Abstract Introduction: Crassocephalum crepidioides (Asteraceae) is an herbaceous species with outstanding ethnobotanical uses in Africa and elsewhere, that has extended invasively in several tropical and subtropical regions around the world. Objective: To identify the chemical composition of the essential oils of C. crepidioides, to observe and measure phenological parameters (growth and development), and to record signs of the interaction of plants with other biotic agents throughout the life cycle in the Central Valley of Costa Rica. Methods: The essential oils were obtained via hydrodistillation in a Clevenger-type apparatus. The chemical composition of the oils was done by capillary gas chromatography (GC/FID and GC/MS). The biological field study was a descriptive account of phenological patterns observed during a year in 45 plants from three places, including vegetative and reproductive phases. Results: The essential oils consisted mainly of terpenoids (91,0 to 98,6%). A total of 231 different compounds were identified in the analyzed samples, corresponding to 94,9- 99,3% of the total amount of the oils. The major compounds from the leaf oil were myrcene (67,5%) and β- phellandrene (11,6%), while the stem oil mainly contained myrcene (42,2%) and α-copaene (16,5%). The major constituents of flower oil were myrcene (71,8%) and β- phellandrene (17,2%). In the root oil, (E)-β-farnesene (29,5-46,0%), (Z)-β-farnesene (13,0-15,7%) and (E)-caryophyllene (6,0-6,1%) predominated. The mean height of plants was considerably superior in open and sunny places compared to values in partially shaded habitats. In one of the places, 36% of plants died before completing the life cycle for the most part, due to herbivory that was present in more than 80% of all plants and damaged 100% of their shoot organs (stems, leaves, lateral buds, flower buds, and flowers). November and December were the months with maximal flower anthesis and fruit ripening. Conclusions: This species is recognized as annual, but 2/3 of plants completed their life cycle in 4 to 6 months, and due to herbivory and other environmental factors its propagation shows a considerable reduction.

Resumen Introducción: Crassocephalum crepidioides (Asteraceae) es una especie herbácea con notables usos etnobotánicos en África y otras áreas, que se extendió como invasora en varias regiones tropicales y subtropicales del mundo. Objetivo: Determinar la composición química de los aceites esenciales de C. crepidioides (planta entera, hojas, tallos, flores y raíces), observar y medir parámetros fenológicos (crecimiento y desarrollo) y registrar indicios de interacción de las plantas con otros agentes bióticos a lo largo del ciclo de vida en el Valle Central de Costa Rica. Métodos: La extracción de los aceites se realizó mediante el procedimiento de hidrodestilación, usando un equipo Clevenger modificado. La composición química de los aceites se obtuvo mediante técnicas cromatográficas (GC/FID y GC/MS), el cálculo de los índices de retención en dos columnas de polaridad diferente y mediante los espectros de masa de cada constituyente. El estudio biológico de campo fue un registro descriptivo de patrones fenológicos observados durante un año en 45 plantas de tres sitios, abarcando las fases vegetativa y reproductiva. Resultados: Los aceites esenciales están constituidos principalmente por terpenoides (91,0- 98,6%). Se identificaron en total 231 compuestos diferentes en todas las muestras analizadas, correspondientes a un 94,9-99,3% de los constituyentes totales. Los compuestos mayoritarios de los aceites de las hojas fueron mirceno (67,5%) y β-felandreno (11,6%), mientras que los aceites de los tallos registraron principalmente mirceno (42,2%) y α-copaeno (16,5%). Los constituyentes mayoritarios del aceite de las flores fueron mirceno (71,8%) y β-felandreno (17,2%). En los aceites de las raíces predominaron (E)-β-farneseno (46,0-29,5%), (Z)- β-farneseno (13,0-15,7%) y (E)-cariofileno (6,0-6,1%). La altura promedio de las plantas fue considerablemente mayor en sitios abiertos y soleados que en sitios parcialmente umbrosos. En sitios abiertos las hojas superiores desarrollaron lóbulos laterales profundos, que fueron nulos o raros en sitios sombreados. En uno de los sitios 36% de plantas murió antes de completar el ciclo de vida, principalmente por herbivoría, que afectó más de 80% de todas las plantas y dañó 100% de órganos del vástago. Noviembre y diciembre fueron los meses con máxima antesis floral y maduración de frutos. Conclusiones: Esta especie se reconoce como anual, pero 2/3 de las plantas observadas completaron su ciclo de vida en 4 a 6 meses y, debido a herbivoría y otros factores ambientales, su propagación se ha reducido notablemente.

Resumen Introducción: Hamadryas feronia feronia, se mimetiza sobre las cortezas de los árboles y suele emitir sonidos al volar que llaman la atención; posee un buen potencial para los bionegocios (exportación, elaboración de artesanías y centros turísticos de crianza). Sin embargo, aún se desconocen sus aspectos biológicos que obstaculizan su crianza en cautiverio. Objetivos: Determinar los aspectos biológicos de alimentación, comportamiento de oviposición, ciclo de vida y los enemigos naturales de Hamadryas feronia feronia L. en San Rafael-Indiana, Loreto, Perú. Métodos: Los muestreos fueron realizados desde enero 2018 a diciembre 2019 en la comunidad de San Rafael, río Amazonas. Los adultos fueron observados durante el día, se registraron sus plantas alimenticias, su comportamiento de oviposición, su ciclo biológico y sus enemigos naturales. El ciclo de vida fue evaluado en el laboratorio, utilizando 20 huevos recientemente depositados en las hojas de su planta hospedera. Resultados: Las larvas de H. feronia feronia se alimentan de las hojas de Dalechampia juruana y los adultos se alimentan de la savia de la corteza de los árboles de Cedrela odorata, Spondias mombin, Uncaria guianensis y de los frutos fermentados de Syzygium malaccense y Pouteria caimito. Los adultos vuelan en días soleados, los machos emiten un fuerte sonido al volar. Las hembras previo a la oviposición revolotean de forma irregular alrededor de su planta hospedera entre las 8.00 y las 14.00 h y depositan sus huevos en el haz y envés de las hojas de forma aislada con mayor frecuencia en el envés (N= 85). La duración del ciclo, desde huevo hasta adulto fue de 28.24 días. El periodo promedio del huevo fue 3.75 ± 0.40 días. La larva pasa por cinco estadíos larvales: el primero duró 3.21 ± 1.03 días, el segundo 2.78 ± 0.73 días, el tercero 2.67 ± 0.77 días, el cuarto 3.22 ± 0.81 días, y el quinto 4.61 ± 0.70 días. El periodo de la prepupa duró 1.33 ± 0.49 días y el de pupa 6.67 ± 0.80 días; los adultos nacieron entre las 10:00 y 11:00 h. Los machos adultos viven en promedio 31.80 ± 3.29 días, la hembra 42.00 ± 2.14 días y sus huevos son parasitados por un microhimenóptero (Scelionidae). Conclusiones: Este estudio permitió conocer los aspectos biológicos de H. feronia feronia identificando sus plantas alimenticias tanto de las larvas como de los adultos, su comportamiento de oviposición, así mismo se ha determinado que tiene un ciclo biológico relativamente corto con un periodo menor de un mes y sus huevos son consumidos por un pequeño Himenóptero que puede obstaculizar su producción. Este trabajo brinda información necesaria para desarrollar la crianza de H. feronia feronia, orientado a su conservación, la educación ambiental y los bionegocios (turismo y artesanía) en la Amazonia peruana.

Abstract Introduction: Hamadryas feronia feronia, which mimics the bark of trees and often makes attention-grabbing sounds when flying, has good potential for bio-business (export, handicrafts and tourist breeding centers). However, its biological aspects are still unknown, which hinder its captive breeding. Objectives: To determine the biological aspects of feeding, oviposition behavior, life cycle and natural enemies of Hamadryas feronia feronia L. in San Rafael-Indiana, Loreto, Peru. Methods: Sampling was conducted from January 2018 to December 2019 in the community of San Rafael, Amazon River. Adults were observed during the day, their food plants, oviposition behavior, biological cycle and natural enemies were recorded. The life cycle was evaluated in the laboratory, using 20 eggs recently deposited on the leaves of their host plant. Results: The larvae of H. feronia feronia feed on the leaves of Dalechampia juruana and the adults feed on the bark sap of Cedrela odorata, Spondias mombin, Uncaria guianensis and the fermented fruits of Syzygium malaccense and Pouteria caimito. Adults fly on sunny days, males emit a loud sound when flying. Females prior to oviposition flit irregularly around their host plant between 8.00 and 14.00 h and deposit their eggs on the upper and underside of leaves in isolation, most frequently on the underside. The duration of the cycle from egg to adult was 28.24 days. The average egg period was 3.75 ± 0.40 days. The larvae passed through five larval instars: the first instar 3.21 ± 1.03 days, the second 2.78 ± 0.73 days, the third 2.67 ± 0.77 days, the fourth 3.22 ± 0.81 days, and the fifth 4.61 ± 0.70 days. The prepupal period lasted 1.33 ± 0.49 days and the pupal period 6.67 ± 0.80 days; the adults hatched between 10:00 to 11:00 h. Adult males lived on average 31.80 ± 3.29 days, the female 42.00 ± 2.14 days and their eggs were parasitized by a microhymenopteran (Scelionidae). Conclusions: This study allowed to know the biological aspects of H. feronia feronia identifying its food plants of both larvae and adults, its oviposition behavior, as well as it has been determined that it has a relatively short biological cycle with a period of less than one month and its eggs are consumed by a small Hymenoptera that can hinder its production. This work provides necessary information to develop the breeding of H. feronia feronia, oriented to its conservation, environmental education and biotrade (tourism and handicrafts) in the Peruvian Amazon.

Resumen Introducción: El integumento de los moluscos terrestres es susceptible a desecación, por eso la selección de microhábitats, la estacionalidad y el comportamiento a lo largo del día son cruciales para su sobrevivencia. No obstante, es poco lo que se ha investigado al respecto, en especial para moluscos tropicales de arbustos del sotobosque en bosques húmedos de montaña. Objetivo: Analizar los patrones de actividad y de la selección de microhábitats del caracol terrestre Tikoconus costarricanus según la estación del año, la hora del día y el clima. Métodos: El trabajo lo realicé en un bosque tropical húmedo de montaña cerca de la represa hidrológica “El Llano”, Costa Rica. Analicé la actividad diaria de especímenes de T.costarricanus en un trayecto de 2 km: observé 167 especímenes e hice 781 observaciones. Tomé nota de: estación del año, hora, actividad, parte de la hoja donde estaba el caracol, altura en la planta, clima y humedad relativa y temperatura dentro del bosque. Consideré que un espécimen estaba activo cuando los tentáculos ópticos estaban extendidos. Analicé la precipitación pluvial por horas con datos de una estación meteorológica cercana. Resultados: Encontré caracoles principalmente en las hojas de arbustos entre 1.1 y 2 m sobre el suelo; encontré individuos activos a todas horas y en cualquier época del año. Solo el 24 % de los individuos estaban en el haz, de esos el 92 % estaban activos. Encontré variación estacional en el patrón de actividad, la selección del lado de la hoja de acuerdo a la hora del día y el clima, la cantidad de especímenes estivando, y la distribución vertical. En la época seca encontré más caracoles activos con clima húmedo, por el contrario, en la estación lluviosa encontré más caracoles activos con clima seco. Durante las horas de luz de la estación lluviosa, la cantidad de caracoles activos sobre el haz de las hojas disminuyó con el aumento de precipitación pluvial, en tanto que en la estación seca disminuyó con el aumento de la temperatura y la disminución de la humedad relativa. Durante las horas nocturnas de ambas estaciones, la cantidad de caracoles sobre el haz de las hojas disminuyó considerablemente en relación a los caracoles activos, especialmente en la época lluviosa. Este caracol estivó principalmente a mediodía y en las tardes de la época seca en el envés de las hojas por periodos inferiores a 21 h seguidas. La elevada humedad del bosque tropical húmedo de montaña permite que estos caracoles estén activos en cualquier momento. Sin embargo, la estivación les permite protegerse de la desecación durante los periodos más secos. El patrón de lluvias durante las horas de luz de la época lluviosa explica la disminución de especímenes presentes en el haz de las hojas, pero en la época seca lo explica mejor el aumento de la temperatura y la disminución de la humedad relativa. Durante las horas oscuras, la casi ausencia de caracoles en el haz de las hojas durante la estación lluviosa se explica si al patrón de lluvia se le agrega el efecto del goteo foliar producido por la lluvia y el rocío que se condensa sobre las hojas. La situación es un poco diferente en las horas oscuras de la estación seca, en este caso, la disminución de caracoles en el haz, se explica por el goteo foliar derivado del rocío y de la precipitación de neblina. Es posible que la diferencia en la preferencia vertical se deba a que evitan la lluvia y la salpicadura de la lluvia al caer en el suelo. Conclusiones: La humedad, la temperatura, la lluvia y el goteo foliar derivado de rocío, neblina y lluvia, afectan el comportamiento y la selección de sustrato de moluscos terrestres pequeños que habitan en arbustos de bosques tropicales húmedos de montaña.

Abstract Introduction: The integument of terrestrial mollusks is highly susceptible to dehydration; therefore, microhabitat selection, seasonality and behavior around the day are crucial to their survival. However, they are still poorly understood, especially for tropical montane wet forest species. Objetive: To analyze activity patterns and microhabitat selection on shrubs of the land snail Tikoconus costarricanus, according to season, daytime and weather. Methods: I conducted the study near “El llano” water dam in a tropical montane wet forest in Costa Rica. I observed daily activity of T. costarricanus, during the rainy and the dry season on a 2 km long trail. I observed 167 specimens and made 781 observations in total. I took note of: season, time, activity, weather, temperature and relative humidity inside the forest, and part of the leaf and height where snails were. Active snails had optical tentacles extended. I analysed daily rainfall data from a nearby meteorological station. Results: This species can be found mainly on understory leaves between 1.1 and 2 m above the floor. They are active the day around during the whole year. Only 24 % of the snails were on the upper side of leaves, but 92 % of them were active. The following behaviors were season dependent: activity peaks, leaf side selection according to daytime and weather, quantity of snails aestivating and vertical distribution. During the dry season, I found more active snails in rainy and cloudy days. During the rainy season I found more active snails in sunny days. During rainy season light hours, active snail percentage on the upper side of leaves decreased with rainfall increase, while in the dry season decreased with temperature increase and relative humidity decrease. During night hours of both seasons, the number of snails on the upper side of leaves decreased considerably in relation to active snails, especially in the rainy season. This snail aestivated on the underside of leaves during periods shorter than 21 h, mainly around noon and afternoons during the dry season. High humidity in this forest allowed snail activity around the day at any season. However, this species aestivated when moisture reached the lowest values, mainly, around noon and in the afternoons in the dry season. The rainfall pattern during the rainy season light hours explains the specimen decrease on the upper side of leaves, but in the dry season it is better explained by the temperature increase and the decrease in relative humidity. During dark hours, the almost complete snail absence on the upper side of leaves during the rainy season is explained if the effect of canopy drip produced by rain and dew condensed on leaves is added to the rain pattern. The situation is slightly different in dark hours of the dry season, in this case, snail decrease on the upper side of leaves is explained by canopy drip from dew and fog precipitation. Seasonal difference in vertical distribution may be a way to avoid rain and rain splash out on the soil. Conclusions: Moisture, temperature, rain, and canopy drip from dew, fog and rain, affect behavior and substrate selection of small terrestrial mollusks that inhabit shrubs in wet tropical rainforests.

Abstract Objective To characterize the variations in the phenol content in the different edible and non-edible portions of Elaeagnus angustifolia L. during the growth cycle of the plant. Materials and Methods Plant material was collected during the plant growth cycle in the Valle Medio region, Río Negro, Argentina. The collection was carried out in five sampling moments (September, November, January, February and March). For such purpose, samples were taken from the leaves, flowers and fruits of the canopy exposed to the sun and leaves in the shaded canopy. The presence of polyphenols in the different samples collected by qualitative and quantitative essays was evaluated. The data were analyzed through variance analysis; while the significant differences among means, by Tukey’s test for p < 0,05. The statistical program Infostat® was applied. Results Significant differences (p < 0,05) were found in the content of polyphenols between the external sunlit sunny leaves and the inner shaded ones in the September sampling. The shaded leaves contained significantly more phenolic compounds than the higher sunlit sunny leaves (19,8 and 16,4 mg GAE g-1 DM, respectively). This variability becomes null, when the total edible thyrse is compared with the non-consumed parts. Conclusions Seasonal and spatial variation was determined in the concentration of total phenols in the edible and non-edible biomass of E. angustifolia during its growth cycle. In addition, no limiting quantities of polyphenols were found in the shaded leaves, which could reduce the voluntary intake of feed and its digestibility.

Resumen Objetivo Caracterizar las variaciones en el contenido de fenoles en las diferentes porciones comestibles y no comestibles de Elaeagnus angustifolia L. durante el ciclo de crecimiento de la planta. Materiales y Métodos Se recolectó material vegetal durante el ciclo de desarrollo de la planta en la región del Valle Medio, Río Negro, Argentina. La recolección se realizó en cinco muestreos (septiembre, noviembre, enero, febrero y marzo). Para ello se tomaron muestras de las hojas, las flores y los frutos de la canopea expuesta al sol y de las hojas sombreadas. Se evaluó la presencia de polifenoles en las diferentes muestras recolectadas mediante ensayos cualitativos y cuantitativos. Los datos se analizaron mediante análisis de varianza, mientras que las diferencias significativas entre las medias por medio de la prueba de Tukey, para p < 0,05. Se aplicó el programa estadístico Infostat®. Resultados Se encontraron diferencias significativas (p < 0,05) en el contenido de polifenoles entre las hojas externas soleadas y las interiores sombreadas en el muestreo de septiembre. Las hojas sombreadas contenían significativamente más compuestos fenólicos que las hojas superiores soleadas (19,8 y 16,4 mg EAG g-1 de MS, respectivamente). Esta variabilidad se vuelve nula, cuando se compara el tirso comestible total con las partes no consumidas. Conclusiones Se determinó la variación estacional y espacial en la concentración de fenoles totales en la biomasa comestible y no comestible de E. angustifolia durante su ciclo de crecimiento. Además, no se encontraron cantidades limitantes de polifenoles en las hojas sombreadas, que pudieran reducir el consumo voluntario de alimento y su digestibilidad.

RESUMO: Descreve-se a reprodução experimental da intoxicação cianogênica por grama estrela (Cynodon nlemfuensis vanderyst var. nlemfuensis cv. ‘Florico’) em bovinos. A grama estrela foi plantada em quatro piquetes em área sombreada (1, 2, 3 e 4) e em três piquetes em área ensolarada (5, 6 e 7) e foram adubados com o equivalente a 0, 750, 200 ou 100kg/ha de ureia. Folhas da planta foram coletadas de cada piquete e imediatamente fornecidas na dose de 10g/Kg de peso vivo para 8 bezerros com idades entre 5 meses a 1 ano. Exames clínicos foram realizados antes e durante fornecimento da planta. Folhas verdes de estrela africana foram submetidas ao teste do papel picro-sódico para verificar a presença de ácido cianídrico e ao teste da difenilamina para avaliar a concentração de nitrato. Sinais clínicos de intoxicação pela grama estrela cv. “Florico” nos bovinos foram observados entre 5 e 15 minutos após o término da ingestão, estes incluíram andar cambaleante, tremores musculares, micção frequente e/ou em gotejamento, taquicardia, atonia ruminal, depressão, mucosas oculares e sangue venoso de coloração vermelho-vivo. Três animais adoeceram gravemente, quatro manifestaram sinais clínicos leves a moderados e um não adoeceu. Os 3 bovinos que adoeceram gravemente receberam solução de tiossulfato e nitrito de sódio na dose de 40ml/100kg de peso vivo, por via endovenosa (IV). Grama estrela florico produziu intoxicação em bovinos e a reação ao teste do papel picro-sódico e difenilamina foi mais significativa para as amostras cultivadas à sombra e com alta adubação nitrogenada. Utilização de grama florico deve ser evitada em sistema silvipastoril.

ABSTRACT: We experimentally reproduced star grass (Cynodon nlemfuensis Vanderyst var. nlemfuensis cv. “Florico”) poisoning in cattle. Star grass was planted in four shaded (1, 2, 3, and 4) and three sunny paddocks (5, 6, and 7) and were fertilized with the equivalent of 0, 750, 200, or 100 kg/ha urea. Fresh plant leaves were collected from each paddock and fed to 8 calves aged 5 months to 1 year at 10g/kg live weight. Clinical examinations were performed pre- and post-feeding. Fresh leaves were also subjected to sodium picrate paper and diphenylamine tests to evaluate hydrocyanic acid and nitrate concentration, respectively. Clinical signs of poisoning by the star grass cv. “Florico” in cattle were observed 5-15 minutes after ingestion; these included wobbling, muscle tremors, frequent and/or dripping urination, tachycardia, ruminal atony, depression, red ocular mucous membranes, and bright red venous blood. Three animals became severely ill, 4 manifested mild to moderate clinical signs, and 1 did not become ill. The 3 severely ill bovines received a thiosulfate and sodium nitrite solution at a dose of 40ml/100 kg live weight, intravenously (IV). Florico star grass poisoned bovines and the reaction to the sodium picrate paper and diphenylamine tests was more significant for samples cultivated in the shade and with high nitrogen fertilization. Florico grass utilization should be avoided in a silvopastoral system.

Abstract The quantification and expression of genes related to flowering is an important tool to understand this process. Studies carried out in Arabidopsis ssp. have served as a basis for molecular studies in fruit trees. The objective was to quantify the expression of the gene flowering locus T (MiFT) in ‘Ataulfo’ mango and its relationship with environment and growth regulators. Two experiments were carried out: 1) trees with 2 500 mg L-1 of paclobutrazol (PBZ) were applied in a single application (1X) at 30 days after pruning (ddp). The mature leaves were collected from September to December 2013 and January to February 2014 under sunny and shaded conditions. Experiment 2: growth regulators, PBZ (2 500 mg L-1, 1X), calcium prohexadione (P-Ca) (500 mg L-1, 3X) and gibberellic acid (250 mg L-1, 1X) were applied. The expression MiFT was quantified, the number and type of growth emerged in flowering, temperature and precipitation were evaluated. The experimental design was completely randomized with factorial arrangement in experiment 1 and completely randomized in experiment 2. MiFT was expressed in all sampled months, the expression varied from 0.3 to 31.4%. On the other hand, when evaluating the expression of the gene with respect to the orientation of the outbreak, the results were 0.081% on the shaded side and 12% on the sunny side. Sunny shoots had the highest flowering ptercentage (66%). MiFT was expressed in leaves treated with PBZ and P-Ca, the highest expression was in December, cooler month, with 4.7 and 30.3%, respectively, which favored flowering. Gibberellins inhibited the expression of the gene and therefore flowering.

Resumen La cuantificación y expresión de genes relacionados con floración constituye una herramienta importante para entender este proceso. Trabajos realizados en Arabidopsis spp. han servido como base para estudios moleculares en frutales. El objetivo fue cuantificar la expresión del gen flowering locus T (MiFT) en mango ‘Ataulfo’ y su relación con ambiente y reguladores de crecimiento. Se llevaron a cabo dos experimentos: 1) se aplicaron árboles con 2 500 mg L-1 de paclobutrazol (PBZ) en una sola aplicación (1X) a 30 días después de la poda (ddp). Se colectaron hojas maduras de septiembre a diciembre 2013 y enero a febrero 2014 bajo condiciones de sol y sombreadas. Experimento 2: se aplicaron reguladores de crecimiento, PBZ (2 500 mg L-1, 1X), Prohexadiona de calcio (P-Ca) (500 mg L-1, 3X) y ácido giberélico (250 mg L-1, 1X). Se cuantificó la expresión MiFT, se evaluó el número y tipo de crecimiento emergido en floración, temperatura y precipitación. El diseño experimental fue completamente al azar con arreglo factorial en experimento 1 y completamente al azar en el experimento 2. MiFT se expresó en todos los meses muestreados, la expresión varió de 0.3 hasta 31.4%. Por otra parte, al evaluar la expresión del gen con respecto a la orientación del brote, los resultados fueron de 0.081% el lado sombreado y 12% el soleado. Brotes soleados presentaron el mayor porcentaje de floración (66%). MiFT se expresó en hojas tratadas con PBZ y P-Ca, la mayor expresión fue en diciembre, mes más frío, con 4.7 y 30.3%, respectivamente, lo que favoreció floración. Giberelinas inhibió la expresión del gen y por ende floración.

Resumo Ipê amarelo é uma árvore nativa da floresta Atlântica brasileira, encontrada em uma ampla distribuição latitudinal. Neste estudo, nós investigamos os efeitos potenciais de alterações de curto prazo nas condições micro-climáticas sobre características estruturais, proteína e carboidratos histoquimicamente marcados, de folhas de ipê amarelo, usando estratégias de análise estrutural e histoquímicas. As folhas foram marcadas em quatro condições microclimáticas distintas: 1. Tarde, após um dia quente e ensolarado; 2. Amanhecer, após um dia quente e ensolarado; 3. Ao meio-dia, de um dia quente e ensolarado; e 4. Ao meio-dia, de um dia frio e nublado. Folíolos expostos à baixa irradiância luminosa apresentaram cloroplastos achatados, uniformemente distribuídos no interior das células, por todo o parênquima paliçádico, enquanto que folíolos expostos à alta irradiância apresentaram cloroplastos achatados e arredondados, nas células superiores e inferiores do parênquima paliçádico, respectivamente. A marcação mais intensa para proteína foi observada para folhas coletadas no momento mais frio de coleta, enquanto que a marcação mais fraca foi observada para folhas coletadas após um dia quente e ensolarado. Os grãos de amido maiores e mais numerosos foram observados em folhas coletadas durante a tarde de dia quente e ensolarado, enquanto que os menores e menos numerosos grãos de amido foram observados em folhas coletadas ao amanhecer.

Abstract Golden trumpet, Tabebuia chrysotricha, is a native tree from the Brazilian Atlantic rain forest, with a broad latitudinal distribution. In this study, we investigated the potential effects of short-term changes in micro-weather conditions on structural features, and total protein and carbohydrate content of golden trumpet leaves, using structural and histochemical approaches. Leaves were harvested in four different micro-weather conditions: 1. Afternoon, after a hot, sunny day; 2. at dawn, after a previously hot, sunny day; 3. at noon, of a hot, sunny day; and 4. at noon, of a cold, cloudy day. Leaflets exposed to low light irradiance showed flattened chloroplasts, uniformly distributed within the cells, throughout the palisade parenchyma. Conversely, leaflets exposed to high light irradiance presented flattened and rounded chloroplasts, in the upper and lower palisade parenchyma cells, respectively. The strongest protein staining was found for leaves harvested at the coldest period, whereas the weakest protein staining was found for leaves harvested after a hot, sunny day. The largest and most numerous starch grains were found for leaves harvested in the afternoon, after a hot, sunny day. Conversely, the smallest and less numerous starch grains were found for leaves harvested at dawn. Analysis of the data reported herein suggests that the leaflet responses to transient changes in micro-weather conditions are likely to contribute to the golden trumpet successful establishment in the broad latitudinal distribution in which the species is found.

ABSTRACT For pioneer plants, shaded habitats represent a stressful condition, where sunlight exposure is below the optimum level and so leaves expand in order to intercept a greater amount of light. We investigated changes in both phenotypic variation and stress of Bauhinia brevipes in sunny and shaded microhabitats. Leaf area was used as a measure of phenotypic variation, whereas leaf asymmetry (difference between right and left sides of leaves), was used as a measure of stress. We hypothesized an increase in leaf area and stress in shaded locations, which might indicate that B. brevipes was compensating for low light absorption, and elevated levels of stress, respectively. Plants in the sun fitted a fluctuating asymmetry pattern (normal distribution of right minus left sides), while shaded plants were clearly antisymmetric (bimodal distribution of leaf side differences). Leaf asymmetry and area were 5% and 26.8% higher in plants in the shade compared to plants in the sun, respectively. These results were expected since B. brevipes is found predominantly in open areas; so sunlight exposure is important for its development. The presence of antisymmetry is rare in studies of developmental instability, and here it might indicate higher stress compared to plants with fluctuating asymmetry.

En un ecotono de bosque atlántico y Caatinga, ubicado en el Parque Nacional Serra de Itabaiana, Sergipe, Brasil, fueron estudiadas las formas de uso de recursos espaciales y temporales de dos espécies simpátricas de Ameivula El estudio se realizó entre febrero de 2008 y enero de 2009. El método adoptado fue la búsqueda activa con control de tiempo, en el periodo de las 06:00-18:00 horas. Se observó que la especie con más registros fue A. ocellifera. A pesar del alto solapamiento de nicho temporal observado (Ojk = 0,90), A. ocellifera y A. abaetensis difirieron en relación con los momentos de mayor actividad. A. ocellifera se observó con mayor frecuencia (≥ 10 %) 08:00-13:00, mientras que A. abaetensis de 09:00 a 13:00 horas. Ambas especies fueron más frecuentes en los días soleados, con patrones similares de actividad en el momento de la observación, fueron vistas por lo general caminando sobre la arena (A. ocellifera) o en las hojas cerca de la base de arbustos (A. abaetensis). Conductas adoptadas por las dos especies Ameivula en respuesta al enfoque del observador eran diferentes y estaban relacionados con el grado de exposición de la vulnerabilidad a la depredación. La coexistencia de A. ocellifera y A. abaetensis en el área de estudio se relaciona posiblemente con pequeñas diferencias en el patrón de tiempo de uso de los recursos y el espacio de las dos especies, estas diferencias son probablemente el resultado de las interacciones ecológicas actuales. Los resultados obtenidos en este estudio contribuyen a la comprensión de la historia natural y ecología de las especies de Ameivula y generan principalmente información útil para la conservación de estas especies en hábitats de transición de la Mata Atlántica-Caatinga.

The forms of spatial and temporal resources use of two sympatric species of Ameivula were studied in an Atlantic Forest-Caatinga ecotone located in Parque Nacional Serra de Itabaiana, Sergipe, Brazil. The study was conducted between February 2008 and January 2009. The method used was an active search for a limited time, from 06:00 am to 06:00 pm. The species were observed during all months sampled, and A. ocellifera presented the highest number of sightings. Despite the high temporal niche overlap observed (Ojk = 0.90), A. ocellifera and A. abaetensis differed regarding the times of higher activity. A. ocellifera was most seen (≥ 10%) between 08:00 am and 01:00 pm, and A. abaetensis from 09:00 am to 01:00 pm. Both species were found more frequently on sunny days, with similar patterns of activity at the time of sighting, being usually observed walking on sand (A. ocellifera) or leaves near the base of shrubs (A. abaetensis). The behaviors demonstrated by both species of Ameivula in response to the approach of the observer were different and were related to the level of exposure along with the vulnerability to predation. The coexistence of A. ocellifera and A. abaetensis in the study area is possibly related to minor differences in the use pattern of temporal and spatial resources by both species, and these differences are probably due to the current ecological interactions. The results obtained in this study contribute to the understanding of the natural history and ecology of the species of Ameivula and mainly generate useful information for the conservation of these species in habitats transitional of Atlantic Forest-Caatinga.

As formas de utilização dos recursos espaciais e temporais por duas espécies simpátricas de Ameivula foram estudadas em um ecótono de Mata Atlântica e Caatinga, situado no Parque Nacional Serra de Itabaiana, Sergipe, Brasil. O estudo foi desenvolvido entre fevereiro de 2008 e janeiro de 2009. O método adotado foi o de busca ativa limitado por tempo, sendo utilizado o período das 06:00 às 18:00 h. As duas espécies foram verificadas ao longo de todos os meses de coleta, sendo A. ocellifera a com maior número de registros. Apesar da alta sobreposição de nicho temporal observada (Ojk = 0,90), A. ocellifera e A. abaetensis diferiram em relação aos horários de maior atividade. A. ocellifera foi avistado com maiores frequências (≥10 %) entre 08:00 e 13:00 h, enquanto que A. abaetensis, entre as 09:00 às 13:00 h. As duas espécies foram mais frequentes em dias ensolarados, com padrões similares de atividade no momento do avistamento, tendo as mesmas sido verificadas, em geral, andando sobre areia (A. ocellifera) ou folhas próximas à base de arbustos (A. abaetensis). Os comportamentos adotados pelas duas espécies de Ameivula em resposta à aproximação do observador foram diferenciados e estiveram relacionados ao grau de exposição e, consequentemente, de vulnerabilidade à predação. A coexistência de A. ocellifera e A. abaetensis na área de estudo está possivelmente relacionada a pequenas divergências no padrão de uso de recursos temporais e espaciais pelas duas espécies, sendo provavelmente essas diferenças resultantes de interações ecológicas atuais. Os dados obtidos neste estudo contribuem para o conhecimento sobre a história natural e ecologia das espécies de Ameivula e, principalmente, geram informações úteis para a conservação destas espécies em hábitats de transição Mata Atlântica-Caatinga.

El estrés por anegamiento e inundación de las plantaciones se ha convertido en un factor abiótico limitante del crecimiento, el desarrollo y la productividad de los cultivos. Para estudiar el efecto del anegamiento sobre el tomate tipo chonto, híbrido larga vida Roble F1, se realizó un experimento en condiciones de invernadero de plástico, con y sin sombrío (una polisombra negra con 56,4% de reducción lumínica en un día soleado) de plantas anegadas. Se utilizaron materas plásticas de 1 L de capacidad, con turba rubia como sustrato en mezcla con suelo orgánico en proporción 1:1, las cuales fueron anegadas con una lámina de agua hasta 4 cm por encima del sustrato durante 4, 8 y 12 días. Las variables evaluadas incluyeron altura de planta, número de hojas y frutos, y biomasa seca de los órganos. El estudio mostró que los periodos de 4, 8 y 12 días de anegamiento redujeron significativamente la altura de la planta y el número de hojas, después de 12 y 16 días de iniciado el anegamiento, respectivamente, mientras el número de frutos en las plantas anegadas fue significativamente menor a los 40 dda cuando terminó la evaluación. La hipoxia radical en las plantas anegadas durante 8 y 12 días, redujo la producción de biomasa seca, especialmente en frutos y raíces, mientras la interacción 12-días-anegamiento y sombrío disminuyó la masa seca total de la planta. La planta de tomate, en general, parece estar adaptada al efecto de este tipo de sombrío. Con el aumento de la duración del anegamiento aparecieron síntomas como clorosis y caída de hojas basales, además de la epinastia y coloración roja foliar, así mismo la formación de raíces adventicias.

Waterlogging and flooding stress have become major abiotic stress factors for the growth, development and productivity of crops. To study the effect of waterlogging on the chonto tomato long-life Roble F1 hybrid, an experiment was conducted in a plastic greenhouse, with and without black shade netting (with the 56.4% light reduction on a sunny day). Plastic pots (1 L capacity) were used with blond peat mixed with organic soil at a 1:1 proportion, which were waterlogged up to 4 cm above the substrate for 4, 8 and 12 days. The assessed variables included plant height, number of leaves and fruits, and dry biomass of the organs. The study showed that 4, 8, and 12 days of waterlogging reduced the plant height and number of leaves after 12 and 16 days from waterlogging initiation, respectively; while the number of fruits was significantly lower at 40 dwi, when the evaluation period finished. The root hypoxia in the plants waterlogged for 8 and 12 days reduced plant dry biomass production, especially in the fruits and roots; while the 12-days-waterlogging x shading interaction impaired the total plant dry mass. In general, the tomato plant seems to be adapted to the effect of this type of shading. Increased periods of waterlogging were accompanied by symptoms such as chlorosis, abscission of basal leaves, leaf epinasty, reddish coloring, and formation of adventitious roots.

Restoration of vegetation in perturbed areas (e.g., abandoned pastures) with late-successional tree species may help to bypass decades of low diversity by accelerating succession. To elucidate how leaf dynamics is related to high growth rates and survival in early successional environments, we evaluated the hypothesis that plasticity in foliar demography is positively related to establishment of seven late-successional tree species growing in sunny sites (pasture and edge) and dark sites (secondary forest) at Los Tuxtlas, Veracruz, Mexico. We monitored leaves from 517 individuals from all species at all habitats during one year. Individuals growing in secondary forest and edge showed higher leaf survival and lower leaf production than those growing in pasture. Individuals with higher growth rates and survival in pasture showed high plasticity in their leaf survival and low plasticity in their leaf production (stability) while individuals in edge and secondary forest with high survivorship were those with high stability in their leaf production. Our results indicate that Nectandra ambigens, Licaria velutina and Pouteria rhynchocarpa may be planted in pastures because they show high growth rates and survival there, besides, they have different maximal height as adults and therefore they will provide structural diversity to the restored forest. Species with low plant survivorship in pastures as Calophyllum brasiliense, Pimenta dioica, Amphitecna tuxtlensis and Eugenia inirebensis should be planted in great numbers or until a canopy of pioneers develop.

Para acelerar la sucesión vegetal y restaurar la vegetación en áreas degradadas (e.g., pastizales abandonados) se ha sugerido utilizar especies sucesionales tardías. Para determinar cómo la dinámica foliar está relacionada con altas tasas de crecimiento y supervivencia en sitios sucesionales tempranos, evaluamos la hipótesis de que la plasticidad en la demografía foliar está positivamente correlacionada con el establecimiento de árboles de siete especies sucesionales tardías creciendo en ambientes soleados (pastizal y borde) y obscuros (bosque secundario) en Los Tuxtlas, Veracruz, México. Se monitorearon cohortes de hojas de 517 individuos de siete especies arbóreas creciendo en los tres hábitats durante un año. Los individuos que crecieron en bosque secundario y borde tuvieron mayor supervivencia foliar y menor producción de hojas que aquellos que crecieron en pastizal. Los individuos con mayor crecimiento y supervivencia en pastizal tuvieron una plasticidad alta en su supervivencia foliar y plasticidad baja en su producción de hojas (estabilidad), mientras que los individuos en el borde y el bosque con tasas altas de supervivencia fueron aquello que tuvieron estabilidad alta en su producción foliar. Nuestros resultados indican que Nectandra ambigens, Licaria velutina y Pouteria rhynchocarpa pueden ser sembradas en pastizales ya que muestran tasas altas de crecimiento y supervivencia en esos hábitats, además alcanzan diferentes estaturas a la edad adulta por lo que proveerían de diversidad estructural al bosque resultante. Especies con supervivencia baja en pastizales como Calophyllum brasiliense, Pimenta dioica, Amphitecna tuxtlensis y Eugenia inirebensis podrían sembrarse en grandes cantidades o hasta que un dosel de pioneras se haya formado.

A dinâmica fotossintética da espécie pioneira tropical Byrsonima sericea DC. foi estudada durante o processo de regeneração de uma mata nativa por avaliações ecofisiológicas (trocas gasosas, fluorescência da clorofila a e conteúdo de pigmentos fotossintéticos) e parâmetros anatômicos das plantas em ambientes ensolarados e sombreados. As avaliações ecofisiológicas foram feitas mensalmente por um ano e os dados foram agrupados em estação seca e chuvosa. Byrsonima sericea DC. apresentou plasticidade anatômica que a capacita a se estabelecer em ambientes com contrastantes condições luminosas. Nas condições ensolaradas, ela produz lâmina foliar mais espessa (cerca de 420 µm) e epiderme adaxial plana, enquanto em ambientes sombreados, as folhas apresentaram a epiderme convexa e lâmina mais delgada (cerca de 393 µm). Não foram encontradas diferenças significativas na composição de pigmentos em função do ambiente, no entanto, durante a estação seca, as plantas apresentaram concentrações significativamente maiores de pigmentos fotossintéticos. As plantas de ambientes ensolarados mostraram diminuição na razão Fv/ FO (na estação chuvosa) e NPQ (na estação seca), mas não foram observadas diferenças entre as plantas de sol ou sombra numa mesma estação do ano. Taxas fotossintéticas significativamente maiores foram encontradas na estação chuvosa para as plantas de sol quando comparadas com as plantas de sombra (9.9±0.8 e 7.4±0.3 µmol m-2s-1, respectivamente). Aumento significativo na transpiração foi observado em plantas de sombra durante a estação seca, mas sem afetar a eficiência no uso da água. Dados ecofisiológicos sugerem que, principalmente as plantas mais expostas ao sol sofreram limitações hídricas durante a estação seca e que, na estação chuvosa, estas plantas aumentaram sua taxa fotossintética. Isso possivelmente foi devido a maior força de dreno resultante do maior crescimento neste período. Os dados sugerem que alterações anatômicas, especialmente a epiderme adaxial convexa, estariam auxiliando na captação de luz nas plantas sombreadas durante ambas as estações, prevenindo alterações nos pigmentos, como o aumento de clorofila b geralmente observado em plantas de sombra, mas não detectado no presente estudo. Outra conseqüência da maior quantidade de luz capturada por estas plantas de sombra foi que, durante a estação seca sua taxa fotossintética não diferiu da das planas de ambientes ensolarados. No entanto, quando a água não foi um fator limitante, um melhor desempenho fotossintético foi observado nesta espécie pioneira, em ambientes abertos.

The photosynthetic dynamics of the tropical pioneer species, Byrsonima sericea DC., were studied during the regeneration process of a native forest by evaluating ecophysiological (gas exchange, chlorophyll a fluorescence and photosynthetic pigment contents) and anatomical parameters of plants in sunny and shady environments. Ecophysiological evaluations were carried out monthly for one year, encompassing both a dry and a rainy season. Byrsonima sericea DC. presents anatomical plasticity that enables it to establish in environments with contrasting light regimes. In sunny conditions, it produced a thicker leaf (about 420 mm) and flat adaxial epidermis, whilst in the shade, leaves had a thinner convex adaxial epidermis (about 395 mm). No differences were found in the compositions of the pigments in the different environments, however, during the dry season, the plants presented a significantly higher concentration of photosynthetic pigments. In the sun, plants showed decreases in Fv/F0 ratio (in the rainy season) and NPQ (in the dry season), but no difference was observed between plants that were in the sun or in the shade. A significantly higher net photosynthetic rate was found only in the rainy season in the plants in the sun, compared to shaded plants (9.9±0.8 and 7.4±0.3 µmol m-2s-1, respectively). Significant increase in transpiration was observed in plants in the shade during the dry season, but no alterations were observed in the water use efficiency. Ecophysiological data suggest that mainly plants overexposed to the sun underwent water limitations during the dry season and that, in the rainy season, these plants increased their net photosynthetic rate, possibly due to the greater drainage force resulting from increased growth during this period. Data suggest that anatomic alterations, namely the convex adaxial epidermis, could aid in the supply of light to shaded plants during both seasons, precluding changes in the pigments, such as the increase in chlorophyll b usually observed in shaded plants, but not detected in the present study. Another consequence of the greater quantity of light captured by these shade plants is that during the dry season their net photosynthetic rate was not different from that of plants in a sunny environment. However, when water was not a limiting factor, a better photosynthetic performance was observed in this pioneer specie in open spaces.

O objetivo deste trabalho foi determinar as mudanças fisiológicas que ocorrem em acariquara (Minquartia guianensis) durante o processo de aclimatação à alta irradiância, bem como a estratégia de aclimatação dessa espécie. Plantas mantidas em baixa irradiância foram transferidas para alta irradiância por 290 dias. Durante esse período, foi medida a relação entre fluorescência variável e máxima (Fv/Fm), em folhas desenvolvidas à sombra e, após a senescência prematura por foto-oxidação, em folhas aclimatadas ao sol. Ao final do experimento, foram determinadas as características fotossintéticas e anatômicas da folha. A exposição à alta irradiância causou, logo após a transferência, forte fotoinibição e foto-oxidação parcial da folhagem, mas não provocou a morte da planta. Folhas produzidas no ambiente ensolarado apresentaram valores de Fv/Fm similares aos do controle. A fotossíntese saturada por luz e a fotossíntese saturada por CO2 foram 90 e 50% maiores em plantas aclimatadas à alta irradiância. A velocidade máxima de carboxilação da rubisco e a taxa máxima de regeneração da ribulose bisfosfato seguiram a mesma tendência. Folhas produzidas ao sol apresentaram maior densidade estomática e maior espessura foliar. A produção de folhas novas é a principal estratégia de aclimatação da acariquara à alta irradiância.

The aim of this work was to determine the physiological changes that occur in manwood (Minquartia guianensis) during the acclimation process to high irradiance, and also to determine the acclimation strategy of this species. Plants kept in low light were transferred to high irradiance for 290 days. During this period the ratio between variable fluorescence and maximum fluorescence (Fv/Fm) was measured in leaves developed in the shade, and after premature senescence due to photooxidation, in sun-acclimated leaves. At the end of the experimental period the anatomic and photosynthetic characteristics of leaves were determined. Exposure to high irradiance caused, just after transferring, strong photoinhibition and partial photooxidation, but did not cause plant death. Leaves produced in sunny environment showed Fv/Fm similar to that of control plants. Light-saturated photosynthesis and CO2 saturated-photosynthesis were 90 and 50% higher in plants acclimated to high irradiance. The maximum carboxylation velocity of rubisco and the maximum rate of ribulose bisphosphate regeneration followed the same trend. Leaves produced under sunlight had higher stomatal density and increased leaf thickness. The production of new leaves is the main acclimation strategy to high irradiance in manwood.

O crescimento e o conteúdo de nutrientes nas folhas foram comparados em plantas jovens envasadas de Copaifera langsdorffii crescendo em área sob irradiância total e em área sombreada sem estresse hídrico. A assimilação de carbono e as relações hídricas foram avaliadas por meio da fotossíntese líquida, da eficiência fotoquímica potencial e do potencial hídrico foliar durante cursos diários no período seco e chuvoso nas duas áreas com irradiâncias contrastantes. Maiores valores de biomassa total, altura e área foliar ocorreram na área sob irradiância plena. As plantas jovens sobreviveram sob estresse hídrico em condições naturais na área sombreada provavelmente em função do rápido e intenso acúmulo de biomassa nas raízes logo no início do desenvolvimento. Não houve diferença significativa em relação à concentração de nutrientes entre as plantas crescendo sob diferentes regimes de iluminação. A fotossíntese líquida sob sombreamento aumentou ocasionalmente quando feixes de luz que atravessaram as copas atingiram diretamente as folhas de C. langsdorffii. Esses feixes de luz ocorreram com maior intensidade e mais freqüentemente no período seco, mas foram mais efetivos para a assimilação líquida no período chuvoso. A habilidade das plantas jovens persistirem em condições naturais sob os dois regimes contrastantes de irradiância até 1.230 dias após a semeadura pode explicar a vasta distribuição de C. langsdorffii nas diferentes fisionomias do Cerrado e em outras formações florestais.

Growth and leaf nutrient content were compared in young potted plants of Copaifera langsdorffii in sunny and shaded areas without water stress. Besides, carbon assimilation and leaf water relations were evaluated by net photosynthesis, potential photochemical efficiency and leaf water potential during daily courses in dry and rainy periods under natural conditions in both contrasting irradiances. Higher values of total biomass, height and leaf area occurred in sunny than in shaded area. On the other hand, all young plants survived in shade under natural water stress probably by reason of fast and intense biomass accumulation in favor of roots in early development. There was no significant difference about nutrient concentration in leaves between plants growing in sunny and shaded areas. Net photosynthesis in shade increased occasionally when bunches of direct light reached the leaves. Theses sunflecks took place more frequently and at high intensity in dry period but they were more effective for net photosynthesis in rainy period. The ability of young plants to persist under natural conditions in contrasting irradiance up to 1,230 days after sowing could explain the wide distribution of C. langsdorffii in Cerrado physiognomies and in different types of forest.

Rumohra adiantiformis é uma pteridófita amplamente distribuída em regiões tropicais, conhecida como samambaia-preta e utilizada em arranjos florais. Suas frondes possuem formas e tamanhos variados, de acordo com o ambiente onde ocorrem. Este trabalho teve como objetivo avaliar a variabilidade fenotípica dos indivíduos desta espécie com hábitos e ambientes de ocorrência distintos, utilizando características morfológicas como indicadores de plasticidade. Frondes, de três diferentes formações vegetacionais, foram coletadas para a medição dos parâmetros morfológicos. Os valores médios de comprimento total da fronde, área foliar, densidade estomática e espessuras do mesofilo foram significativamente diferentes entre os três ambientes. Os dados sugerem que R. adiantiformis apresentou variabilidade fenotípica para a maioria das características analisadas, sendo que os indivíduos de hábito terrícola de sol foram os que mais diferiram morfologicamente em função das condições ambientais mais estressantes como maior deficit hídrico e a maior intensidade luminosa que estas plantas estão expostas.

Rumohra adiantiformis is a widely distributed species of Pteridophyte, known as black-fern and often used for floral bouquets. The plants have different leaf shapes and sizes according to the environment they occur. This paper describes the phenotypic variability of individuals of R. adiantiformis with distinct habits and environments, using morphological traits as indicators of plasticity. Leaves collected in three different types of vegetation were measured. The main values of total leaf length, leaf area, stomatal density, and thickness of mesophyll were significantly different among the three environments. The data suggests that R. adiantiformis shows phenotypic variability for most of the traits analyzed, the individuals of sunny terrestrial habitats were the most morphologically distinct. This result is probably associated with more stressing conditions of this environment, such as water deficit and higher light intensity.