Abstract Background: The leaves have been used to define sections in the genus Brickellia, allowing us to postulate their taxonomic value in monophyletic groups, as well as to identify the degree of morphological similarity between species and sections in a taxonomic and phylogenetic context. Questions: The species of Brickellia section Barroetea can be differentiated by their leaf blade shapes?, do section Barroetea have leaf blades different from other sections of the genus?, do these leaf shapes represent a conserved trait in the genus? Studied species: Six species from the section Barroetea and 19 species from other sections of Brickellia and related genera (Ageratina and Carminatia) were analyzed. Methods: A linear discriminant analysis and a phylomorphospace analysis were performed to evaluate the conservation status of the leaf shape and to know their morphological differences. Results: Species of the section Barroetea showed significant differences at the specific level, except in Brickellia sonorana. Furthermore, the evaluated species of sections Barroetea, Brickellia, Coleosanthus, Leptanthodium, and Xerobrickellia tend to have ovate-deltoid shapes, except Microphyllae with reniform shapes, in Phanerostylis ovate or elliptical, and Gemmipedium and Kuhnia with linear shapes. The phylomorphospace reveals an overlap in the analyzed sections, where the ancestral sections show a greater morphological change than the recently diversified. The conservation of the leaf shape is not confirmed statistically. Conclusions: Most species of Brickellia section Barroetea can be differentiated between theme, but not from the other sections of the genus Brickellia by the leaf’s shapes. The leaf shape of the genus is not conservated.

Resumen Antecedentes: Las hojas han sido utilizadas para definir secciones en el género Brickellia, lo que permite postular su valor taxonómico en grupos monofiléticos, así como identificar el grado de similitud morfológica entre especies y secciones en un contexto taxonómico y filogenético. Preguntas: ¿Las especies de Brickellia sección Barroetea se pueden diferenciar con las formas de las láminas foliares?, ¿La sección se reconoce de las demás secciones del género con base en la forma foliar? ¿Las formas foliares son un rasgo conservado en el género Brickellia? Especies de estudio: Se utilizaron seis especies de la sección Barroetea y 19 especies de otras secciones de Brickellia y géneros relacionados (Ageratina y Carminatia). Métodos: Se realizó un análisis linear discriminante y un filomorfoespacio para conocer las diferencias y evaluar la conservación de la forma foliar. Resultados: Las especies de la sección Barroetea presentaron diferencias significativas a nivel específico, excepto en Brickellia sonorana. Las especies evaluadas de las secciones Barroetea, Brickellia, Coleosanthus, Leptanthodium y Xerobrickellia tienden a formas ovado-deltoideas, excepto Microphyllae donde son reniformes, en Phanerostylis ovadas o elípticas y en Gemmipedium y Kuhnia lineares. El filomorfoespacio muestra un traslape entre las secciones analizadas; las secciones ancestrales muestran un cambio morfológico mayor que las secciones de reciente diversificación y la conservación de la forma foliar no se confirmó estadísticamente. Conclusiones: La mayoría de las especies de Brickellia sección Barroetea se pueden diferenciar entre ellas, pero no de las demás secciones del género Brickellia. Las formas foliares no se conservan en las secciones del género.

ABSTRACT ASTM Mar-M247 is one of the superalloys used to manufacture gas turbine blades in power stations. This paper studies the microstructure across welded joints of a turbine blade made of a high-strength material (Mar-M247 alloy) employing AWS ERNiCrMo-3 as a filler alloy. This process was carried out using gas tungsten arc welding (GTAW). The dendritic and interdendritic structures were observed in the fusion zone. The results also showed the presence of epitaxial growth at the interface between the weld metal and the base alloy without solidification cracks. Al and Co concentrations gradually decrease towards the weld metal zone during the solidification process, while Cr content increases towards the fusion zone. Vickers hardness revealed that the hardness in the heat-affected zone (HAZ) is higher than that of the base metal and the weld metal zone, the average in the HAZ is 340HV, while in the base metal and the fusion zone is 322HV, 284HV respectively. Coarse grains in the HAZ were found with an agglomeration of carbides at the grain boundaries due to the input heat of the welding process.

Abstract Introduction: The great diversity of tropical timber species demands the development of new technologies capable of identifying them based on their patterns or anatomical characteristics. The application of convolutional neural networks (CNN) for the recognition of tropical timber species has increased in recent years due to the promising results of CNNs. Objective: To evaluate the quality of macroscopic images with three cutting tools to improve the visualization and distinction of anatomical features in the CNN model training. Methods: Samples were collected from 2020 to 2021 in areas of logging and sawmills in the Central Jungle, Peru. They were later sized and, after botanical and anatomical identification, cut in cross sections. A database of macroscopic images of the cross-section of wood was generated through cutting with three different tools and observing its performance in the laboratory, field, and checkpoint. Results: Using three cutting tools, we obtained high quality images of the cross section of wood; 3 750 macroscopic images were obtained with a portable microscope and correspond to 25 timber species. We found the ''Tramontina'' knife to be durable, however, it loses its edge easily and requires a sharpening tool, the ''Pretul'' retractable cutter is suitable for cutting soft and hard wood in small laboratory samples and finally the ''Ubermann'' knife is suitable for use in the field, laboratory, and checkpoint, because it has a durable sheath and interchangeable blades in case of dullness. Conclusion: The quality of the images is decisive in the classification of timber species, because it allows a better visualization and distinction of the anatomical characteristics in training with the EfficientNet B0 and Custom Vision convolutional neural network models, which was evidenced in the precision metrics.

Resumen Introducción: La gran diversidad de especies maderables tropicales demanda el desarrollo de nuevas tecnologías de identificación con base en sus patrones o características anatómicas. La aplicación de redes neuronales convolucionales (CNN) para el reconocimiento de especies maderables tropicales se ha incrementado en los últimos años por sus resultados prometedores. Objetivo: Evaluamos la calidad de las imágenes macroscópicas con tres herramientas de corte para mejorar la visualización y distinción de las características anatómicas en el entrenamiento del modelo CNN. Métodos: Recolectamos las muestras entre el 2020 y 2021 en áreas de explotación forestal y aserraderos de Selva Central, Perú. Luego, las dimensionamos y, previo a la identificación botánica y anatómica, las cortamos en secciones transversales. Generamos una base de datos de imágenes macroscópicas de la sección transversal de la madera, a través del corte, con tres herramientas para ver su rendimiento en el laboratorio, campo y puesto de control. Resultados: Usamos tres herramientas de corte para obtener una alta calidad de imágenes transversales de la madera; obtuvimos 3 750 imágenes macroscópicas con un microscopio portátil que corresponden a 25 especies maderables. El cuchillo ''Tramontina'' es duradero, pero pierde el filo con facilidad y se necesita una herramienta para afilar, el cúter retráctil ''Pretul'' es adecuado para madera suave y dura en muestras pequeñas de laboratorio; el cuchillo ''Ubermann'' es apropiado para el campo, laboratorio y puesto de control, porque tiene una envoltura duradera y láminas intercambiables en caso de pérdida de filo. Conclusiones: La calidad de las imágenes es decisiva en la clasificación de especies maderables, porque permite una mejor visualización y distinción de las características anatómicas en el entrenamiento con los modelos de red neuronal convolucional EfficientNet B0 y Custom Vision, lo cual se evidenció en las métricas de precisión.

Resumo Os equipamentos de proteção individual (EPIs) devem ser adotados por todos os grupos profissionais expostos a riscos de contato com material biológico. O objetivo é analisar fatores associados à não utilização de EPIs por trabalhadores acometidos por acidentes ocupacionais com material biológico. Estudo quantitativo, transversal, em que foram analisadas fichas de notificação de acidentes de trabalho com material biológico de municípios do Sul do Brasil de 2014 a 2019. Realizou-se análise não ajustada e ajustada dos dados e, após, utilizou-se a análise hierarquizada, sendo estabelecidas associações entre variáveis independentes e o desfecho. A frequência de não uso de EPI entre os anos foi de 76,5%. Ao final da análise hierarquizada, os fatores associados à não utilização de EPI foram: anos de ocorrência do acidente, situação de trabalho formal, reencape de materiais, punção venosa/arterial, administração de medicação, descarte inadequado de materiais, utilização de materiais como lâminas e lancetas e exposição da pele íntegra e não íntegra. Os fatores analisados apresentaram significativa associação com o não uso de EPIs e acidentes de trabalho com material biológico e ressaltam a importância de estratégias de intervenções baseadas na realidade vivenciada por cada ambiente laboral.

Abstract Personal protective equipment (PPE) should be adopted by all professional groups exposed to risks of contact with biological material. The aim is to analyze factors associated with the non-use of PPE by workers affected by occupational accidents with biological material. A quantitative, cross-sectional study was conducted to analyze notification forms of occupational accidents with biological material in municipalities in southern Brazil, from 2014 to 2019. Adjusted and unadjusted data analysis was performed and, subsequently, hierarchical analysis was used, and associations between independent variables and the outcome were established. The frequency of non-use of PPE over the years was 76.5%. At the end of the hierarchical analysis, the factors associated with the non-use of PPE were: years of accident occurrence, formal work status, recapping of materials, venous/arterial puncture, medication administration, inadequate disposal of materials, use of materials such as blades and lancets, and exposure of intact and non-intact skin. The factors analyzed showed a significant association with the non-use of PPE and work accidents with biological material, and highlight the importance of intervention strategies based on the reality experienced in each work environment.

Abstract Personal protective equipment (PPE) should be adopted by all professional groups exposed to risks of contact with biological material. The aim is to analyze factors associated with the non-use of PPE by workers affected by occupational accidents with biological material. A quantitative, cross-sectional study was conducted to analyze notification forms of occupational accidents with biological material in municipalities in southern Brazil, from 2014 to 2019. Adjusted and unadjusted data analysis was performed and, subsequently, hierarchical analysis was used, and associations between independent variables and the outcome were established. The frequency of non-use of PPE over the years was 76.5%. At the end of the hierarchical analysis, the factors associated with the non-use of PPE were: years of accident occurrence, formal work status, recapping of materials, venous/arterial puncture, medication administration, inadequate disposal of materials, use of materials such as blades and lancets, and exposure of intact and non-intact skin. The factors analyzed showed a significant association with the non-use of PPE and work accidents with biological material, and highlight the importance of intervention strategies based on the reality experienced in each work environment.

Resumo Os equipamentos de proteção individual (EPIs) devem ser adotados por todos os grupos profissionais expostos a riscos de contato com material biológico. O objetivo é analisar fatores associados à não utilização de EPIs por trabalhadores acometidos por acidentes ocupacionais com material biológico. Estudo quantitativo, transversal, em que foram analisadas fichas de notificação de acidentes de trabalho com material biológico de municípios do Sul do Brasil de 2014 a 2019. Realizou-se análise não ajustada e ajustada dos dados e, após, utilizou-se a análise hierarquizada, sendo estabelecidas associações entre variáveis independentes e o desfecho. A frequência de não uso de EPI entre os anos foi de 76,5%. Ao final da análise hierarquizada, os fatores associados à não utilização de EPI foram: anos de ocorrência do acidente, situação de trabalho formal, reencape de materiais, punção venosa/arterial, administração de medicação, descarte inadequado de materiais, utilização de materiais como lâminas e lancetas e exposição da pele íntegra e não íntegra. Os fatores analisados apresentaram significativa associação com o não uso de EPIs e acidentes de trabalho com material biológico e ressaltam a importância de estratégias de intervenções baseadas na realidade vivenciada por cada ambiente laboral.

Madagascar is a centre of speciation for the genus Thilachium Lour., which includes several species of small trees and shrubs occurring in a wide range of habitats. A new species of Thilachium, T. latifolium Fici, from the Analanjirofo Region of northeastern Madagascar is here described and illustrated. It is characterised by 1-foliolate leaves, leaf blades widely ovate or elliptic with shortly acuminate or acute apices, flowers in terminal, dense subumbels or corymbs, short pedicels and ellipsoid, ribbed fruit. The new species is related to T. madagascariense Fici, a species recently described from eastern Madagascar, differing in the wider, coriaceous leaves with shorter, mucronulate tip, flowers in terminal, 7-16-flowered subumbels or corymbs, shorter pedicels and longer anthers. The distribution, autecology and affinities of the new species are discussed, its conservation status is assessed, and an updated key is provided for the species of the genus Thilachium known from Madagascar.

Abstract Usually, scraps of X22CrMoV12-1 alloy are obtained through machining of steam turbine blades and recycled through casting. However, this process is considered too costly. The viability of recycling X22CrMoV12-1 scraps with addition of vanadium carbide (VC) through powder metallurgy was analyzed in this study. Scraps of X22CrMoV12-1 alloy with VC were milled in a planetary ball mill during 10, 30 and 60 hours. The granulometry of the powder was determined through laser granulometry. The evolution in particles morphology and amorphization was conducted using scanning electron microscope (SEM) and x-ray diffraction (DRX) techniques. Stress-strain curves were obtained through compressive strength test. The results indicated that the best milling condition found was 60 hours. Also, the X22CrMoV12-1 alloy with VC addition produced by powder metallurgy showed good mechanical strength. Thus, this route was considered promising to reshape this material with smaller energy involved in the process.

AISI 6160 steel is used to manufacture cutting blades and springs due to its high tensile strength and good ductility. However, it has low mechanical strength and low wear resistance. In this work, a duplex treatment consisting of CCPD followed by PN was performed to improve the surface properties of the steel. In addition, XRD, optical microscopy, microhardness, and sphere-disk tribological analysis were used to verify the surface changes of the samples. The results showed a significant improvement in surface hardness and better wear resistance of AISI 6160 Steel submitted to Duplex treatment. The sample submitted to the CCPD treatment for 4 hours and, after nitriding at 500 °C for 2 hours, presented higher surface hardness and wear resistance than the sample only subjected to plasma deposition, characterizing the efficiency of the use of the duplex treatment adopted in the present work.

ABSTRACT The issue of reducing tillage resistance and lowering energy consumption has become increasingly relevant. Strip tillage has a positive impact on soil protection and energy consumption reduction. This study analysed the tillage resistance components of rotary blades and their relationship with operating parameters and developed a mathematical relationship between tillage resistance and energy consumption (power and fuel consumption). We summarised tillage resistance into three parts: air resistance, lateral rotational friction resistance (divided into horizontal and vertical resistance), and shear force. By theoretical analysis and coupled simulation tests 11 (DEM-CFD), we obtained an air resistance, lateral rotational friction, and shear force of 0.0883 N, 97.21 N, and 893.496 N, respectively, accounting for 0.01%, 9.81%, and 90.18% of tillage resistance. Meanwhile, we found that horizontal resistance decreased linearly with the increase of angular speed, which was the opposite of vertical resistance. Horizontal and vertical resistance increased linearly with the increase in contact area. Shear force increased significantly with angular speed. Fuel consumption in the field test and tillage resistance and power consumption in coupled simulation was formed to build a correspondence point, and a mathematical relationship between tillage resistance, torque, and power and fuel consumption was established.

Abstract This study aims to analyze the energy and environmental performance of the manufacture of two models of wind turbine blades for a 300 MW wind farm. Material flow analysis (MFA) was used to prepare the mass balance, while life cycle assessment (LCA), based on ISO-14044, was used to evaluate three impact categories, considering sensitivity analysis to evaluate the replacement of wind turbine blade materials. Results showed that the manufacturing of wind turbine blades causes a 10% loss of material impregnated with fiberglass and epoxy resin. Fiberglass was the input with the highest contribution to water consumption, energy consumption, and the carbon footprint. The sensitivity analysis showed that, for the offshore scenario of higher capacity factor and longer lifetime, the carbon footprint contribution per electricity to be produced was 0.214 kg CO2eq/GJ, while for the onshore scenario of lower capacity factor and shorter lifetime, it was 1.37 kg CO2eq/GJ. When using jute fiber grown without irrigation as a substitute input for fiberglass, the reduction was 38% (onshore) and 42% (offshore) in water consumption, 18% (onshore and offshore) in energy consumption, and 24% (onshore) and 25% (offshore) in carbon footprint. The onshore model had a larger impact in all the categories evaluated than the offshore model. Therefore, the use of unirrigated jute fiber allows gains in energy and environmental performance.

Resumo Este estudo tem como objetivo analisar o desempenho energético e ambiental da manufatura de dois modelos de pás de turbina eólica para compor um parque eólico de 300 MW. A Análise de Fluxo de Material (AFM) foi utilizada para elaborar o balanço de massa, enquanto a Avaliação do Ciclo de Vida (ACV) baseada na NBR ISO-14044 foi utilizada para avaliar três categorias de impacto, na qual a análise de sensibilidade foi considerada para avaliar a substituição de materiais da pá de turbina eólica. Os resultados indicaram que a manufatura das pás de turbina eólica gera uma perda de 10% de material impregnado com fibra de vidro e resina epóxi. A fibra de vidro foi o insumo que apresentou a maior contribuição em relação ao consumo de água, consumo de energia e pegada de carbono. A análise de sensibilidade evidenciou que, para o cenário offshore de maior fator de capacidade e maior vida útil, a contribuição da pegada de carbono por eletricidade a ser produzida foi 0,214 kg CO2eq/GJ, enquanto para o cenário de onshore de menor fator de capacidade e menor vida útil foi 1,37 kg CO2eq/GJ. Ao se utilizar a fibra vegetal de juta cultivada sem irrigação como um insumo substituto da fibra de vidro, a redução do consumo de água é de 38% (onshore) e 42% (offshore), do consumo de energia é de 18% (onshore e offshore) e da pegada de carbono é de 24% (onshore) e 25% (offshore). O modelo onshore apresentou um maior impacto que o offshore em todas as categorias avaliadas. Portanto, é possível obter ganhos no desempenho energético e ambiental empregando fibra vegetal de juta não irrigada.

ABSTRACT The aim of this study is to simplify the difficult excavation that is caused by the root-sand complex in the process of harvesting Cyperus esculentus in the desert of Xinjiang by performing mechanical tests and analysis of the interaction between the vibrating excavation shovel and the rotary blade on the root-sand complex. The rotary blade number, rotary blade speed and digging depth were used as the test parameters, and the Cyperus esculentus breakage rate, root-grass crushing rate, and soil carrying rate were used as the test indicators. The characteristics of the influence of various factors and their interaction on the crushing and separation of the root-sand complex were explored. A parameter combination optimization model is verified by experimental data. The test results showed that the optimal combination was as follows: the number of rotary blades was 20, the rotational speed of the rotary blade was 373 r/min, and the digging depth was 12 cm. At this time, the Cyperus esculentus breakage rate, root-grass crushing rate, and soil carrying rate were 2.62%, 63.68% and 55.40%, respectively. This study can support the development of a Cyperus esculentus harvester suitable for deserts in Xinjiang.

Abstract Pteris congesta an endemic and endangered species was investigated to identify morphological differences between its sterile and fertile leaves. Our findings have unveiled, leaf dimorphism in both morphology and growth patterns between fertile and sterile leaves. The sterile leaves petioles exhibited equivalent growth to the laminae, achieving complete leaf expansion within a month. In contrast, the petioles of fertile leaves elongated more than twice the size of the leaf blades that remain closed for the initial 30 days. Spore germination was carried out in both sterile and non-sterile soils, and juvenile sporophytes were cultivated to allow for morphological comparisons with those collected from the wild. One month after sowing the spores germinated in both soils resulting in a uniseriate germ filament Vittaria-type, and differentiated into laminar gametophytes, forming a Ceratopteris-type prothallus. The first leaf of the sporophyte emerged two months after sowing, and its development was completed one month later. Based on our studies, we propose that seedlings cultivated from spores germinated in soil can be used for the reintroduction of endangered fern species.

Resumo Pteris congesta, uma espécie endêmica e ameaçada de extinção, foi investigada para identificar diferenças morfológicas entre suas folhas estéreis e férteis. Revelamos que há dimorfismo foliar tanto morfológico como também nos padrões de crescimento entre as folhas férteis e estéreis. Os pecíolos das folhas estéreis crescem de forma equivalente às lâminas e alcançam a expansão foliar completa em um mês. Em contraste, as folhas férteis alongam mais que o dobro do tamanho das lâminas foliares e permanecem fechadas nos primeiros 30 dias. A germinação de esporos foi realizada em solos estéreis e não estéreis, e esporófitos juvenis foram cultivados para permitir comparações morfológicas com aqueles coletados na natureza. Um mês após a semeadura, os esporos germinaram em ambos os solos resultando em filamentos germinativos unisseriados do tipo Vittaria que se diferenciaram em gametófitos laminares, formando um prótalo do tipo Ceratopteris. A primeira folha do esporófito emergiu dois meses após a semeadura, e seu desenvolvimento foi concluído um mês depois. Com base em nossos estudos, propomos que mudas cultivadas a partir de esporos germinados no solo possam ser utilizadas para a reintrodução de espécies de samambaias ameaçadas de extinção.

ABSTRACT Basil (Ocimum gratissimum - Lamiaceae), is a sub-shrub plant species with great economic importance for several regions, and studies on its growth, physiology, and reproduction become needed. The aimed research was to obtain a regression equation to estimate leaf area of O. gratissimum. 250 basil leaves were collected and the linear dimensions (length and width) and real leaf area of each leaf were measured. From these data, the products between length and width, length and length were calculated. Equations were obtained using regression models: linear, linear without intercept, quadratic, cubic, power, and exponential. The best equation was selected based on determination coefficient, Pearson’s correlation coefficient, Willmott’s agreement index and CS index, Akaike information criterion, mean absolute error and root mean square error. All equations proposed using the product between length and width (LW) can be used to predict the leaf area of O. gratissimum. However, the equation LA=0.54*LW1.03 (power model) is the most recommended to estimate the leaf area of this species.

Abstract The objective of this work was to evaluate the effect of salinity on Na+ and K+ distribution and on proline content in Urochloa brizantha and Urochloa decumbens grass cultivars. Plants were grown in nutrient solution and subjected to salt stress for nine days. Shoot and root lengths and proline, total chlorophyll, K+, and Na+ contents were determined. Salt stress reduced the shoot length of cultivar Marandu but not of Xaraés and Basilisk. Total chlorophyll content was not affected by salinity in U. brizantha cultivars, but increased in cultivar Basilisk of U. decumbens. Salt-induced proline accumulation was observed in all cultivars, with a higher increase in Marandu. The K+ content in leaf blades increased in the Marandu and Basilisk cultivars under salinity conditions. 'Basilisk' showed Na+ exclusion in shoot tissues, whereas 'Marandu' and 'Piatã', followed by 'Xaraés', exhibited a higher Na+ in leaf blades. The pattern of ion distribution among cultivars was attributed mainly to differences in the ability to control the ion transport from root to shoot, since the rates of ion uptake were similarly affected by salinity. Tolerance to salt stress in grasses of the Urochloa genus is associated to Na+ exclusion and not to proline accumulation in shoot tissues.

Resumo O objetivo deste trabalho foi avaliar o efeito da salinidade na distribuição de K+ e Na+ e no conteúdo de prolina em cultivares dos capins de Urochloa brizantha e Urochloa decumbens. As plantas foram cultivadas em solução nutritiva e expostas a estresse salino durante nove dias. Foram determinados os comprimentos da parte aérea e das raízes e os conteúdos de prolina, clorofila total, K+ e Na+. O estresse salino reduziu o comprimento da par te aérea da cultivar Marandu, mas não de Xaraés e Basilisk. O conteúdo total de clorofila não foi afetado nas cultivares de U. brizantha, mas aumentou na cultivar Basilisk de U. decumbens. Observou-se acúmulo de prolina em todas as cultivares sob estresse salino, com maior aumento em Marandu. O conteúdo de K+ nos limbos foliares aumentou nas cultivares Marandu e na Basilisk, em condições de estresse. 'Basilisk' apresentou exclusão de Na+ nos tecidos aéreos, enquanto 'Marandu' e 'Piatã', seguidas por 'Xaraés', apresentaram maior acúmulo de Na+ nos limbos foliares. O padrão de distribuição de íons entre as cultivares foi atribuído, principalmente, a diferenças na habilidade para controlar seu transporte da raiz aos tecidos da parte aérea, já que as taxas de absorção foram similarmente afetadas pela salinidade. A tolerância à salinidade em gramíneas do gênero Urochloa está associada à exclusão de Na+ e não ao acúmulo de prolina na parte aérea da planta.

ABSTRACT The objectives of this work were to characterize the histo-anatomical pattern and degradability and to determine the secondary compounds of maniçoba in the different accessions and maturation stages (young, mature and senescent). For the research, three accessions were selected (AC002, AC004 and AC038) from the municipalities of Barra de Santa Rosa, Monteiro and Boa Vista, respectively, which showed distinct genetic characteristics, such as morphological and agronomic characteristics, chemical composition and hydrocyanic acid content. The leaf blades showed a cuticle that covers the entire epidermis, with papillose cells in the abaxial region and in a tabular shape in the adaxial region. The cells on the abaxial side are thinner than on the adaxial side. In the phytochemical screening of maniçoba leaves, the presence of steroids, tannins, flavonoids and saponins was observed. The leaves of maniçoba (Manihot ssp.) showed absence of alkaloids in all stages and accessions evaluated. All accessions evaluated showed positivity for the presence of steroids, with superiority in accession 04 in all stages, while for the other accessions it decreased with the maturation of the plant, especially in accession 02. The presence and concentration of secondary metabolites vary between accessions and maturation stages.

RESUMO Os objetivos com este trabalho foram caracterizar o padrão histo-anatômico e a degradabilidade e determinar os compostos secundários da maniçoba nos diferentes acessos e estádios de maturação (jovem, maduro e senescente). Para a pesquisa foram selecionados três acessos (AC002, AC004 e AC038) dos municípios de Barra de Santa Rosa, Monteiro e Boa Vista, respectivamente, que apresentaram características genéticas distintas, como características morfológicas e agronômicas, composição química e teor de ácido cianídrico. As lâminas foliares apresentaram cutícula que recobre toda a epiderme, com células papilosas na região abaxial e em formato tabular na região adaxial. As células na face abaxial são mais finas do que na face adaxial. Na triagem fitoquímica das folhas de maniçoba, observou-se a presença de esteroides, taninos, flavonoides e saponinas. As folhas de maniçoba (Manihot ssp.) apresentaram ausência de alcalóides em todos os estádios e acessos avaliados. Todos os acessos avaliados apresentaram positividade para presença de esteróides, com superioridade no acesso 04 em todos os estádios, enquanto para os demais acessos a presença diminuiu com a maturação da planta, principalmente no acesso 02. A presença e concentração de metabólitos secundários variam entre acessos e estádios de maturação.