Change in leaf anatomy, physiology, and essential oil of Varronia curassavicaJacq. accessions under two light conditions / Cambio en la anatomía de la hoja, fisiología y aceite esencial de accesiones de Varronia curassavica Jacq. bajo dos condiciones de luz

The aim of this study was to evaluate the effect of light on anatomy, physiology and essential oil content and composition of Varronia curassavica. They were analysed two light conditions (full sunlight and protected environment with 50% shade screen) and five accessions (VCUR-101, VCUR-102, VCUR-201, VCUR-302, VCUR-802). V. curassavica cultivated in full sun presented a greater development of the leaf blade and palisade parenchyma thickness for all accessions. Chlorophyll levels did not differ according to the two light environments. The leaf area was larger in the protected environment. The essential oil yield of the accessions ranged from 0.26 to 0.87 mL/plant in full sun and from 0.34 to 0.53 mL/plant in the protected environment. The composition of the essential oil was influenced by the light and the accession. All accessions presented (E)-caryophyllene and α-humulene. The influence of light on the evaluated variables is genotype dependent.

El objetivo de este estudio fue evaluar el efecto de la luz sobre la anatomía, fisiología, el contenido y composición de aceites esenciales de Varronia curassavica. Se analizaron dos condiciones de luz (pleno sol y ambiente protegido con 50% de pantalla de sombra) y cinco accesiones (VCUR-101, VCUR-102, VCUR-201, VCUR-302, VCUR-802). V. curassavica cultivada a pleno sol presentó mayor desarrollo del limbo foliar y espesor del parénquima en empalizada para todas las accesiones. Los niveles de clorofila no difirieron según los dos entornos de luz. El área foliar fue mayor en el ambiente protegido. El rendimiento de aceite esencial de las accesiones varió de 0,26 a 0,87 mL/planta a pleno sol y de 0,34 a0,53 mL/planta en el ambiente protegido. La composición del aceite esencial fue influenciada por la luz y la accesión. Todas las accesiones presentaron (E)-cariofileno y α-humuleno. La influencia de la luz sobre las variables evaluadas depende del genotipo.

Ecophysiology and water use efficiency of soybean cultivars under field conditions

A wide range of soybean cultivars is available on the market and understanding the physiological response and yield of these materials is fundamental to develop new management systems. Thus, the objective of the present study was to assess ecophysiological parameters and yield of soybean cultivars under field conditions. The experiment was carried out on a farm located in the municipality of Açailândia, Maranhão, Brazil. Three commercial cultivars were used (SC1, SC2 and SC3), and gas exchanges, SPAD index, Fv/Fm, photosynthesis index (PI), instantaneous water use efficiency (WUE) and intrinsic instantaneous of the use of water (iWUE) were assessed during the vegetative (V5) and reproductive (R5) stages. In addition, the biomass and production components were obtained. A randomized complete block design was used, with three cultivars and six replications. SC2 obtained the best mean for the photochemical variables. SC2 was more efficient at both development stages in WUE, but the maximum iWUE values were obtained in SC3. The SC2 cultivar obtained the best responses in the main variables analyzed, resulting in a higher yield.

Producción de astaxantina bajo factores de estrés utilizando un biorreactor a escala de laboratorio de 5 L / Astaxanthin production under stress factors using a 5L laboratory scale bioreactor / Astaxanthin production under stress factors using a 5L laboratory scale bioreactor

Resumen Introducción. Haematococcus pluvialis es una microalga que produce astaxantina, un beta-caroteno y antioxidante muy usado en la industria. Para obtener una mayor producción de astaxantina se planteó como objetivo utilizar diferentes factores de estrés, en un biorreactor a escala de laboratorio de 5 litros. Metodología. Se cultivó la microalga en el medio RM, pH 6,8, temperatura 20±2°C, aire filtrado, iluminación con lámparas blancas 20h luz/4h oscuridad, irradianza 70 μE m-2s-1, diferentes concentraciones de acetato de sodio y cloruro de sodio. Se determinó crecimiento celular, cambios morfológicos y cuantificación de astaxantina y clorofila por espectrofotometría. Se realizó un análisis estadístico utilizando ANOVA (95%). Resultados. Utilizando 0,299 mg/L de acetato de sodio se obtuvo un crecimiento celular de 2,0 x 104 Cel/mL y una concentración de astaxantina de 2,530 μg/mL, mientras que con 1,6 mg/L de acetato de sodio el crecimiento celular fue de 3,5 x 104 Cel/mL y una concentración de astaxantina de 1,9 μg/ml. El tratamiento al cual se le adicionó 1,6 g/L de acetato de sodio y 6,4 g/L de cloruro de sodio presentó la mayor producción astaxantina 7,3 μg/ml. El tratamiento con acetato de sodio 0,320 g/L + cloruro de sodio 1,28 g/L presentó el mayor crecimiento celular con 1,64x105 células/ml. Conclusión. Esta investigación destaca la importancia de cultivar inicialmente la microalga utilizando el biorreactor Tecferm de 5 litros y después de su fase exponencial someterla a factores de estrés con acetato de sodio y cloruro de sodio lográndose así la mayor producción de astaxantina 7,325 μg/ml.

Abstract Introduction. Haematococcuspluvialis is a microalgae that produces astaxanthin, a beta-carotene and antioxidant widely used in industry. In order to obtain a higher production of astaxanthin, the objective was to use different stress factors, in a 5-liter laboratory-scale bioreactor. Methodology. The microalgae was cultivated in the RM medium, pH 6.8, temperature 20 ± 2°C, filtered air, illumination with white lamps 20h light/4h darkness, irradiance 70 μE m-2s-1, different concentrations of sodium acetate and chloride of sodium. Cell growth, morphological changes and quantification of astaxanthin and chlorophyll were determined by spectrophotometry. Statistical analysis was performed using ANOVA (95%). Results. Using 0.299 mg/L of sodium acetate a cell growth of 2.0 x 104 Cel/mL and an astaxanthin concentration of 2.530 μg/mL were obtained, while with 1.6 mg/L of sodium acetate the cell growth It was 3.5 x 104 Cel/mL and an astaxanthin concentration of 1.9 μg/mL. The treatment to which 1.6 g L of sodium acetate and 6.4 g/L of sodium chloride were added showed the highest astaxanthin production, 7.3 μg/ml. Treatment with 0.320 g/L sodium acetate + 1.28 g/L sodium chloride showed the highest cell growth with 1.64x105 cells/ml. Conclusion. This research highlights the importance of initially cultivating the microalgae using the 5-liter Tecferm bioreactor and, after its exponential phase, subjecting it to stress factors with sodium acetate and sodium chloride, thus achieving the highest production of 7.325 μg/ml astaxanthin.

Hydrographic variability in the Gulf of Papagayo, Costa Rica during 2017-2019 / Variabilidad hidrográfica en el Golfo de Papagayo durante el periodo 2017-2019

Introduction: The Gulf of Papagayo (GP) is a site of socioeconomic importance located in the North Pacific of Costa Rica. The ecosystem services of this site represent a benefit in local communities, and its dynamics are influenced by a coastal upwelling system that affects fishing and commercial activity. Objective: The objective of this study was to characterize the spatio-temporal variability of the main hydrographic parameters through measurements in situ during the period 2017-2019. Methods: Eight measurement campaigns were carried out, where a CTD probe was deployed to perform vertical profiles in 23 stations distributed throughout the GP, to characterize the variations in temperature, salinity, dissolved oxygen and chlorophyll concentration. Results: A minimum in surface and bottom temperature associated with upwelling caused by the wind was found in the first period of the year. The increase in salinity was associated with the decrease in temperature, being its highest value in the first period of the year, decreasing until reaching a minimum in November. The maximum chlorophyll concentration ​​coincided with the lowest surface temperatures and the minimum oxygen values were associated ​​with the minimum bottom temperatures, both occurring during the upwelling season. The parameter distribution was similar on dry and rainy seasons in stations located inside Bahía Culebra, likely attributed to the bathymetry effect. Conclusions: Bathymetry determines a south-north asymmetry for salinity and temperature. Subsurface cooling events coincide with strong wind periods. Upwelling influences the surface and bottom hydrographic dynamic in GP and determines the seasonal variability. The negative ENSO phase of 2018 corresponded with the strongest upwelling period, possibly promoting the interaction of upwelled coastal waters and the Costa Rica Thermal Dome.

Introducción: El Golfo de Papagayo (GP) es un sitio de alta importancia socioeconómica ubicado en el Pacifico Norte de Costa Rica. Los servicios ecosistémicos de este sitio representan un beneficio a las comunidades locales, y su dinámica está influenciada por un sistema de surgencia costera que influye en la actividad pesquera y comercial. Objetivo: El objetivo de este estudio fue caracterizar la variabilidad espacio-temporal de los principales parámetros hidrográficos a través de mediciones in situ durante el período 2017-2019. Metodología: Se realizaron 8 campañas de medición, donde se desplegó una sonda CTD para realizar perfiles verticales en 23 estaciones distribuidas en todo el GP, para caracterizar las variaciones de temperatura, salinidad, oxígeno disuelto y concentración de clorofila. Resultados: En el primer período del año se encontró una temperatura mínima de superficie y fondo asociada a la surgencia causada por el viento. El aumento de salinidad estuvo asociado a la disminución en la temperatura, siendo su valor más alto en el primer período del año y disminuyendo hasta alcanzar un mínimo en Noviembre. Los valores más altos de clorofila estuvieron relacionados con las temperaturas más bajas en superficie y los valores más bajos de oxígeno con las temperaturas más bajas en fondo. Se caracterizó la hidrografía de Bahía Culebra en relación con la parte externa de GP. Conclusiones: La batimetría determina una asimetría sur-norte de salinidad y temperatura. Los eventos de enfriamiento subsuperficiales coinciden con períodos de fuertes vientos. La surgencia influye en la dinámica hidrográfica de superficie y fondo en GP y determina la variabilidad interanual. El evento La Niña de 2018 mostró el período de surgencia más fuerte, posiblemente promoviendo la interacción de las aguas costeras y el Domo Térmico de Costa Rica.

Effect of climato-environmental parameters on chlorophyll a concentration in the lower Ganga basin, India / Efecto de los parámetros climáticos ambientales sobre la concentración de clorofila a en la cuenca baja del Ganges, India

Introduction: Chlorophyll a concentration proxies the phytoplankton biomass which directly involves in signifying the production functions of aquatic ecosystem. Thus, it is imperative to understand their spatio-temporal kinetics in lotic environment with reference to regional climatic variabilities in the tropical inland waters. Objective: In-situ studies were conducted to examine the changes in phytoplankton biomass in lower Ganga basin as influenced by various environmental parameters under regional climatic variability during 2014-2016. Methods: Firstly, the most key influential environmental parameters on riverine Chl-a concentration were determined. Then the direct cascading effect of changing climatic variables on key environmental parameters were derived through modeling and quantified probable changes in mean Chl-a concentration in the lower stretch of river. Results: Only five environmental parameters namely water temperature, total dissolved solid, salinity, total alkalinity and pH were key factors influencing Chl-a (Multiple R2: 0.638, P < 0.05). Present estimates indicate that if the present rate of regional climatic variability over the last 3 decades (mean air temperature + 0.24 °C, total annual rainfall -196.3 mm) remain consistent over the next three decades (2015-2045), an increase in mean Chl-a by + 170 µgL-1 may likely be expected grossly reaching about 475.94 µg L-1 by the year 2045 or more. Conclusions: The present study is first such comprehending a gross hint towards the probable ecosystem response with an alternative model based methodology in data-deficient situations. Subsequently, the output would also be of great benefit for increase water governance and developing strategy protocol for sustainable water management for greater ecosystem services.

Introducción: La concentración de clorofila a representa la biomasa de fitoplancton la cual influye directamente en las funciones de producción de los ecosistemas acuáticos. Por lo tanto, es imperativo comprender su cinética espacio-temporal en el ambiente lótico con respecto a las variabilidades climáticas regionales en las aguas continentales tropicales. Objetivo: Se realizaron estudios in situ para examinar la influencia de varios parámetros ambientales en la biomasa del fitoplancton en la cuenca baja del Ganges durante 2014-2016. Métodos: En primer lugar, se determinaron los parámetros ambientales más influyentes en la concentración de Chl-a fluvial. Luego, el efecto directo en cascada de las variables climáticas sobre los parámetros ambientales clave, mediante el modelado y los cambios en la concentración media de Chl-a en el tramo inferior del río. Resultados: Solo cinco parámetros ambientales, entre ellos, temperatura del agua, sólidos disueltos totales, salinidad, alcalinidad total y pH, fueron factores clave que influyeron en la Chl-a (R2 múltiple: 0.638, P < 0.05). Las estimaciones actuales indican que si la tasa actual de variabilidad climática regional durante las últimas 3 décadas (temperatura media del aire + 0.24 °C, precipitación total anual -196.3 mm) permanece constante durante las próximas tres décadas (2015-2045), se presente un aumento en el promedio de la Chl-a en +170 µgL-1 y alcance aproximadamente 475.94 µgL-1 para el 2045 o más. Conclusiones: Este estudio presenta una metodología basada en modelos alternativos en situaciones de escasez de datos, la información generada también podría contribuir a mejorar la gobernanza del agua y a desarrollar un protocolo para la gestión sostenible del agua y de esta manera mejorar los servicios ecosistémicos.

Physiological changes in Solanum lycopersicum L. in the presence of root-knot nematodes and salicylic acid / Alterações fisiológicas em Solanum lycopersicum L. na presença de nematóides das galhas e ácido salicílico

Nematodes of the genus Meloidogyne spp. are one of the tomato culture's main pathogens. According to their soil infestation level, physiological changes may occur. Consequently, it is extremely important to employ given products to minimize their effect. A feasible option is the salicylic acid, a phytohormone that can induce into resistance due to its ability to increase the production level of some pathogenicity proteins. Therefore, the purpose hereof was to assess the effect of salicylic acid on the physiology of tomato plants subject to different populational densities of Meloidogyne javanica. The design employed was one of randomized blocks, in an incomplete factorial scheme, using the Box Central Compound (BCC) matrix with five nematode populational densities (PD) (0; 5815; 20000; 34184; and 40000 eggs per plant) and five salicylic acid doses (0.0; 0.29; 1.0; 1.71; and 2.0 mM), with four repetitions and two plants per experimental patch. The gas exchanges, fluorescence, and chlorophyll levels were evaluated 45 days after the transplant and soil infestation. The data were submitted for analysis of variance through the F test and, in the significance cases, the polynomial regression analysis was performed. For stomatal conductance, a greater reduction was seen at the PD of 21755 eggs per plant, a fact that might have decreased the liquid assimilation of CO2 and the efficiency of carboxylation. The salicylic acid (SA) affected the CO2 liquid assimilation and the efficiency of carboxylation. The infestation of M. javanica in tomato plants negatively affected the gas exchange and the chlorophyll levels because the SA application did not mitigate the negative effect thereof.

Os nematoides do gênero Meloidogyne spp. são um dos principais patógenos na cultura do tomate, podendo causar alterações fisiológicas em função do nível de infestação do solo. O uso de produtos que minimize seus efeitos é de suma importância, nesse sentido, o ácido salicílico pode ser uma alternativa viável, visto que, esse fitormônio pode induzir a resistência devido à capacidade de proporcionar um aumento na produção de algumas proteínas de patogenicidade. Com isso, objetivou-se avaliar o efeito do ácido salicílico na fisiologia do tomateiro submetido a diferentes densidades populacionais de Meloidogyne javanica. O delineamento utilizado foi o de blocos casualizados, em esquema fatorial incompleto, utilizando-se a matriz Composto Central de Box (CCB) com cinco densidades populacionais (DP) de nematoides (0; 5815; 20000; 34184 e 40000 ovos por planta) e cinco doses de ácido salicílico (0,0; 0,29; 1,0; 1,71 e 2,0 mM), com quatro repetições e duas plantas por parcela experimental. Foram avaliadas as trocas gasosas, fluorescências e índices de clorofilas aos 45 dias após o transplantio e infestação do solo. Os dados foram submetidos à análise de variância pelo teste F e nos casos de significância foi realizada análise de regressão polinomial. Para a condutância estomática, observou-se uma maior redução na DP de 21755 ovos por planta, fato que pode ter ocasionado reduções na assimilação líquida de CO2 e na eficiência de carboxilação. O ácido salicílico (AS) influenciou na assimilação líquida de CO2 e eficiência de carboxilação. A infestação por M. javanica em plantas de tomateiro influenciou negativamente nas trocas gasosas e nos teores de clorofila, sendo que a aplicação do AS não atenuou os efeitos negativos desses patógenos.

Chlorophyll treatment combined with photostimulation increases glycolysis and decreases oxidative stress in the liver of type 1 diabetic rats

Photodynamic therapy (PDT) promotes cell death, and it has been successfully employed as a treatment resource for neuropathic complications of diabetes mellitus (T1DM) and hepatocellular carcinoma. The liver is the major organ involved in the regulation of energy homeostasis, and in pathological conditions such as T1DM, changes in liver metabolic pathways result in hyperglycemia, which is associated with multiple organic dysfunctions. In this context, it has been suggested that chlorophyll-a and its derivatives have anti-diabetic actions, such as reducing hyperglycemia, hyperinsulinemia, and hypertriglyceridemia, but these effects have not yet been proven. Thus, the biological action of PDT with chlorophyll-a on hepatic parameters related to energy metabolism and oxidative stress in T1DM Wistar rats was investigated. Evaluation of the acute effects of this pigment was performed by incubation of isolated hepatocytes with chlorophyll-a and the chronic effects were evaluated by oral treatment with chlorophyll-based extract, with post-analysis of the intact liver by in situ perfusion. In both experimental protocols, chlorophyll-a decreased hepatic glucose release and glycogenolysis rate and stimulated the glycolytic pathway in DM/PDT. In addition, there was a reduction in hepatic oxidative stress, noticeable by decreased lipoperoxidation, reactive oxygen species, and carbonylated proteins in livers of chlorophyll-treated T1DM rats. These are indicators of the potential capacity of chlorophyll-a in improving the status of the diabetic liver.

Efecto de la interacción luz-agua sobre la fotosíntesis de la Vanilla planifolia (Orchidaceae) / Light-water interaction effect on photosynthesis of the Vanilla planifolia (Orchidaceae)

Introducción: La vainilla (Vanilla planifolia Andrews) es una planta CAM de gran importancia económica en el mercado mundial de saborizantes y aromatizantes. Por ser una planta hemiepífita que inicialmente crece en el sotobosque sombreado y posteriormente asciende hasta el dosel, se aclimata a diferentes condiciones de radiación y humedad. La posibilidad de extender su cultivo a zonas secas donde sea menor la incidencia de enfermedades, dependerá de su respuesta a períodos prolongados de sequía. Objetivo: Evaluar los efectos de la interacción entre la radiación y la humedad sobre los parámetros de la fotosíntesis y funcionamiento del CAM de plantas de vainilla en sus fases iniciales de desarrollo vegetativo, y determinar si las condiciones de radiación en las que crece la planta pueden ayudar a moderar los efectos negativos de la sequía. Métodos: Se evaluaron plantas de vainilla que crecieron con riego durante 18 meses en casetas con iluminación relativa (IR) de 8, 17, 31 y 67 %; posteriormente se suspendió el riego y se fueron deshidratando durante 94 días hasta alcanzar un contenido de humedad crítico (contenido hídrico relativo, CHR ≤ 50 %), y finalmente se reinició el riego durante 22 días; se evaluó el efecto de estos procesos sobre la asimilación de CO2, la acidez titulable y la eficiencia cuántica del Fotosistema II (Fv/Fm). Resultados: Bajo condiciones intermedias de IR (17 % y 31 %), la asimilación de CO2 y laacumulación nocturna de ácidos orgánicos presentaron la menor afectación por el déficit hídrico, así como la mejor recuperación luego de la rehidratación. El CHR se vio más afectado por la disponibilidad de agua en el tejido vegetal, mientras que Fv/Fm lo fue por el ambiente de radiación. Los efectos combinados de estrés hídrico y alta radiación ocasionaron daños irreversibles en la fotosíntesis para el tratamiento de IR de 67 %. Conclusiones: En las plantas de vainilla, el impacto negativo de la sequía sobre los parámetros de la fotosíntesis fue mayor en alta radiación; sin embargo, en condiciones de baja radiación también aumentó la susceptibilidad de las plantas a la sequía, en comparación con los ambientes de radiación intermedia, en los cuales la densidad de flujo de fotones media fue de 340 μmol m-2 seg-1 (17 % de IR) y 620 μmol m-2 seg-1 (31 % de IR). Estos resultados sugieren el potencial de cultivar vainilla en zonas con sequía estacional bajo sistemas productivos de baja tecnificación, manteniendo estas condiciones de radiación.

Introduction: Vanilla planifolia Andrews is a CAM plant of economic importance in the global market of flavorings and essences. Being a hemiepiphyte which initially grows in the shady understory and later climbs to the canopy, it acclimates to different conditions of radiation and humidity. The possibility of extending this crop to dry areas where the incidence of diseases is lower will depend on the response to prolonged periods of drought. Objective: To evaluate the effects of the interaction of radiation and humidity on the parameters of photosynthesis and operation of CAM of vanilla plants, and to determine if the radiation environment could help to moderate the negative effects of drought. Methods: We evaluated well-watered vanilla plants grown for 18 months in relative illumination (RI) of 8, 17, 31 and 67 %, which underwent dehydration for 94 days until reaching critical water content (relative water content, RWC < 50 %) and then rehydration for 22 days; variables evaluated were: CO2 assimilation, titratable acidity, and quantum efficiency of Photosystem II (Fv / Fm). Results: Under intermediate conditions of radiation (17 % and 31 % RI), CO2 assimilation and nocturnal accumulation of organic acids were less affected by water deficit and also showed the best recovery after rehydration. The RWC was most affected by the water available in plant tissue, while Fv / Fm was affected by radiation. The combined effects of water stress and high radiation caused irreversible damage to photosynthesis for the 67 % RI treatment. Conclusions: In vanilla plants, the negative impact of drought on photosynthetic parameters was greater in high radiation; however, in low radiation conditions the susceptibility of plants to drought also increased, as compared to intermediate radiation environments, which were under a mean photon flux density of 340 µmol m-2 s-1 (17 % IR) and 620 µmol m-2 s-1 (31 % IR). These results suggest the potential for growing vanilla in areas with seasonal drought under low-tech production systems, maintaining these radiation conditions.

An efficient antioxidant system is associated with lower photosynthesis photoinhibition and greater toleranc e to drought in sugarcane cultivars / Um eficiente sistema antioxidante está associado a menor fotoinibição da fotossíntese e maior tolerância à seca em cultivares de cana-de-açúcar

The occurrence of seasonal droughts is one of the main factors that limit the sugarcane ratoon cycles, compromising sugarcane field longevity. The aim of this study was to evaluate the biochemical responses of sugarcane cultivars to drought stress in ratoon crop. Six cultivars were used: RB72910, RB99382, RB72454, RB92579, RB855536 and RB931011, and three water regimes based on soil available water content(SAWC) and defined as: control, 80 to 100% (SAWC); moderate water stress, 40 to 60% (SAWC), and severewater stress, 0 to 20% (SAWC). Cultivar RB72454 was most sensitive to water deficit. When under stress, this cultivar showed an increased production of hydrogen peroxide, but without concomitant increase in the activity of the antioxidant enzymes ascorbate peroxidase, catalase and superoxide dismutase. Oxidative stress led to lipid peroxidation and chlorophyll degradation, resulting in higher photochemical photoinhibition. On the other hand, cultivar RB92579 was the most tolerant to drought, with increased activity of antioxidant enzymes, which led to low lipid peroxidation, maintenance of photosynthetic pigments and photochemical activity. The antioxidant defense system triggered by ascorbate peroxidase, catalase and superoxide dismutase enzymes appears to be a key protection factor to photochemical complexes of chloroplast of sugarcane plants under water stress. The increase in the antioxidant system as well as the maintenance of photosynthetic pigments and cell membranes served as important criteria to indicate cultivars more tolerant to drought stress.

A ocorrência de secas sazonais é um dos principais fatores que limitam a longevidade do canavial. Esse trabalho teve como objetivo avaliar as respostas bioquímicas de cultivares de cana-de-açúcar em seu segundo ciclo de cultivo a condições de estresse hídrico. Para tanto, foram utilizadas seis cultivares: RB72910, RB99382, RB72454, RB92579, RB855536 e RB931011, e três regimes hídricos, baseado na capacidade de água disponível (CAD) e definidos como: controle, 80 a 100% (CAD); estresse hídrico moderado, 40 a 60% (CAD), e estresse hídrico severo, 0 a 20% (CAD). A cultivar RB72454 se mostrou a mais sensível ao déficit hídrico. Essa cultivar mostrou aumento na produção de peróxido de hidrogênio, mas sem aumento concomitante das enzimas antioxidantes ascorbato peroxidase, catalase e superóxido dismutase. Esse estresse oxidativo levou a peroxidação de lipídeos das membranas e degradação das clorofilas, resultando na diminuição da eficiência fotoquímica do PSII. Por outro lado, a cultivar RB92579 foi a mais tolerante à seca, com aumento de atividade das enzimas antioxidantes, que levou a baixa peroxidação de lipídeos, manutenção dos pigmentos fotossintéticos e da eficiência fotoquímica do PSII. O sistema de defesa antioxidante desencadeado pelas enzimas ascorbato peroxidase, catalase e superóxido dismutase parece ser o fator chave de proteção à fotoinibição de plantas de cana-de-açúcar sob estresse hídrico. O aumento do sistema antioxidante, bem como a manutenção dos pigmentos fotossintéticos e das membranas celulares serviram como critérios importantes para indicar cultivares mais tolerantes ao estresse hídrico.

Estabilidade térmica de pigmentos em óleo de abacate, arroz e azeite de oliva / Thermal stability of pigments in avocado, rice and olive oil

Sabe-se que o aquecimento do óleo pode alterar sua composição, degradando ácidos graxos e compostos minoritários. Assim, objetivou-se avaliar a estabilidade térmica dos pigmentos carotenoides e clorofilas no óleo de abacate produzido nacionalmente, em comparação com óleo de arroz e azeite de oliva após aquecimento a 180 ºC em micro-ondas, por 3, 6, 9 e 12 minutos. Observaram-se diferenças significativas entre as amostras em todos os tempos de análise, tanto para clorofilas quanto para carotenoides. Na avaliação ao longo do tempo de aquecimento somente foi verificada alteração significativa no teor de clorofilas do azeite de oliva, ainda que no óleo de abacate os percentuais de perda tenham sido maiores. Verificou-se que os teores dos pigmentos avaliados foram significativamente maiores no óleo de abacate em relação ao azeite de oliva e o óleo de arroz, mesmo após o aquecimento por 12 minutos. Destaca-se a importância destas informações para estimular o consumo do óleo de abacate.

Cadmium tolerance of Typha domingensis Pers. (Typhaceae) as related to growth and leaf morphophysiology / A tolerância ao cádmio por Typha domingensis Pers. (Typhaceae) correlacionada com o crescimento e a morfofisiologia foliar

Abstract Typha domingensis (cattail) is a native macrophyte known by its capacity to tolerate several heavy metals effects and the potential use for phytoremediation. However, in despite that cadmium (Cd) is one of the most toxic pollutants; its effects in T. domingensis biology remain uninvestigated. Thus, the objective of this study was to study the tolerance of T. domingensis to cadmium contamination by evaluating its growth, Cd uptake, leaf anatomy and gas exchange. The experiment was designed using three cadmium concentrations (0, 10 and 50 µM) and ten replicates for 90 days. The cadmium uptake, growth, gas exchange, chlorophyll content and leaf anatomy were evaluated. Data was submitted to ANOVA and Scott-Knott test for P<0.05. Typha domingensis accumulates Cd proportionally to its concentration on the solution and the content of this metal was higher in roots as compared to shoots. Plants showed no significant modifications on growth parameters such as the biomass production, number of leaves, number of clones and the biomass allocation to organs. The photosynthesis, transpiration and chlorophyll content were not modified by Cd. Most anatomical traits evaluated were not modified by the metal but the stomatal density and the proportion of vascular tissues were reduced under 50 µM of Cd. In despite, the leaf anatomy showed no toxicity evidences for any Cd level. The absence of growth reduction and the stability of anatomical and physiological traits give insight about the Cd tolerance of this species. Therefore, T. domingensis is able to overcome Cd toxicity and shows potential for phytoremediation.

Resumo A espécie Typha domingensis (taboa) é uma macrófita nativa conhecida por sua tolerância a vários metais pesados e potencial uso na fitorremediação. Contudo, apesar de que o Cd é um dos poluentes mais tóxicos; Seus efeitos em T. domingensis ainda não foram investigados. Assim, o objetivo desse estudo foi avaliar a tolerância de T. domingensis ao cádmio, avaliando o crescimento, absorção de Cd, anatomia foliar e trocas gasosas. O experimento foi conduzido utilizando três concentrações de Cd (0, 10 e 50 µM) e dez repetições por 90 dias.. O crescimento, trocas gasosas e o teor de clorofila e anatomia foliar foram avaliados. Os dados foram submetidos à ANOVA e ao teste de Scott-Knott para P<0,05. A absorção de cádmio, crescimento, trocas gasosas, teor de clorofila e anatomia foliar foram analisados. As plantas de T. domingensis podem acumular Cd proporcionalmente à sua concentração na solução e o teor deste metal foi maior nas raízes em comparação com a parte aérea. As plantas não apresentam modificações significativas nos parâmetros de crescimento como produção de biomassa, número de folhas, número de clones produzidos e alocação de biomassa nos órgãos. A fotossíntese, transpiração e conteúdo de clorofila não foram afetados de forma significativa pelo Cd. A maioria das características anatômicas avaliadas não apresentou diferenças, mas houve redução na densidade estomática e na proporção de tecidos vasculares na concentração de 50 µM de Cd. A anatomia foliar não mostrou evidências de toxicidade em nenhum dos níveis de Cd. A ausência de redução de crescimento e estabilidade das características anatômicas e fisiológicas caracteriza alta tolerância da espécie ao Cd. Portanto, T. domingensis é capaz de superar a toxicidade do Cd e demostra potencial para fitorremediação.

Aquaculture biological waste as culture medium to cultivation of Ankistrodesmus gracilis (Reinsch) Korshikov / Resíduos biológicos de aquicultura como meio de cultura para o cultivo de Ankistrodesmus gracilis (Reinsch) Korshikov

Abstract Current study investigated the effectiveness of different macrophytes as culture media for Ankistrodesmus gracilis in laboratory conditions. Significant difference (p < 0.05) was reported in cell density with regard to conventional culture medium (CHU12) and macrophytes culture media. Mean cell density in NPK, Eichhornia crassipes and E. azurea media was higher (p < 0.05) than in conventional culture medium. Chlorophyll-a was higher than 1 g.L-1, except in CHU12 (0.7 ± 0.4 g.L-1) and T. domingensis (0.8 ± 0.3 g.L-1) media. Nitrate decreased sharply as from the 7th-day of the experiment. Ammonium and total phosphorus were highest in culture media and ranged between 0.4 g.L-1 (P. cordata medium) and 1.7 g.L-1 (CHU12 medium) for ammonium, and between 0.8 g.L-1 (CHU12 medium) and 1.9 g.L-1 (T. domingensis medium) for total phosphorus. Results revealed inorganic fertilizer and macrophytes combined with vitamins may be effective as culture media and strongly supports the growth of Ankistrodesmus gracilis, since cell density and biochemical composition are similar to or higher than conventional culture medium (CHU12). Macrophyte is a tool for aquaculture since biological wastes may be used with nutrients to improve the cultivation of microalgae.

Resumo O presente estudo investigou a eficácia na utilização de diferentes macrófitas como meio de cultura para Ankistrodesmus gracilis em condições laboratoriais. Foi observada diferença significativa (p < 0,05) entre a densidade celular em relação aos meios de cultura convencional (CHU12) e de macrófitas. Os meios de cultura com Eichhornia crassipes, E. azurea e NPK apresentaram densidade celular maiores (p < 0,05) que o meio de cultura convencional. Os teores de clorofila-a foram superiores a 1 g.L-1, exceto nos meios de cultura CHU12 (0.7 ± 0.4 g.L-1) e de T. domingensis (0.7 ± 0.3 g.L-1). O nitrato diminuiu acentuadamente a partir do 7º dia de experimento. Dentre os nutrientes, amônia e o fósforo total foram os mais elevados nos meios de cultura, variando entre 0.4 g.L-1 (meio de P. cordata) a 1,7 g.L-1 (meio CHU12) para amônia e, entre 0.8 g.L-1 (meio CHU12) e 1,9 gL-1 (meio de T. domingensis) para o fósforo total. Os resultados do presente estudo mostraram que o uso de fertilizantes inorgânicos e macrófitas, combinados com vitaminas, pode ser eficaz como meio de cultura no crescimento de Ankistrodesmus gracilis, uma vez que a densidade celular e a composição bioquímica foram semelhantes ou superiores ao meio de cultura convencional (CHU12). As macrófitas são ferramentas a serem adotadas na aquicultura, desde que os resíduos biológicos podem ser usados como nutrientes para melhorar o cultivo de microalgas.

Biochemical, physiological and growth changes in response to in vitro salinity in sugarcane / Alterações bioquímicas, fisiológicas e de crescimento em resposta à salinidade in vitro em cana-de-açúcar

Abiotic stresses in plants have aroused great research interest, unceasingly seeking for more productive cultivars under unfavorable cultivation conditions. Water deficiency and soil salinity are the most studied aspects, due to their strong impact on the growth and productivity of plants. The objective of this study was to evaluate accessions of different sugarcane species (Saccharum spp., S. robustum, S. officinarum) regarding tolerance to in vitrosalinity, from changes in physiological, anatomical, biochemical and biometric parameters, to assist in breeding programs. To this end, shoots were used, grown on Murashige and Skoog medium, supplemented with 2% of sucrose and 4 g.L-1Phytagel, in the presence of five concentrations 0, 50, 100, 150, 200 mM NaCl. Shoots length, roots length, shoots number, roots number, fresh weight, dry weight, proline content in leaves, total chlorophyll content, and morphological changes to the leaf tissue were analyzed. The in vitro growth of accessions Saccharum robustum, Saccharum spp. and Saccharum officinarum are affected by salinity induced by NaCl. The proline accumulation and chlorophyll decrease are intensified in Saccharum spp., in addition to changes in cell's anatomy, characterized as more sensitive to salt.(AU)

Os estresses abióticos em plantas têm despertado grande interesse da pesquisa, que tem buscado incessantemente por cultivares mais produtivas sob condições desfavoráveis de cultivo. A deficiência hídrica e a salinidade do solo são os mais estudados, em razão de seu forte impacto sobre o crescimento e a produtividade das plantas. O objetivo deste estudo foi avaliar acessos de diferentes espécies de cana-de-açúcar (Saccharum robustum, Saccharum spp., S. officinarum), quanto a tolerância à salinidade in vitro, a partir de alterações nos parâmetros fisiológicos, anatômicos, bioquímicos e biométricos, para auxiliar em futuros programas de melhoramento. Para tanto foram utilizadas brotações, cultivadas em meio Murashige e Skoog, suplementado com 2% de sacarose e 4 g.L-1 de Phytagel, na presença de cinco concentrações 0, 50, 100, 150, 200 mM de NaCl. Comprimento das brotações e da raiz, número de brotações e de raízes, peso fresco, peso seco, teor de prolina nas folhas, conteúdo de clorofila total e alterações morfológicas dos tecidos foliares foram analisados. O crescimento in vitro dos acessos Saccharum robustum, Saccharum spp. e Saccharum officinarum é afetado pela salinidade induzida por NaCl. O acúmulo de prolina e decréscimo de clorofila é intensificado em Saccharumspp., além de mudança na anatomia de células, caracterizando-se como mais sensível ao sal.(AU)

Sbaja a novel foliar applied growth and yield enhancer in Malaysia / Sbaja, um novo potenciador de crescimento foliar aplicado e de rendimento na Malásia

Product efficacy testing during 2006 to 2010 with SBAJA (a novel scientifically formulated foliar-spray growth and yield enhancer) in the greenhouse and multi-location field trials registered measurable increase in chlorophyll contents, robust and healthier crop growth and increased yield and biomass production. In field trial, rice plants receiving normal NPK fertilizer at the rates of 100:50:30 served as control and spray treated with SBAJA at 40 and 60 days after sowing (DAS). All the experiments were laid out in Randomized Complete Block (RCB) Design and replicated five times. Tiller number and panicle characteristics; length, weight, number of grains, number of filled grains were significantly increased with 1:300 SBAJA treatment. In addition, 1000 grain weight and rice yield increased significantly with SBAJA treatments. Normal fertilizer applications in field trials augmented with SBAJA in 2008-2010 in the Selangor North West Project (SNWP), registered measurable increase in rice yields by 25-30% from 6.2 - 6.5 tons/ha to 7.8 - 8.9 tons/ha. It is concluded that foliar spraying with SBAJA at 40 and 60 days after sowing increased growth and yield of rice under green house and field conditions.

Os testes de eficácia do produto durante 2006 a 2010 com SBAJA (um novo spray foliar cientificamente formulado) em estufa e ensaios de campo em várias localizações registraram aumento mensurável nos teores de clorofila, crescimento robusto e mais saudável das culturas e aumento do rendimento e da produção de biomassa. No ensaio de campo, plantas de arroz recebendo adubo NPK normal nas doses de 100:50:30 serviram como controle e foram tratadas com SBAJA aos 40 e 60 dias após a semeadura (DAS). Todos os experimentos foram dispostos no formato Randomized Complete Block (RCB) e replicados cinco vezes. Número de perfilhos e características da panícula; comprimento, peso, número de grãos, número de grãos preenchidos foram significativamente aumentados com o tratamento com 1:300 SBAJA. Além disso, o peso de 1000 grãos e o rendimento de arroz aumentaram significativamente com os tratamentos da SBAJA. Aplicações normais de fertilizantes em testes de campo aumentados com a SBAJA em 2008-2010 no Projeto Selangor North West (SNWP), registraram aumento mensurável na produção de arroz de 25-30% de 6,2 a 6,5 toneladas/ha para 7,8 a 8,9 toneladas/ha. Conclui-se que a pulverização foliar com SBAJA aos 40 e 60 dias após a semeadura aumentou o crescimento e o rendimento do arroz em estufa e em campo.

Growth and physiology of citrus rootstocks under salt stress / Crescimento e fisiologia de porta-enxertos de citros sob estresse salino

In order to study the growth and physiology of citrus rootstocks under saline water irrigation, during formation of rootstocks, an assay was carried out in a factorial scheme, 2 x 6, corresponding to two levels of salinity of the nutrient solution: 0.3 and 4.0 dS m-1 and six genotypes provided by the Citrus Breeding Program of Embrapa Cassava & Fruits-CBP, distributed in randomized block design with three replications. The genotypes were: 1.'Santa Cruz Rangpur' lime (SCRL) (Citrus limonia Osbeck), 2. 'Florida Rough' lemon (FRL) (Citrus jambhiri Lush.), 3. 'Volkamer' lemon (VKL) (C. volkameriana V. Ten. &Pasq.), 4. CSM x SWC- 028, 5. CSM x SWC- 033 and 6.CSM x SWC-041, the last three hybrids of common 'Sunki' mandarin (CSM) [C.sunki (Hayata) hort. ex Tanaka] with 'Swingle' citrumelo (SWC) [C. paradisi Macfad. x Poncirus trifoliata (L.) Raf.]. Nucellar plants from these genotypes were grown in alternative hydroponic system, using Leonard jars. Application of nutrient solution made with saline water started from 90 days after sowing until 120 days, when the growth and physiology parameters of plants were evaluated. Salt stress influenced the growth and physiological parameters in all genotypes. Salt stress did not influence the chlorophyll a fluorescence in the genotypes VKL and CSM x SWC- 041, indicating no damage to the photosynthetic apparatus. The CSM x SWC- 041, 'Santa Cruz Rangpur' lime, 'Florida Rough' lemon and 'Volkamer' lemon are the more tolerant genotypes to salinity based on growth rate.

A fim de estudar o crescimento e a fisiologia de porta-enxertos de citros sob irrigação com água salina, durante a formação de porta-enxertos, realizou-se um ensaio fatorial 2 x 6, correspondente a dois níveis de salinidade da solução nutritiva: 0,3 e 4,0 dS m-1 e seis genótipos fornecidos pelo Programa de Melhoramento de Citros da Embrapa Mandioca & Fruticultura-PMGC, distribuídos em delineamento em blocos casualizados com três repetições. Os genótipos foram: 1. 'limoeiro Cravo Santa Cruz' (LCRSTC) (Citrus limonia Osbeck), 2. 'limoeiro Rugoso da Flórida' (LRF) (Citrus jambhiri Lush.), 3. 'limoeiro Volkameriano' (LVK) (C. Volkameriana V. Ten. & Pasq.), 4. CSM x SWC- 028, 5. CSM x SWC- 033 e 6. CSM x SWC-041, os últimos três híbridos de tangerineira 'Sunki' comum (CSM) [C. sunki (Hayata) hort. Ex Tanaka] com citrumelo 'Swingle' (SWC) [C. Paradisi Macfad. x Poncirus trifoliata (L.) Raf.] Plantas de origem nucelar desses genótipos foram cultivadas em sistema hidropônico alternativo, utilizando vasos Leonard. A aplicação de solução nutritiva feita com água salina iniciou-se a partir de 90 dias após a semeadura até 120 dias, quando foram avaliados os parâmetros de crescimento e fisiologia das plantas. O estresse salino influenciou o crescimento e os parâmetros fisiológicos em todos os genótipos. O estresse salino não influenciou a fluorescência da clorofila a nos genótipos VKL e CSM x SWC-041, indicando não haver danos ao aparelho fotossintético. O CSM x SWC-041, 'limoeiro Cravo Santa Cruz', 'limoeiro Rugoso da Flórida' e 'limoeiro Volkameriano' são os genótipos mais tolerantes à salinidade com base na taxa de crescimento.

Influence of tannery wastewater sludge doses on biometric and chlorophyll fluorescence parameters in conilon coffee / Influence of tannery wastewater sludge doses on biometric and chlorophyll fluorescence parameters in conilon coffee = Influência de doses de lodo de curtume nos parâmetros biométricos e de fluorescência da clorofila em café conilon

Tannery wastewater sludge is an industrial residue that can be used in the pure form or associated to other residues, such as byproduct production from cultivated plants. The objective of the present study was to assess substrate composition for producing conilon coffee stem cuttings, varying increasing tannery wastewater sludge doses. A randomized block design was used with four treatments, three increasing doses of tannery wastewater sludge and one conventional treatment. The stem cuttings were assessed for parameters related to photosystem II functioning and biometry. The results indicated that substrates consisting of tannery wastewater sludge, humus and subsoil promote, in general, improvement in plant growth compared to conventional substrates, highlighting the Dickson quality index. Both chlorophyll fluorescence parameters and chlorophyll contents estimates were not affected by using tannery wastewater sludge in the mixture to formulate substrate for conilon coffee stem cuttings.

O lodo de curtume é um resíduo industrial que pode ser aproveitado de forma pura ou associado a outros resíduos, como na produção de substratos de plantas cultivadas. Neste sentido, o objetivo desse trabalho foi avaliar a composição de substrato para a produção de mudas de café conilon, variando doses crescentes de lodo de curtume. O delineamento utilizado foi em blocos casualizados, com quatro tratamentos, sendo três doses crescentes de lodo e um tratamento convencional. As mudas foram avaliadas em relação aos parâmetros relacionados ao funcionamento do fotossistema II e a biometria. Os resultados indicam que substratos compostos por lodo, húmus e terra de subsolo promoveram, em geral, melhoria no crescimento das mudas quando comparados aos substratos convencionais, destacandose o índice de qualidade de Dickson. Os parâmetros de fluorescência e estimativas do teor de clorofila não foram afetados pela utilização do lodo de curtume na mistura para formulação de substrato de mudas de café conilon.

The Effect of Ferrous Nano-oxide Particles on Physiological Traits and Nutritional Compounds of Soybean ( Glycine max L) Seed

ABSTRACT Soybean (Glycine max L.) seed contains amounts of protein, lipid, carbohydrate and mineral elements, which protein and lipid have been known as a main part for soybean's trade value. In this study, in order to investigate the effect of ferrous nano-oxide particles on nutritional compounds of soybean seed, an experiment with 5 treatments and 3 replications was conducted as a randomized complete block design. Treatments were 5 concentrations of ferrous nano-oxide particles including 0, 0.25, 0.5, 0.75 and 1 g L-1 which were sprayed 3 times at 4 and 8 leaves stage and pod initiation. Lipid and protein contents, fatty acids profile, some of mineral elements such as Fe, Mg, Ca and P, chlorophyll a, b and total chlorophyll content were determined. Results showed that solution containing ferrous nano-oxide particles had significant effect on nutritional compounds of soybean seed (P<0.01) compared to control. The highest content of lipid and protein (25.4 and %33.8, respectively) observed by applying 0.75 g L-1 of ferrous nano-oxide and the lowest content was also in control. Changes in the trends of fatty acids profile (palmitic, oleic, linoleic and linolenic acids), some of mineral elements (Fe, Mg, Ca and P) and chlorophyll contents were similar to lipid and protein levels which by increasing in concentration of ferrous nano-oxide from 0 to 0.75 g L-1 all measured parameters also increased, but reduction in all parameters was observed in concentration from 0.75 to 1 g L-1. In conclusion, application of 0.75 to 1 g L-1 ferrous nano-oxide had the best effect on the nutrient composition of soybean seed.

Water stress effects on chlorophyll fluorescence and chlorophyll content in sugarcane cultivars with contrasting tolerance / Efeitos do estresse hídrico na fluorescência e conteúdo de clorofila em cultivares de cana-de-açúcar com tolerância contrastante

One way to minimize the impacts caused by water deficit (WD) in agriculture is the use of tolerant cultivars. The physiological evaluation of plants through the potential quantum efficiency of photosystem II (Fv/Fm) and estimated chlorophyll content (SPAD index) can be an effective tool in the selection and recommendation of water deficit-tolerant cultivars. Within this context, the aim of this study was to evaluate the physiological responses of sugarcane cultivars classified as tolerant or susceptible to water deficit. The experiment was carried out near the city of Jaú, SP, Brazil in a greenhouse, between July and December 2013. The experimental design was completely randomized in a 4 x 2 factorial arrangement, with four replications. We studied four sugarcane cultivars: RB72454, RB855453 (prone to WD), SP81-3250 and SP83-2847 (WD-tolerant) in two water management regimes (with and without deficit). WD reduced stems dry mass of all cultivars, however, the greatest decreases were observed in susceptible cultivars to WD, where the decrease was 58.3 and 74.5% for cultivars RB855443 and RB72454, respectively. As for the SP81-3250 and SP83-2847 cultivars (tolerant), the reduction was 44.1 and 47.7%, respectively. For water deficit-tolerant cultivars, there was lower reduction in potential quantum efficiency of photosystem II and SPAD index; therefore, the physiological characteristics (Fv/Fm and SPAD index) are features that can aid the identification and selection of water deficit tolerant cultivars, and also help the recommendation of these cultivars for harsh environments, minimizing the effects of water deficit on stem yield on the sugarcane crop.

Uma forma de minimizar os impactos causados pelo déficit hídrico (DH) na agricultura é o uso de cultivares tolerantes. A avaliação fisiológica das plantas através da eficiência quântica potencial do fotossistema II (Fv/Fm) e do índice SPAD pode se tornar uma ferramenta eficiente na seleção e recomendação de cultivares tolerantes ao déficit hídrico. Com base nesse contexto, o objetivo deste trabalho foi avaliar as respostas fisiológicas de cultivares de cana-de-açúcar classificadas como tolerantes e susceptíveis ao déficit hídrico. O experimento foi realizado na região do município de Jaú/SP/Brasil em casa de vegetação, entre os meses de julho e dezembro de 2013. O delineamento experimental foi inteiramente casualizado no esquema fatorial 4 x 2, com quatro repetições. Foram estudadas quatro cultivares de cana-de-açúcar: RB72454, RB855453 (susceptíveis ao DH), SP81-3250 e SP83-2847 (tolerantes ao DH) em dois regimes hídricos (com e sem déficit). O DH reduziu a massa seca dos colmos de todas cultivares, porém, as maiores quedas foram observadas nas cultivares susceptíveis ao DH, em que nas cultivares RB855443 e RB72454 a queda foi de 58,3 e 74,5%, respectivamente. Já para as cultivares SP81-3250 e SP83-2847 (tolerantes), a redução foi de 44,1 e 47,7%, respectivamente. As cultivares tolerantes ao déficit hídrico tiveram menor redução na eficiência quântica potencial do fotossistema II e no índice SPAD, demonstrando, portanto, que os parâmetros fisiológicos (Fv/Fm e índice SPAD) são características que podem auxiliar a identificação e seleção de cultivares tolerantes ao déficit hídrico, e ainda, auxiliar a recomendação dessas cultivares para ambientes desfavoráveis, minimizando os efeitos do déficit hídrico sobre o rendimento de colmos na cultura da cana-de-açúcar.

Lanthanum content and effects on growth, gas exchanges, and chlorophyll index in maize plants / Teor de lantânio e efeitos no crescimento, trocas gasosas e teor de clorofila em plantas de milho

Rare earth elements, such as lanthanum (La), have been applied to agriculture via fertilizers, aiming to increase the productivity and crop quality, such results observed mainly in China. However, the knowledge about the effect of La on maize growth, as well as for other species, despite the growing interest it is still limited. The aim of this study was to evaluate the effects of La on maize growth, La content,photosynthetic rate and chlorophyll content in maize plants in response to La treatment (0, 25, 50, 100, 150, 300 and 600 μM) in nutrient solution for three weeks. The plants were placed in geminated pots using a split-root technique. One of the pots in the geminated set was filled with a complete nutrient solution without La, while another was filled with a nutrient solution without phosphorus but containing different concentrations of La. It was verified that roots of maize plants can accumulate approximately sixty percent more La than shoots. Moreover, low La concentrations stimulated an increase in chlorophyll index,resulting in a slight increase in shoot biomass. At higher levels, La didn’t reduce growth but caused adecrease in both photosynthetic rate and chlorophyll index.

Elementos terra rara, como lantânio (La), são aplicados à agricultura via fertilizantes, com oobjetivo de aumentar a produtividade e a qualidade das culturas agrícolas, fato observado principalmente naChina. Entretanto, o conhecimento sobre o efeito de La no crescimento do milho, bem como para outrasculturas agrícolas, ainda é limitado apesar do interesse crescente. O presente estudo objetivou avaliar oefeito da aplicação de La sobre o crescimento, teor de La, fotossíntese e teor de clorofila em plantas demilho, expostas a concentrações crescentes de La (0, 25, 50, 100, 150, 300 e 600 μM) em solução nutritivapor três semanas. As plantas foram colocadas em vasos geminados usando uma técnica de raiz divisória.Um dos potes no conjunto geminado foi preenchido com solução nutritiva completa que não continha La,enquanto outra foi preenchida com solução nutritiva sem fósforo, mas contendo diferentes concentraçõesde La. Foi verificado que as raízes das plantas de milho podem acumular sessenta por cento mais La quandocomparado à parte aérea. Além disso, as baixas concentrações de La estimularam o aumento do teor declorofila, resultando em um aumento na biomassa da parte aérea. Em concentrações mais elevadas, aaplicação de La não reduziu o crescimento das plantas de milho, mas causou diminuição na taxafotossintética e no índice de clorofila.

Physicochemical characterization and antioxidant activity of decolorized Moringa oleifera Lam leaf flour

BACKGROUND: Maringa oleifera leaves are rich in antioxidant substances; however, when lyophilized leaves were used in flour form in meat products, they presented no antioxidant effect and even accelerated the oxidation process of the product. Thus, the objective of this study was to evaluate the effect of chlorophyll extraction on the physicochemical composition and antioxidant activity of Moringa leaves. METHODS: Moringa leaves were dried and ground in order to obtain uniform flour. A treatment using chlorophyll extraction (decolorized) was tested versus a control treatment(non-decolorized) for proximate composition, instrumental color, and antioxidant activity using ANOVA followed by Tukey'stest. RESULTS: Higher crude fiber, ash, and protein contents were observed for decolorized flour (19.41 and 38.13%, 11.87 and14.02%, and 28.81 and 31.33%, respectively) when compared to those for the control. Chlorophyll extraction significantly affected (p< 0.05) the instrumental color of the leaves flour. The half maximal effective concentration (EC50) of both decolorized and control flour was 3.74 and 4.30 mg/L, respectively. The equivalent of antioxidant per gramof non-decolorized leaves was higher than that observed for the decolorized leaves (0.36 and 0.32 g/g DPPH, respectively). The antioxidant activity (AA%) of the extract from non-decolorized leaves was higher in the concentrations of 5 and 2.5 mg/0.1 mL, while the decolorized leaves was higher in the extract concentration 5 and 2 mg/0.1 ml. CONCLUSION: The decolorization process affected the chemical composition and color of Moringa oleifera leaves flours however did not improve its antioxidant activity