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ABSTRACT: This study o evaluated growth, leaf gas exchange and arbuscular mycorrhizal fungi root colonization in three medicinal plant species under different irradiance intensities. Fridericia chica (Bonpl.) L.G.Lohmann, Mikania laevigata Sch.Bip. ex Baker and Varronia curassavica Jacq. were propagated by cutting and cultivated for 120 days in artificially shaded environments using black shade-type screens, obtaining four irradiance levels: 100%, 70%, 50% and 30%. The experimental design was completely randomized in a 3 x 4 factorial scheme (three plant species and four irradiation levels) with seven replicates. The three medicinal species showed higher liquid assimilation, mass growth and arbuscular mycorrhizal fungi root colonization rates when exposed to environments with 70% light availability. In relation to physiological responses, V. curassavica presented higher photosynthetic rate, stomatal conductance and transpiration when submitted to 70% irradiance, being able to be cultivated in more open environments with higher irradiation levels. Conversely F. chica and M. laevigata presented shade tolerance characteristics. At the initial growth phase, the results obtained can be used as indicators to recommend the ideal cultivation environment for these species in agroforestry systems.

ABSTRACT: Medicinal plants are generally commercialized dried. However, temperatures used in their drying processes may interfere with the content and chemical composition of their essential oils. The Lippia origanoides possesses thymol in the essential oil that is stored in glandular trichomes. Thymol is a major component of economic importance in the chemical and pharmaceutical industry. The objective of this study was to evaluate the effect of the drying temperatures of L. origanoides leaves regarding trichome integrity, content, and chemical composition of the essential oil. The experimental design was completely randomized with four treatments defined by oven drying temperatures (40, 50, 60, and 70ºC) and four replications. Essential oil was extracted by hydro distillation and the essential oil contents were determined (%). Chemical composition of the oil was analyzed by gas chromatography coupled to mass spectrometry. Scanning electron microscopy was carried out to determine trichome integrity. Drying the L. origanoides leaves in a forced ventilation oven at 40°C minimized the loss of extracted essential oil content (17.5g kg-1) and relative thymol percentage. Leaves dried at the temperatures of 60 and 70ºC exhibited a higher percentage of ruptured trichomes and reduced essential oil content to 13.7g kg-1 and 11.8g kg-1, respectively.

Espécies vegetais são capazes de ajustar suas características fisiológicas, anatômicas e ultraestruturais aos fatores ambientais, como, por exemplo, a disponibilidade de radiação luminosa incidente. O objetivo deste estudo foi avaliar a influência de diferentes níveis de radiação luminosa na anatomia e ultraestrutura foliar de Ocimum gratissimum L. (Lamiaceae). As plantas foram cultivadas por 93 dias em quatro níveis de radiação fotossinteticamente ativa (20, 11, 7 e 4mol m-2 d-1). O incremento da intensidade de luz proporcionou aumento no espessamento dos parênquimas paliçádico e esponjoso e do limbo foliar, entretanto, a espessura da epiderme não foi alterada. Em relação aos aspectos ultraestruturais, verificou-se aumento no tamanho dos cloroplastos e grãos de amido e um aumento do empilhamento dos tilacoides com a redução da intensidade de luz. As variações anatômicas e ultraestruturais verificadas confirmam a plasticidade fenotípica dessa espécie em função da intensidade de radiação luminosa.

Alpinia zerumbet is a medicinal plant from Asian origin used in folk medicine for the treatment of hypertension, which effect is attributed to terpinen-4-ol, the major component of the essential oil. The objective of this work was to identify the essential oil secretory structures in the leaf, flower, root and rhizome of this plant, and analyze the content and the chemical composition of the oil in the different organs of the plant. Sections were subjected to histochemical test with Nadi reagent for in situ localization of secretion. The essential oil extraction was performed by hydrodistillation in a Clevenger apparatus and the compounds were identified in CG-EM/FID. The histochemical test was positive for terpenoids, confirming the presence of essential oil stored in secretory structures named oils cells present in all analyzed organs. The higher essential oil content was found on the leaf (0.30%), while the petal and the rhizome presented content of 0.10% and 0.06%, respectively. It was not possible to determine essential oil content of the root due to the low amount of biomass produced. There were qualitative and quantitative differences in the chemical composition of the essential oil in the different plant organs, but the major constituent in all of them was the terpinen-4-ol, followed by 1,8 cineol in the leaf and by the α-terpineol in the flower and rhizome.

A prática da adubação orgânica, além de fornecer nutrientes para as plantas, proporciona a melhoria da estrutura física do solo, aumenta a retenção de água, diminui as perdas por erosão e favorece o controle biológico. O elixir paregórico (Ocimum selloi Benth.) é uma espécie medicinal nativa das regiões Sul e Sudeste do Brasil onde é utilizada popularmente como antidiarréico, antiespasmódico e antiinflamatório. Este trabalho teve como objetivo verificar o efeito de diferentes doses de dois adubos orgânicos no crescimento, no rendimento e na composição do óleo essencial de elixir paregórico. Os experimentos foram conduzidos em Lavras, MG, em estufa plástica com os seguintes tratamentos de adubação: ensaio A - esterco bovino: 1) sem adubação (controle); 2) solo + 3kg m-2 de esterco; 3) solo+ 6kg m-2 de esterco; 4) solo+ 9kg m-2 de esterco; 5) solo + 12kg m-2 de esterco; ensaio B - Esterco avícola: 1) sem adubação (controle); 2) solo + 1,5kg m-2 de esterco; 3) solo + 3kg m-2 de esterco; 4) solo + 4,5kg m-2 de esterco e 5) solo + 6kg m-2 de esterco. Foi verificada a influência das doses de adubação com esterco bovino e galinha sobre o crescimento da planta em altura e diâmetro do caule, acúmulo de biomassa seca, AF, AFE, RPF, teor de clorofilas, espessura do limbo foliar, rendimento e composição química do óleo essencial.The organic fertilization provides nutrients for the plants, improves the soil physical structure, increases the water retention, reduces the erosion losses and favors the biological control. Ocimum selloi is a native medicinal plant of south and southeast of Brazil where is used popularly as antidiarrhetic, antispasmodic and anti-inflammatory. This research aimed to verify the effect of different doses of two organic fertilizers souces in O. selloi growth, essential oil yield and chemical composition. The experiments were carried out in Lavras, MG, with pots in polyethylene greenhouse with two manuring treatments: Test A - Cattle manure: 1) Soil without manuring (control); 2) Soil + 3kg m-2 cattle manure; 3) Soil + 6kg m-2 cattle manure; 4) Soil + 9kg m-2 cattle manure; 5) Soil + 12kg m-2 cattle manure; Test B - Chicken manure: 1) Soil without manuring (control); 2) Soil + 1.5kg m-2 chicken manure; 3) Soil + 3 kg m-2 chicken manure; 4) Soil + 4.5kg m-2 chicken manure and 5) Soil + 6kg m-2 chicken manure. The influence of cattle and chicken manuring doses was verified on plant height, stem diameter, dry biomass weight, TLA, SLA, LWR, chlorophylls content, leaf thickness, essential oil yield and composition.

A propagação vegetativa de espécies medicinais vem despertando interesse das pesquisas agronômicas, uma vez que se constitui no ponto de partida e em ferramenta básica para qualquer cultivo em escala comercial. Este trabalho objetivou determinar o comprimento de estaca e o tipo de substrato mais adequados para a propagação vegetativa de atroveran. Em condições de casa de vegetação sob nebulização intermitente, foram testados dois comprimentos de estacas (10 e 20cm) e três substratos (areia lavada, casca de arroz carbonizada e substrato comercial Plantmax®), em delineamento experimental em blocos casualizados, com quatro repetições e cinco estacas por parcela. Aos trinta e cinco dias, foram avaliados a porcentagem de enraizamento, o comprimento da maior raiz (cm) e a biomassa seca das folhas e das raízes (mg). Os resultados indicaram que a propagação vegetativa de atroveran por meio de estaquia é viável, uma vez que o seu enraizamento médio ficou acima de 70%. As mudas de atroveran obtidas de estacas com 20cm apresentaram maior biomassa seca das folhas e das raízes, apesar de o comprimento da estaca não ter afetado a porcentagem de enraizamento e o comprimento da raiz. Os tipos de substrato não proporcionaram efeito sobre o desenvolvimento das estacas de atroveran. Recomenda-se a produção de mudas de atroveran com estacas de 20cm de comprimento, utilizando-se qualquer um dos três substratos testados.The vegetative propagation of medicinal species is in increasing agronomic interest because it is the starting point and a basic tool for any cultivation in commercial scale. The objective of this work was to determine the best shoot cutting length and the best substrate for vegetative propagation of Ocimum selloi. Cuttings were placed in greenhouse conditions under intermittent mist. Two cutting sizes (10 and 20cm) and three substrate types (washed sand, carbonized rice hulls and commercial substrate Plantmax®) were tested. The experiment was in blocks randomly distributed in four replications and five cuttings for parcel. After thirty five days the percentage of rooting, the length of the bigger root (cm) and the leaf and root dry weight (mg) were analysed. The results indicated that the vegetative propagation of Ocimum selloi by cuttings is viable, once its mean rooting was over 70%. It was not observed significative interaction within the adopted treatments. The cuttings with 20cm length presented larger leaf and root dry weight but the percentage of rooting and the length of the bigger root was not affected by the cutting lenght. The substrate types did not present effect on the development of the cuttings. The production of Ocimum selloi seedlings is recommended with 20cm length cuttings using any substrate tested.

Contamination of medicinal plants with heavy metals as Pb and Cd can affect the growth and the essential oil production of the plants and represent a risk to those who consume as medicine. This study aimed to evaluate the effects of absorption and localization of Pb and Cd on growth, ultrastructural aspects of leaves and essential oil yield and composition of Mentha arvensis, applied on the soil with increasing concentrations (8, 16, 32, 64 and 128mg kg-1). There was a differential absorption of Pb and Cd by M. arvensis mainly concentrated in the roots. Pb was found in small amounts in the leaves while Cd largely exceeded the safety limit without symptoms of toxicity. The ultrastructural analysis revealed the metal accumulation on vesicles surrounding the mitochondria and the presence of electron dense deposits surrounding the mitochondria, nucleus and chloroplasts. Little changes caused by Pb and Cd application were not enough to affect the growth and essential oil yield and composition of M. arvensis