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The objective of this work was to analyze the floristic variation and phytosociological structure of weeds as influenced by relief and time of year in eucalyptus plantations in Santana do Paraíso and Guanhães - MG. The total area sampled for each locality was approximately 10 ± 3 hectares, comprising three types of relief: lowland, slope, and upper area. In each type of relief, 10 plots of 1 m² were sampled, corresponding to 30 plots per locality, where they were randomly allocated in a zigzag. The taxonomic identification was performed in four assessments, corresponding to the months of November and March, comprising two ratings each season, always at the same points, and geo-referenced using the Global Positioning System (GPS). A total of 3,893 individuals, 18 families and 61 species, were identified in Santana do Paraiso and a total of 1,166 individuals, 13 families and 58 species, in Guanhães. In both localities, the most representative families in terms of wealth were: Poaceae, Asteraceae, and Fabaceae. Galinsoga parviflora was the most abundant species. The Vernonia polyantes was identified only in the lowlands, while Arrabida florida was identified in the slope and upper area. On the other hand, Emilia coccinea, Sida rhombifolia, S. paniculatum and Spermacoce latifolia were common to all three environments. Commelina benghalensis was present only in the month of March, while G. parviflora was present only in the month of November. It was concluded that the floristic and phytosociological variation of weeds in eucalyptus plantations is influenced by the type of relief and time of year, which should guide the management practices used in the culture. Objetivou-se analisar a variação florística e a estrutura fitossociológica de plantas daninhas em função do relevo e da época do ano em cultivos de eucalipto nos municípios de Santana do Paraíso e Guanhães-MG. A área total amostrada para cada localidade foi de aproximadamente 10 ± 3 hectares, compreendidos em três tipos de relevo: baixada, encosta e parte alta. Em cada tipo de relevo, foram amostradas 10 parcelas de 1 m², correspondendo a 30 parcelas por município, onde foram distribuídas aleatoriamente em zigue-zague. A identificação taxonômica foi efetuada em quatro avaliações, correspondentes aos meses de novembro dos anos de 2009 e 2010 e março de 2010 e 2011, sempre nos mesmos pontos, os quais foram georreferenciados por meio do Sistema de Posicionamento Global (GPS). Foi identificado, no município de Santana do Paraíso, um total de 3.893 indivíduos, distribuídos em 18 famílias e 61 espécies; já em Ganhães identificaram-se 1.166 indivíduos, sendo 13 famílias e 58 espécies. Em ambos os municípios, as famílias mais representativas, em termos de riqueza, foram Poaceae, Asteraceae e Fabaceae. Galinsoga parviflora foi a espécie mais abundante. Vernonia polyantes ocorreu apenas na baixada, e Arrabida florida, na encosta e parte alta. Já Emilia coccinea, Sida rhombifolia, S. paniculatum e Spermacoce latifolia foram comuns aos três ambientes. Commelina benghalensis esteve presente apenas no período correspondente a março, assim como G. parviflora no mês de novembro. Diante do estudo, conclui-se que a variação florística e fitossociológica de plantas daninhas em cultivos de eucalipto é influenciada pelo tipo de relevo e pela época do ano, o que deve nortear práticas de manejo na cultura.

Butia capitata, an endemic palm of the Brazilian savanna threatened by deforestation, demonstrates low germinability due to seed dormancy. The present study characterizes the structure of the zygotic embryo and describes germination and seedling development. Pyrenes were sown into sandy soil substrates to germinate, and their embryos were also cultivated in vitro in MS medium; structural evaluations were made during their development. Seedling growth through the endocarp germ pore culminates in the protrusion of the cotyledonary petiole, with the root and leaf sheaths subsequently being emitted laterally from its extremity. The embryos are composed of the cotyledon (whose proximal third has a haustorial function) and a diminutive embryo axis that is contained within the cotyledonary petiole. The protoderm, ground meristem, and procambium can be observed in their typical positions in the embryo axis and cotyledon. The development of the vegetative axis could be observed on the second day of in vitro cultivation, with elongation of the embryo axis and the beginning of the differentiation of the first eophyll. Elongation of the cotyledonary petiole and the differentiation of the parenchyma and tracheary elements were observed during the second to fifth day. Although the hypocotyl–radicle axis is less differentiated than the plumule, root protrusion occurs on the eighth day, and the leaf sheaths are only emitted between the twelfth and the sixteenth days; the haustorium atrophied during this stage. The embryonic structure of B. capitata does not impose limitations on seed germination as dormancy is of the non-profound physiological type, and the 50 % elongation of the cotyledonary petiole serves as a morphological indicator of germination.

The goal of this study was to determine the symptoms and microscopic damage caused by fluoride on Spondias dulcis, a fluoride-sensitive species. The plants were exposed to simulated fog with fluoride (0, 5, 10, 15 and 20 mg L-1) for 20 min daily during four consecutive days. Samples from leaflets without any apparent fluoride injury were collected to microscopic analysis. The percentage of necrosed leaf area was measured, and the level of pollutant in the dry matter from the basal and apical portions of the plant was determined. The necroses began 24 h after the first simulation mainly from the base of the leaflets. A higher level of necrosis was observed at the apical portion of the plants, a region of higher fluoride accumulation. The damage on the surface of the leaflets was characterized as plasmolysis, erosion of the epicuticular waxes and epidermal rupture. Structurally, the noticeable accumulation of granules and droplets green stained by toluidine blue in the spongy parenchima and the boundaries of ending veinlets was observed. The limb thickness reduction occurred due to plasmolysis in the mesophyll, showing an apparent correlation with the damage observed on the surface. The parameters observed in the laboratory are promising for field biomonitoring studies.O objetivo deste estudo foi determinar os sintomas e danos microscópicos causadas pelo flúor em Spondias dulcis, espécie sensível a essa substância. As plantas foram expostas a nevoeiros simulados com flúor (0, 5, 10, 15 e 20 mg L-1) por 20 minutos diários, durante quatro dias consecutivos. Amostras de folíolos sem qualquer lesão aparente ao flúor foram coletadas para análise microscópica. Mensurou-se a percentagem de área foliar necrosada e o teor do poluente na matéria seca das porções basal e apical da planta. As necroses surgiram 24 horas após a primeira simulação e tiveram início, principalmente, a partir da base dos folíolos. As necroses foram mais severas na porção apical das plantas, região com maior acúmulo de flúor. O dano na superfície dos folíolos foi caracterizado como plasmólise, erosão das ceras epicuticulares e ruptura da epiderme. Estruturalmente, observou-se considerável acúmulo de grânulos e gotas coradas de verde pelo azul de toluidina no parênquima lacunoso e nas proximidades das terminações xilemáticas. Houve redução da espessura do limbo devido a plasmólise no mesofilo, havendo aparente correlação com os danos observados na superfície. Os parâmetros observados em laboratório são promissores para estudos de biomonitoramento em campo.

A distinção de Butia capitata e de B. odorata é baseada em poucos caracteres morfológicos, o que motiva a busca por mais dados que corroborem a separação. Como dados da anatomia foliar são relevantes na circunscrição de taxa em Arecaceae, objetivou-se descrever a anatomia foliar de B. capitata e comparar com a de B. odorata. Amostras da porção mediana das pinas foram coletadas e processadas de acordo com técnicas usuais em Anatomia Vegetal. A epiderme é unisseriada e possui cutícula espessa e ceras epicuticulares em formato de filamentos em anzol. As células subsidiárias arqueiam-se sobre as células-guarda localizadas no nível da hipoderme. O mesofilo é isobilateral e compacto. Os feixes vasculares são colaterais com extensão de bainha esclerenquimática alcançando a hipoderme. Stegmatas possuem corpos silicosos esféricos e drusóides. A nervura mediana é adaxialmente projetada, apresentando espessa camada fibrosa que circunda os feixes vasculares, adjacente ao parênquima clorofiliano. Tecido de expansão estratificado ocorre na face abaxial, nos limites do mesofilo com a nervura mediana. Ráfides ocorrem apenas em B. capitata. Os feixes diminutos da nervura mediana circundam totalmente o anel fibroso somente em B. odorata. Além de diagnósticos, esses caracteres são úteis para corroborar a separação atualmente proposta. The distinction between Butia capitata and B. odorata is based only on a few morphological characteristics, therefore there is a need for additional studies for supporting the separation of the species. As lamina anatomy characteristics are relevant in circumscribing Arecaceae taxa, this work aimed to describe B. capitata lamina anatomy and compare it with B. odorata. Samples from the middle portion of the pinnae were collected and processed in accordance with standard plant anatomy techniques. The epidermis is uniseriate and composed of a thick cuticle and epicuticular waxes into like hooked filaments. The subsidiary cells that arch over the guard cells are located at the hypodermis. The mesophyll is isobilateral and compact. The vascular bundles are collateral with a sclerenchymatic sheath extension that reaches the hypodermis. The stegmata cells have spherical and druse-like silica bodies. The midrib faces the adaxial surface with a thick fibrous layer surrounding the vascular bundles adjacent to the chlorenchyma. The stratified expansion tissue is on the abaxial surface, within the boundary between the mesophyll and midrib. Raphides are only found in B. capitata. Small bundles of the midrib fully surround the fibrous cylinder only in B. odorata. These characteristics are diagnostic and useful for supporting the proposed separation.

Plants have the ability to undergo morphophysiological changes based on availability of light. The present study evaluated biomass accumulation, leaf morphoanatomy and physiology of Neonotonia wightii andPueraria phaseoloides grown in full sunlight, as well as in 30% and 50% shade. Two assays were performed, one for each species, using a randomized block design with 10 replicates. A higher accumulation of fresh mass in the shoot of the plants was observed for both species under cultivation in 50% shade, while no differences were detected between the full sunlight and 30% shade. N. wightii and P. phaseoloides showed increase in area and reduction in thickness leaf when cultivated in 50% shade. There were no changes in photosynthetic rate, stomatal conductance, water use efficiency and evapotranspiration of P. phaseoloidesplants because growth environment. However, the shade treatments caused alterations in physiological parameters of N. wightii. In both species, structural changes in the mesophyll occurred depending on the availability of light; however, the amount of leaf blade tissue remained unaltered. Despite the influence of light intensity variation on the morphophysiological plasticity ofN. wightiiand P. phaseoloides, no effects on biomass accumulation were observed in response to light. As plantas têm a capacidade de sofrer mudanças morfológicas com base na disponibilidade de luz. O presente estudo avaliou a acumulação de biomassa, morfoanatomia foliar e fisiologia de Neonotonia wightii ePueraria phaseoloides cultivadas a pleno sol, bem como a 30 e 50% de sombra. Dois ensaios foram realizados, um para cada espécie, usando um delineamento de blocos casualizados com 10 repetições. Observou-se maior acúmulo de massa fresca na parte aérea das plantas para ambas as espécies cultivadas em 50% de sombreamento, enquanto não foram detectadas diferenças entre pleno sol e 30% de sombreamento. N. wightii e P. phaseoloides mostraram aumento de área e redução da espessura foliar quando cultivadas a 50% de sombreamento. Não houve alterações na taxa fotossintética, condutância estomática, eficiência no uso da água e evapotranspiração nas plantas de P. phaseoloidesem função do ambiente de cultivo. No entanto, os tratamentos sombreados causaram alterações nos parâmetros fisiológicos de N. wightii. Em ambas as espécies, mudanças estruturais no mesofilo ocorreram dependendo da disponibilidade de luz; no entanto, a quantidade de tecido da lâmina foliar permaneceu inalterada. Apesar da influência da variação de intensidade luminosa sobre a plasticidade morfofisiológica de N. wightii eP. phaseoloides não foram observados efeitos na acumulação de biomassa em resposta à luz.

In order to correlate sintomatology with anatomical alterations caused by acid rain in leaves of tropical species, seedlings and saplings of Spondias dulcis Forst. F., Mimosa artemisiana Heringer and Paula and Gallesia integrifolia (Spreng.) Harms were exposed to simulated low-pH acid rain (pH 3.0). Control plants were submitted only to rain with distilled water (pH 6.0). The plants were exposed daily to the acid rain for 20 min for 10 consecutive days. Necrotic spots on the leaf blade occurred and most of the injuries onset on the epidermis in all species studied. S. dulcis displayed epicuticular wax erosion and rupture of epidermis. The abaxial surface of M. artemisiana was colonized by a mass of fungi hyphae and stomatal outer ledge rupture occurred. Some epidermal cells of G. integrifolia showed appearance similar to plasmolysis. The plants accumulated phenolic compounds in necrotic areas. Afterwards, leaves presented injuries in the mesophyll and collapsed completely. Cells surrounding the injured areas accumulated starch grains in S. dulcis. M. artemisiana showed more drastic symptom intensity in response to acidic rain. S. dulcis displayed visual symptoms similar to G. integrifolia, however, anatomical alterations were more severe.

Avaliou-se o potencial prognóstico de parâmetros microscópicos de folhas assintomáticas de . Clusia hilariana Schltdl. expostas à deposição particulada de ferro (2.14 mg cm2 dia-1), por 45 dias consecutivos. Amostras de folhas jovens e expandidas sem sintomas foram coletadas e submetidas a técnicas usuais em microscopia de luz e eletrônica de varredura. Foram mensurados a altura das células epidérmicas de ambas as faces da folha e a espessura da hipoderme, do parênquima clorofiliano e da lâmina foliar. Danos micromorfológicos ocorreram na superfície abaxial de folhas jovens e em ambas as faces de folhas expandidas. Erosão da cera epicuticular e ruptura cuticular foram frequentes na face adaxial, enquanto na face abaxial, de ambas as folhas, houve perda da sinuosidade da parede anticlinal das células epidérmicas, deformação e obstrução estomática. Alterações micromorfométricas foram observadas em todos os tecidos foliares, exceto na altura das células epidérmicas em razão, provavelmente, da espessa cutícula e flanges cuticulares proeminentes. A maior diferença na espessura da lâmina foliar foi verificada nas folhas jovens de plantas expostas à SPMFe, indicando maior sensibilidade ao ferro particulado em comparação com as folhas expandidas. As alterações micromorfológicas e micromorfométricas observadas na lâmina foliar de . Clusia hilariana Schltdl. demonstraram o potencial prognóstico dessas ferramentas na avaliação de impactos causados pela deposição de particulados, em especial na vegetação natural de restinga, onde a exposição é crescente diante da expansão de usinas mineradoras implantadas em sua vizinhança. This study aims to evaluate the prognostic value of microscopic parameters of asymptomatic leaves of Clusia hilariana Schltdl. subjected to particulate deposition of iron (2.14 mg cm-2 day-1) for 45 consecutive days. Samples of young and expanded leaves without symptoms were collected and subjected to light and scanning electron microscopy techniques. The height of the epidermal cells on both surfaces of the leaf and the thickness of the hypodermis, the chlorophyll parenchyma, and the leaf blade were measured. Micromorphological injury occurred in the abaxial surface of young leaves and on both surfaces of expanded leaves. Erosion of the epicuticular wax and cuticle rupture were frequent on the adaxial surface, while on the abaxial surface of both leaves there was a loss of sinuosity on the anticlinal wall of the epidermal cells, stomatal deformity and obstruction. Micromorphometric alterations were seen in all leaf tissues except in the height of epidermic cells, probably due to the thick cuticle and prominent cuticular flanges. The highest difference in thickness of the leaf blade was seen in young leaves of plants subjected to SPMFe, indicating greater sensibility to particulate iron in comparison to the expanded leaves. The micromorphological and micromorphometric alterations in the leaf blade of Clusia hilariana Schltdl. showed the prognostic potential of these tools on the evaluation of impacts caused by the deposition of particulate matter, especially in the 'Restinga' natural vegetation, where the exposure is increasing due to the presence of iron ore industry in their surroundings.

Fluoride is among the most phytotoxic atmo- spheric pollutants, commonly linked to the appearance of lesions in susceptible plants around emitting sources. In order to assess the effects of fluoride on leaves of Spondias dulcisParkinson (Anacardiaceae), plants were examined 78 km (non-polluted area) and 0.78 km (pol- luted area) from an aluminium smelter. The level of fluoride increased with the exposure time of the plants in the polluted area. On the third day of exposure in the polluted area, necroses with typical colouration were observed. Micromorphological damage began at the abaxial epidermis, mainly associated with the stomata. Starch grain accumulation was more pronounced in the midrib. The cell membranes and chloroplasts were greatly affected by the pollutant. We observed accumu- lation of phenolic compounds and electron-dense mate- rial at the boundaries of the ending veinlets. The micro- scopic events described precede the appearance of symptoms and are therefore of prognostic value in predicting injury by fluoride and will be useful as biomarkers. The high sensitivity of S. dulcis to fluoride and the specificity of the symptoms confirm, for the first time, in an experiment of active biomonitoring, the potential of this species as a bioindicator.

Avaliou-se, neste estudo, o potencial de três macrófitas - Azolla caroliniana, Salvinia minima e Lemna gibba - com vistas à seleção de plantas para remediação de ambientes contaminados por atrazine. Foram realizados experimentos em casa de vegetação durante seis dias, em vasos contendo solução nutritiva Hoagland (0,25 de força iônica), nas seguintes concentrações de atrazine: 0; 0,01; 0,1; 1,0; e 10,0 mg L-1. A redução da biomassa acumulada pelas macrófitas foi observada, bem como os efeitos de toxidez evidenciados pela sintomatologia desenvolvida nas plantas, os quais causaram sua morte. Clorose e necrose observadas nas plantas mostraram a alta sensibilidade das três espécies ao herbicida. As plantas demonstraram baixo potencial para remoção de atrazine, quando expostas ao herbicida em baixas doses. Entretanto, na concentração de 10,0 mg L-1 de atrazine, L. gibba e A. caroliniana mostraram potencial para remover o herbicida da solução (0,016 e 0,018 mg de atrazine por grama de massa fresca, respectivamente). Esse fato provavelmente resultou do processo de adsorção de atrazine pela matéria morta. A porcentagem de atrazine removida da solução pelas plantas diminuiu quando estas foram expostas a altas concentrações do poluente. Azolla caroliniana, S. minima e L. gibba não foram eficazes na remoção do herbicida na solução. A utilização dessas espécies para sanar ambientes aquáticos mostrou-se limitada. The potential of three macrophytes, Azolla caroliniana, Salvinia minima, and Lemna gibba was assessed in this study to select plants for use in environmental remediation contaminated with atrazine. Experiments were carried out in a greenhouse over six days in pots containing Hoagland 0.25 strength nutritive solution at the following atrazine concentrations: 0; 0.01; 0.1; 1.0; 10.0 mg L-1. Decrease in biomass accumulation was observed in the three macrophytes, as well as toxic effects evidenced by the symptomatology developed by the plants which caused their deaths. The chlorosis and necrosis allowed to observe in the plants the high sensitivity of the three species to the herbicide. Plants presented low potential for removal of atrazine in solution when exposed to low concentrations of the herbicide. However, at the 10.0 mg L-1 atrazine concentration, L. gibba and A. caroliniana showed potential to remove the herbicide from the solution (0.016 and 0.018 mg atrazine per fresh mass gram, respectively). This fact likely resulted from the processes of atrazine adsorption by the dead material. The percentage of atrazine removed from the solution by the plants decreased when the plants were exposed to high concentrations of the pollutant. Azolla caroliniana, S. minima, and L. gibba were not effective in removing the herbicide from solution. The use of these species to remedy aquatic environments was shown to be limited.

(Toxicidade e acúmulo de flúor em hortaliças nas adjacências de uma fábrica de alumínio). Com o objetivo de avaliar o potencial de acumulação de flúor e o percentual deste elemento removido pela lavagem, quatro espécies de hortaliças foram expostas em área poluída. Spondias dulcis foi utilizada como bioindicadora de reação e apresentou sintomas típicos em resposta ao poluente. Somente a salsa apresentou sintomas. Apesar de aparentemente sadias, as folhas das outras espécies utilizadas para estudos microscópicos, exceto da cebolinha, evidenciaram alterações na superfície, principalmente associa- dos aos estômatos. Houve redução na espessura do limbo, mais acentuada no manjericão e na cebolinha, havendo formação de tecido de cicatrização na couve e condensação do conteúdo das células epidérmicas na salsa. As folhas subuladas e eretas da cebolinha favoreceram o menor acúmulo do poluente; já na salsa, as folhas laminares, recortadas e paralelas ao solo contribuíram para a maior retenção. A lavagem das folhas removeu 34,1 e 73,9% do flúor na cebolinha e na salsa, respectivamente, indicando que a maior parte do poluente encontrava-se internamente na cebolinha e externamente na salsa. O cultivo destas hortaliças em áreas poluídas por flúor é inadequado, pois os teores do poluente estão acima do recomendado para o consumo, mesmo após a lavagem das folhas. (Toxicity and fl uoride accumulation in herbs grown in the vicinity of an aluminum plant). To assess fl uoride accumulation potential and the percentage of fl uoride removed by washing, four herb species were exposed to a polluted area. Spondias dulcis was used as a responsive bioindicator and showed typical fl uoride response symptoms. Symptoms were observed only in parsley. Although apparently healthy, the leaves of the remaining herbs, except for chives, showed surface damage associated mainly with stomata when observed under the microscope. A reduction in leaf thickness was also observed, most prominently in basil and chives. Scar tissue was observed in kale, and a retraction of the protoplast of the epidermal cells was observed in parsley. The subulate, erect leaves of chives accumulated less fl uoride; on the other hand, parsley leaves are laminar, lobed and parallel to the soil, which contributed to higher pollutant retention. Washing the leaves removed 34.1 and 73.9% of the fl uoride on chives and parsley, respectively, indicating that for chives, most of the pollutant was found inside the leaves, while for parsley, the pollutant was located on the outside. Growing these herbs in fl uoride- polluted areas is not recommended, since pollutant percentages are above levels recommended for consumption, even after washing the leaves.

Visando avaliar os efeitos do fluoreto sobre capim-braquiária, plantas de Brachiaria brizantha e B. decumbens foram submetidas a nevoeiros simulados com fluoreto (10 µg ml-1). Amostras foliares de porções aparentemente sadias foram coletadas 24 horas após a última exposição para análises microscópicas. Folhas, raízes e rizomas foram submetidos à quantificação do teor de fluoreto. As folhas apresentaram necroses pequenas e esparsas. Somente as folhas acumularam fluoreto, apresentando teores 4,4 e 5,2 vezes maiores que no tratamento controle, em B. brizantha e B. decumbens, respectivamente, não havendo diferença no potencial acumulador das duas espécies. As principais alterações micromorfológicas observadas foram lesões próximas aos tricomas, sugerindo que estes sejam as vias preferenciais de entrada do poluente nas plantas. Porções foliares, visualmente sadias, de ambas as espécies apresentaram danos microscópicos antes do surgimento de sintomas, havendo perda da turgidez das células buliformes em B. brizantha e de todos os tecidos em B. decumbens. Alterações micromorfométricas foram observadas somente em B. decumbens, indicando sua maior sensibilidade ao fluoreto, em comparação com B. brizantha. A realização de experimentos de longa duração será fundamental para elucidar o potencial bioacumulador de B. brizantha. To assess the effects of fluoride on signal grass, plants of Brachiaria brizantha and B. decumbens were submitted to simulated fluoride fog (10 µg ml-1). Leaf fragments from apparently healthy portions were colleted 24 hours after the last exposure and used for microscopic analysis. Roots, leaves and rhizomes were submitted to fluoride content quantification. The leaves presented small, sparse necroses. The accumulation of fluoride was observed on the leaves only. B. brizantha and B. decumbens presented, respectively, 4.4 and 5.2 times more fluoride than the control treatment. No difference was observed concerning the accumulation potential of both species. The main micromorphological alterations observed were injuries near the trichomes, therefore, suggesting that these are the preferential routes by which pollutants enter the plants. Visually healthy leaf portions of the two species showed microscopic damages before symptoms appeared, presenting turgidity loss in the bulliform cells of B. brizantha and in all tissues of B. decumbens. Micromorphometric alterations were observed only in B. decumbens, indicating higher sensibility to fluoride in comparison to B. brizantha. Further studies of long duration will be essential to determine the bioaccumulation potential of B. brizantha.

Foram avaliados os efeitos da deriva de formulações comerciais de glyphosate sobre a superfície foliar e o crescimento de clones de eucalipto. Mudas de seis clones foram submetidas a 129,6 g ha-1 de glyphosate das formulações comerciais Scout®, Roundup NA®, Roundup transorb® e Zapp QI®. Entre os clones não foram identificadas diferenças quanto à tolerância ao glyphosate. Plantas expostas à deriva simulada de Roundup transorb® e Zapp QI® apresentaram, respectivamente, a maior e menor porcentagem de intoxicação. Observou-se menor massa seca em plantas expostas ao glyphosate, independentemente da formulação, e menor altura naquelas expostas ao Scout® e ao Roundup transorb®. As características quantitativas da superfície foliar não foram afetadas pelo glyphosate. As alterações micromorfológicas ocorreram na ausência de danos visíveis e foram observadas em ambas as faces da epiderme, em todos os clones avaliados. Danos como erosão e aspecto amorfo das ceras epicuticulares e infestação por hifas fúngicas ocorreram, independentemente da formulação utilizada. A avaliação anatômica da superfície foliar foi relevante para descrição e interpretação dos danos causados pelo glyphosate. Os dados de crescimento e de intoxicação indicam o Zapp QI® como a formulação de menor risco para a cultura do eucalipto quanto aos efeitos indesejáveis da deriva. The effects of commercial glyphosate drift on the leaf surface and growth of eucalypt clones were evaluated. Seedlings of six clones were submitted to 129.6 g ha-1 sub-rate of commercial glyphosate formulations Scout®, Roundup NA®, Roundup transorb® and Zapp QI®. No differences in tolerance to glyphosate were observed among the clones. Plants exposed to simulated drift of Roundup transorb® and Zapp QI® presented the highest and lowest intoxication percentages, respectively. Plants exposed to glyphosate reduced dry biomass, regardless of the formulation, and also reduced height of the plants exposed to Scout® and Roundup transorb®. Leaf surface characteristics were not affected by glyphosate application. However, the micromorphological damages occurred prior to the appearance of visible symptoms, and were observed on both faces of the epidermis, in all clones tested. Damages such as erosion and amorphous aspect of epicuticular waxes and infestation of fungal hyphae occurred, independently of the formulation used. The anatomical evaluation of the leaf surface effectively described the damages caused by glyphosate. The growth and intoxication data indicate Zapp QI® formulation as presenting the lowest risk to eucalypt culture, in relation to the undesirable herbicide drift effects.

A sintomatologia é um dos principais critérios adotados para avaliar os danos causados por fatores bióticos e abióticos em plantas. Contudo, aspectos microscópicos são necessários na compreensão dos mecanismos de intoxicação e no diagnóstico precoce da injúria. Objetivou-se no presente estudo avaliar os efeitos da deriva simulada de quatro formulações comerciais de glyphosate (Scout®, Roundup NA®, Roundup transorb® e Zapp QI®) sobre a morfoanatomia foliar de seis clones de Eucalyptus grandis (UFV01, UFV02, UFV03, UFV04, UFV05 e UFV06). Após a aplicação do glyphosate na dose de 129,6 g ha-1, acompanhou-se diariamente o surgimento de sintomas, e aos 14 dias coletaram-se amostras de folhas aparentemente sadias para as análises microscópicas. Todos os clones apresentaram cloroses e necroses a partir do quarto dia de exposição, independentemente da formulação utilizada. O clone UFV04 não apresentou injúrias anatômicas. Nos demais clones, os herbicidas ocasionaram plasmólise, colapso celular, hipertrofia e formação de tecido de cicatrização, porém não foram diagnosticadas variações na espessura das folhas. Visualmente, o Roundup transorb® foi o herbicida que provocou maior intoxicação nas plantas. Anatomicamente, plantas expostas ao Roundup NA® apresentaram maior número de danos. O clone UFV06 foi o mais sensível à ação das formulações testadas, considerando-se tanto a análise visual quanto a anatômica. Os resultados confirmam o valor diagnóstico da análise visual e prognóstico da anatomia vegetal, sendo o estudo conjunto desses parâmetros fundamental para avaliar a sensibilidade entre os clones e o potencial fitotóxico de herbicidas. Symptomatology is one of the most important criteria used to determine the damages caused by biotic and abiotic factors in plants. However, microscopic aspects are needed to elucidate intoxication mechanisms and early injury diagnosis. This work aimed to evaluate the effects of four commercial glyphosate formulations under simulated spray drift (Scout®, Roundup NA®, Roundup transorb® and Zapp QI®) on the morphoanatomy of six Eucalyptus grandis clones (UFV01, UFV02, UFV03, UFV04, UFV05 and UFV06). Following glyphosate application (129.6 g ha-1), symptoms were monitored daily and, at 14 days, leaf samples from the regions without visible symptoms were collected for microscopic analysis. All clones presented chlorosis and necrosis at the fourth day of glyphosate exposure, regardless of the formulation used. The UFV04 clone did not show any anatomical damage. The other clones suffered plasmolysis, cellular collapse, hypertrophy and formation of cicatrisation tissue. However, changes in leaf blade thickness were not observed. Plants exposed to Roundup transorb® presented the greatest visible intoxication percentage. Anatomically, plants exposed to Roundup NA® showed a higher number of damages. Analysis considering both anatomic and visible damages showed that UFV06 clone was the most susceptible to the formulations tested. The results confirmed the diagnostic and prognostic value of visual and anatomical analysis, respectively, and showed that these parameters are essential to evaluate clone susceptibility and the the phytotoxic potential of herbicides.

Com os objetivos de avaliar o grau de suscetibilidade e caracterizar as injúrias na morfoanatomia de folhas de Magnolia ovata, mudas foram submetidas à chuva simulada com flúor (10 µg.ml-1 de F-) por 10 dias consecutivos. No tratamento controle, utilizou-se apenas água deionizada. Folhas foram coletadas para quantificação de flúor na matéria seca e fixadas para análises em microscopia de luz e eletrônica de varredura. As folhas apicais apresentaram pequena porcentagem de necroses intervenais e marginais em uma ou ambas as faces e maior acúmulo de flúor, em relação ao controle, quando comparadas com as folhas da porção basal. A análise micromorfológica das folhas aparentemente sadias indicou alterações nas paredes periclinais externas da epiderme e formação de concavidades, além de cristas estomáticas danificadas, erosão de ceras epicuticulares e presença de esporos e hifas de fungos. A caracterização estrutural das injúrias evidenciou retração de protoplasto das células epidérmicas, colapso das células do mesofilo e da epiderme e acúmulo de compostos fenólicos em células das regiões necrosadas. As alterações micromorfológicas das folhas ocorreram antes que sintomas fossem observados, o que comprova a importância da micromorfologia na diagnose precoce da injúria. As plantas de M. ovata apresentaram poucos sintomas visuais em resposta ao flúor, entretanto as alterações morfoanatômicas indicam que essa espécie possui potencial para ser utilizada como bioindicadora. This work aimed to evaluate the degree of susceptibility and characterize the injuries caused by fluoride in the morphoanatomy of Magnolia ovata. Seedlings were subjected to fluoride simulated rain (10 µg.ml-1 of F-) during 10 consecutive days. In the control treatment, only deionized water was used. Leaves were collected for quantification of fluoride in the dry weight and fixed for light and scanning electron microscopy analyses. The apical leaves presented a small percentage of interveinal and margin necrosis in one or both leaf surfaces and greater fluoride accumulation, in relation to the control, than the basal portion leaves. Micromorphological analyses indicated that the areas apparently healthy of epidermis presented alterations in the external periclinal walls and formation of concave shapes, beyond damaged stomatic ledge, erosion of epicuticular waxes and presence of spores and fungal hyphae. The structural characterization of the injuries showed retraction of the protoplast of the epidermal cells, collapse of the mesophyll and epidermal cells and accumulation of phenolic compounds in cells of the necrotic regions. The micromorphological variations occurred before leaf symptoms, confirming the importance of micromorphology in early diagnosis of the injury. Plants of M. ovata presented few visible symptoms in response to fluoride; however, morphoanatomic responses suggest that this species possesses potential features to be used as a bioindicator.

This work aimed to evaluate the effects of simulated drift of glyphosate on the morphoanatomy of three eucalypt clones and to correlate the intoxication symptoms on a microscopic scale with those observed in this visual analysis. The effects of glyphosate drift were proportional to the five doses tested, with Eucalyptus urophylla being more tolerant to the herbicide than E. grandis and urograndis hybrid. The symptoms of intoxication which were similar for the different clones at 7 and 15 days after application were characterized by leaf wilting, chlorosis and curling and, at the highest rates, by necrosis, leaf senescence and death. Anatomically glyphosate doses higher than 86.4 g.ha-1 caused cellular plasmolysis, hypertrophy and hyperplasia, formation of the cicatrization tissue and dead cells on the adaxial epidermis. The spongy parenchyma had a decrease, and the palisade parenchyma and leaf blade thickness had an increase. The increased thickness in leaf blade and palisade parenchyma may be related to the plant response to glyphosate action, as a form of recovering the photosynthetically active area reduced by necroses and leaf senescence caused by the herbicide. Este trabalho teve como objetivo avaliar os efeitos da deriva simulada de glyphosate na morfoanatomia de três clones de eucalipto e correlacionar os sintomas de intoxicação em escala microscópica com aqueles observados à vista desarmada. Os efeitos da deriva do glyphosate foram proporcionais às doses testadas, sendo Eucalyptus urophylla mais tolerante ao herbicida que E. grandis e o híbrido urograndis. Os sintomas de intoxicação foram semelhantes para os diferentes clones testados, tanto aos 7 quanto aos 15 dias após a aplicação, sendo caracterizados, morfologicamente, por murcha, clorose e enrolamento foliar e, no caso das maiores doses, por necrose, senescência foliar e morte das plantas de eucalipto. Anatomicamente, doses de glyphosate superiores a 86,4 g.ha-1 provocaram plasmólise, hipertrofia e hiperplasia celular, formação de tecido de cicatrização e morte das células da face adaxial da epiderme. Observou-se diminuição na espessura do parênquima lacunoso e aumento na espessura do parênquima paliçádico e da lâmina foliar. O aumento na espessura da folha e do parênquima paliçádico podem estar relacionados à resposta das plantas ao glyphosate, como forma de compensar a área fotossinteticamente reduzida pelas necroses e senescência causadas pelo herbicida.

This work aimed to evaluate the effects of simulated glyphosate drift on leaf growth and micromorphology of Eucalyptus spp. clones, using subdoses. A factorial scheme consisting of three clones, Eucalyptus urophylla , E. grandis and the hybrid E. urophylla × E. grandis ( E. urograndis ) and five sub-rates (0; 43.2; 86.4; 172.8 and 345.6 g e.a. ha −1 of glyphosate) were used in a randomized block design, with four repetitions. The herbicide was applied on the plants so as not to reach the superior third, 23 days after seedling planting. At 7 and 15 days after application (DAA), the leaves collected from the first basal branch of the plants were processed according to the conventional methodology used for micromorphological studies. The effects of glyphosate drift were proportional to the rates tested, with E. urophylla being more tolerant to the herbicide than E. grandis and E. urograndis. Glyphosate symptoms were the same for the different clones tested, being characterized by wilting, chlorosis and leaf curling, and, at higher rates, by necrosis, foliar senescence and death of the eucalypt plants. Plants submitted to 172.8 and 345.6 g ha −1 of glyphosate had severe injuries in the aerial part, affecting their development, resulting in reduced height, stem diameter and dry mass at 50 DAA. The micromorphological damages occurred prior to the appearance of visible symptoms, with erosion of the epicuticular waxes and fungal hypha infestation in plants exposed to glyphosate drift being observed in the three clones. No marked difference in leaf micromorphology was observed that could explain the differential tolerance among the three clones studied. The results show that further studies on wax and cuticle constitution of Eucalyptus spp. are needed for the elucidation of the mechanisms of differential tolerance of eucalypt species and clones to glyphosate.

Nectários são comuns dentre as Leguminosae, estando freqüentemente localizados nas folhas. Objetivou-se caracterizar anatomicamente o caule, a folha e o nectário extrafloral de Chamaecrista trichopoda, bem como investigar a natureza química do secretado do nectário dessa espécie. As amostras foram submetidas a testes histoquímicos e técnicas usuais em anatomia vegetal, sendo analisadas ao microscópio de luz e eletrônico de varredura. Os folíolos são anfiestomáticos e dorsiventrais, apresentando feixes vasculares colaterais com fibras associadas. Nas células da bainha do feixe é comum a ocorrência de monocristais. Tricomas tectores unisseriados e multicelulares ocorrem na lâmina foliar e no caule. O caule apresenta epiderme unisseriada, com três a quatro camadas de colênquima subepidérmico, seguido internamente por duas a três camadas de colênquima. Na camada mais interna do córtex destacam-se idioblastos cristalíferos contendo monocristais, o feixe vascular é delimitado por fibras e a medula é parenquimática. As características anatômicas foliares e caulinares corroboram os dados existentes para a subfamília Caesalpinioideae. O nectário situa-se na parte adaxial do pecíolo e apresenta coloração alaranjada, com o ápice formando uma concavidade, bordas levemente abauladas e pedúnculo com cerca de 1 mm de altura. É comum a ocorrência de pequenas aberturas na superfície do nectário e hifas fúngicas na fase pós-secretora. Anatomicamente, confirmou-se uma estrutura semelhante à de um nectário, o qual é vascularizado por floema e xilema; o parênquima nectarífero ocorre abaixo da epiderme que apresenta cutícula espessa. Caracteres anatômicos do nectário podem auxiliar na taxonomia do gênero. As análises histoquímicas evidenciaram o acúmulo de tanino nas células do parênquima nectarífero, que pode funcionar como uma proteção à herbivoria. Observou-se a presença de poros na superfície do nectário, que podem ser sítios preferenciais de eliminação do néctar. Entretanto, futuras análises ao microscópio eletrônico de transmissão serão fundamentais para elucidar o processo de eliminação do néctar. Nectaries are common among the Leguminosae, being frequently located in the leaves. The aim of this work was to anatomically characterize the stem, leaf and extrafloral nectary of Chamaecrista trichopoda, as well as to histochemically investigate the composition of the nectary secretion of this species. The samples were submitted to histochemical tests and usual plant anatomy techniques and analyzed through light microscope and scanning electron microscope. The leaflets are amphistomatic, dorsiventral, with collateral bundles and present associated fibers. It is common the occurrence of monocrystals in the bundle sheath cells. Uniseriate and multicellular tector trichomes occur in foliar lamina and stem. The stem presents uniseriate epidermis. Below the epidermis, three to four layers of collenchyma are observed, followed by two to three layers of chlorenchyma. In the most internal layers of the cortex, crystalliferous idioblasts containing monocrystals are observed, and the bundle sheath is delimited by fibers and the pith is parenchymatic. The leaf and stem anatomy characteristics corroborate with the existing Caesalpinioideae subfamily data. The nectary is pedunculate, around 1mm high and located in the adaxial part of the petiole, presenting an orange-like color, with the apex forming a concavity and the borders slightly rounded. It is common the occurrence of small openings on the surface of the nectary and fungi hyphae in the post-secretory phase. Anatomically, a nectary structure was confirmed. The nectary is vascularized by phloem and xylem with the nectariferous parenchyma occurring below the epidermis, which presents a thick cuticle. Anatomic characters may help study genus taxonomy. Histochemical analyses evidence the accumulation of tannins in the cells of the nectariferous parenchyma, likely functioning as a protection against herbivore. It was observed on the nectary surface the presence of pores, which may be preferential sites of nectar elimination. However, further analyses using transmission electronic microscope are fundamental to elucidate the process of nectar elimination.

Spondias dulcis Forst. F. vem recebendo atenção especial por secretar uma goma que possui ação medicinal. Em outras espécies de Anacardiaceae, a maioria dos estudos sobre as estruturas secretoras refere-se à ultra-estrutura e desenvolvimento dos ductos, existindo poucas informações quanto à natureza química do secretado. O objetivo do presente trabalho foi caracterizar estrutural e histoquimicamente o sistema secretor do caule de S. dulcis. Amostras do caule jovem de plantas com 45 dias de idade foram submetidas às técnicas usuais em anatomia vegetal e a testes histoquímicos. O sistema secretor de S. dulcis apresenta ductos e idioblastos. Os ductos, muito longos, encontram-se associados ao floema e na medula, enquanto os idioblastos ocorrem no córtex e, também, associados ao floema. Os ductos apresentam um epitélio secretor unisseriado, formado por células cuneiformes a tabulares, de paredes delgadas, citoplasma denso e núcleo volumoso com nucléolo proeminente. Nos ductos associados ao floema, observam-se, externamente ao epitélio, duas a três camadas de células parenquimáticas, achatadas e dispostas radialmente, formando uma bainha. Os testes histoquímicos evidenciaram a presença de taninos nos idioblastos corticais. A secreção dos ductos é constituída, em sua maioria, por óleos essenciais, polissacarídeos e compostos fenólicos (provavelmente agliconas flavonóicas), o que permite caracterizá-la como uma gomorresina. Special attention is given to Spondias dulcis Forst. F. for its ability to secrete a gum with medicinal properties. In other species of Anacardiaceae, most of the studies report the ultrastructure and development of the ducts, being scarce data about the chemical composition of secretory products. The aim of this work is to study the anatomy of the secretory system of S. dulcis and characterize by histochemistry the secretion produced. Stems of plants with 45 days old were study by conventional plant anatomy methods. The main classes of secretion chemical compounds were characterized in situ by histochemical tests. The secretory system of S. dulcis consists in very elongate ducts and idioblasts. The ducts are associated to the phloem and in the pith, and the idioblasts occur near the phloem and in the cortex. Ducts are formed by a secretory epithelium of cuneiform to flattened cells, with thin walls, dense cytoplasm and large nuclei with prominent nucleoli. The ducts associated with phloem have, in addition to epithelium, two to three layers of flattened parenchyma cells arranged in a circle forming a sheath. The histochemical tests reveal the presence of tannins in the cortical idioblasts. The secretion of the ducts is mainly constituted by essential oils, polysaccharides and phenolic compounds (probably flavonoid aglycones), which led us to say that is a gum-resin.