of the type of cytokinin employed. At 120 days, the anatomic analysis of the mesophyll demonstrated no marked difference among the cytokinins at 5 μM. Therefore, the various sources and concentrations of cytokinins applied in this work did not promote marked changes in the sense of altering the organization and/or thickness compared to the control. Key words: Oilseeds, micropropagation, mesophyll, histology, plant morphology.