71 resultados para Copaifera langsdorffii


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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Os fatores ambientais podem causar estresse nas plantas acarretando alterações no metabolismo ou desenvolvimento, consequentemente modifica as condições ótimas que afetam o ciclo de vida e induz respostas em todos os níveis funcionais do organismo. A seca é um fator que tem grande influência nas plantas. Algumas espécies arbóreas desenvolveram mecanismos morfológicos, fisiológicos e bioquímicos para superar eventual suprimento inadequado de água. A espécie estudada, Copaifera langsdorffii Desf. está presente em formações vegetais de transição do cerrado stricto senso para a floresta semidecídua. Essa característica possibilita analisar respostas fisiológicas perante os efeitos sazonais da seca presente nestas formações florestais. O objetivo do trabalho foi comparar as respostas fisiológicas de Copaifera langsdorffii Desf. Em relação ao contraste hídrico característico de floresta estacional semidecídua. Para compreeender os efeitos desta sazonalidade avaliamos alguns parâmetros ecofisiológicos como Condutância Estomática (gs), Conteúdo Relativo de Água (Relative Water Content –RWC), Déficit Pressão de Vapor (DPV), potencial água foliar (Ψw) e fluorescência da clorofila. As avaliações foram feitas ao final da época úmida (FEU), final da época seca (FES) e início da época úmida (IEU) ao longo de 3 períodos do dia 5:00h (Predawn – PD), 12:00h (Midday – MD) e 17:00h (Afternoon – AF). Após as análises observamos queda de gs e aumento do DPV, valores constantes de RWC e Ψw foliar no FES. Mesmo em condições de déficit hídrico as plantas não apresentaram mecanismos de fotoinibição

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The aim of this study was to evaluate the allelopathic effect of soil samples collected under the canopies of three specimens of Copaifera langsdorffii the germination of Lactuca sativa and survey the natural seed bank according to seasonality. To test the allelopathic effect was carried experiments of pre and post-emergence with seeds of L. sativa and to quantify the stock of seeds, soil samples were collected from three specimens at three distances from the stem (1, 2 and 3 m) and at three depths (0-5, 5-10 and 10-15cm) in the region of savanna in the dry and wet seasons. The samples tested in bioassay of pre-emergence no significant influence on germinability, mean germination time and mean germination speed, but showed a difference in the synchronism of germination, these data were independent of sampling station. In test for post-emergence was observed statistical difference in the parameters evaluate (length of primary roots and hypocotyls) in both seasons. To quantify the natural seed bank were macroscopic analysis of each soil sample with the help of stereoscopic microscope. The analysis of the natural seed bank showed a larger number of seeds in the 0-5cm and in distance of 2m for both seasons. The results suggest the presence of allelochemical substances in soil samples collected under the canopy of Copaifera langsdorffii.

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The aim of this study is to investigate the genetic control of growth traits in the initial phases of development in fragmented populations of Copaifera langsdorffii Desf., using microsatellite markers. For the effect two populations of C. langsdorffii were used: a municipal park located in Sao Jose do Rio Preto (SJRP) and at Assis Ecological Station (AES), both in the state of sao Paulo, Brazil. The model to estimate the heritability coefficient is the method of regression of a measure of phenotypic similarity and an estimate of kinship between paired individuals. The coefficients of relatedness and heritability were estimated for three classes of distance (10, 20 and 30 m) within populations. Estimates of heritability were low (maximum 0.15) for all traits, ranging from positive values for regenerating individuals of the population SJRP and from negative to positive for the juvenile population AES. In evolutionary terms, these results indicate little chance of changing the population mean of the characters studied by natural selection; with strong random environmental effects changing this average. The results also suggest that the heritability for height to decrease between regenerating to juvenile stage and the natural selection in natural populations is stronger in the early stages of plant development.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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O objetivo deste trabalho foi avaliar morfometricamente a neoangiogênese de retalhos cutâneos subdérmicos em ratos tratados com óleo de copaíba (Copaifera langsdorffii) em pomada a 10%. O delineamento experimental foi inteiramente casualizado, composto por três recursos farmacológicos. Foram utilizadas dez repetições para cada recurso, e cada animal foi considerado uma unidade experimental. Trinta ratos Wistar foram submetidos à elevação do retalho cutâneo dorsal subdérmico e distribuídos em três grupos: grupo controle absoluto, no qual os animais não receberam nenhum tratamento; grupo controle, no qual os animais receberam tratamento tópico diário com pomada com apenas veículo (glicerina e vaselina); e grupo tratado, no qual os animais foram tratados diariamente com óleo de copaíba em pomada a 10%. Os ratos foram tratados e observados por oito dias após o ato operatório. No oitavo dia de pós-operatório, realizou-se a análise macroscópica do retalho e foram coletados fragmentos das porções cranial, média e caudal do retalho cutâneo para análise histopatológica. A análise morfométrica mostrou diferença significativa para o número de novos vasos sanguíneos nas partes média e caudal do retalho cutâneo no grupo tratado. O óleo de copaíba mostra-se eficiente no aumento da neoangiogênese em retalhos cutâneos subdérmicos de ratos.

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Legume pulvini have a clearly delimited endodermis, whose variable content has been associated with the velocity and type of leaf movement: pulvini in leaves with fast nastic movement contain starch grains; pulvini in leaves with slow nastic movements have calcium oxalate crystals as well as starch grains in the endodermis. However, the studies carried out to date have involved few legume species. This study therefore purported to examine the consistency of this hypothesis in other legumes. Thus, the structure and content of the pulvinus endodermal cells of nine legumes of the Brazilian cerrado, with different types and velocities of leaf movement, were investigated: slow nyctinastic and heliotropic movements (Bauhinia rufa, Copaifera langsdorffii, Senna rugosa - Caesalpinioideae; Andira humilis and Dalbergia miscolobium - Faboideae; Stryphnodendron polyphyllum - Mimosoideae), slow heliotropic movement (Zornia diphylla - Faboideae), and fast seismonastic and slow nyctinastic and heliotropic movements (Mimosa rixosa and Mimosa flexuosa - Mimosoideae). Samples were prepared following standard plant anatomy and ultrastructure techniques. The endodermis of all the species contains starch grains. In the species displaying only slow movements, calcium oxalate prismatic crystals were observed in addition to starch grains, except in Zornia diphylla. in conclusion, oxalate crystals occur only in endodermal cells of pulvini that display slow movements, while starch grains are always present in pulvinus endodermal cells of plants with any kind of movement.

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Previous studies on legume pulvini suggest that the vascular system plays an important role in the redistribution of ions and transmission of stimuli during leaf's movements. However, the number of anatomical and ultrastructural studies is limited to few species. The aim of this paper is to investigate the structure and cellular features of the pulvinus vascular system of nine legume species from Brazilian cerrado, looking for structural traits pointing to its participation in the leaf's movements. Samples were excised from the medial region of opened pulvinus of Bauhinia rufa, Copaifera langsdorffii, Senna rugosa (Caesalpinioideae), Andira humilis, Dalbergia miscolobium, Zornia dilphylla (Faboideae), Mimosa rixosa, Mimosa flexuosa and Stryphnodendron polyphyllum (Mimosoideae), and were prepared following light microscopy, transmission electron microscopy and histochemical standard techniques. The vascular system occupies a central position, comprises phloem and xylem and is delimited by a living sheath of septate fibers in all the species studied. This living cells sheath connects the cortex to the vascular tissues via numerous plasmodesmata. The absence of fibers and sclereids, the presence of phenolic idioblasts and the abundance and diversity of protein inclusions in the sieve tube members are remarkable features of the phloem. Pitted vessel elements, parenchyma cells with abundant cytoplasm and living fibriform elements characterize the xylem. The lack of lignified tissues and extensive symplastic continuity by plasmodesmata are remarkable features of the vascular system of pulvini of the all studied species. (c) 2007 Elsevier Ltd. All rights reserved.