Evaluation of antimicrobial activity of extracts of medicinal plants on three tomato phytopathogens

Antimicrobial activity of 45 extracts of medicinal plants were tested on Xanthomonas campestris pv. vesicatoria, Ralstonia solanacearum and Clavibacter michiganense subsp. michiganense. Some assays were done to verify the capability of these plants extrats to show an antibiosis. Five extracts (EAFQ, SM1, SM12, SM16, SA1) shown positive activity. The extract EAFQ expressed bactericide activity on C. michiganense. It suggests the possibility of using these actives substances in natura or as a model to synthesize industrialized products, intendind field utilization.

An integrated approach to identification and conservation of medicinal plants in the tropical forest - A Brazilian experience

An integrated and interdisciplinary research programme with native medicinal plants from tropical forests has been performed in order to obtain new forest products for sustainable use in regional markets vis-à-vis ecosystem conservation. For the success of this programme ethnopharmacological studies are very important with respect to (i) identification of useful plants including medicinal and aromatic species; (ii) recuperation and preservation of traditional knowledge about native plants; and (iii) identification of potential plants with economic value. The plants are selected with a view to evaluate efficacy and safety (pharmacological and toxicological studies), and phytochemical profile and quality control (phytochemical and chromatographic characterization). These studies are very important to add value to plant products and also to mitigate unscrupulous exploitation of medicinal plants by local communities, since multiple use of plants represents an excellent strategy for sustaining the tropical ecosystem through ex situ and in situ conservation. Thus, conservation of tropical resources is possible in conjunction with improvements in the quality of life of the traditional communities and production of new products with therapeutic, cosmetic and 'cosmeceutic' value. © NIAB 2005.

Diversity of vascular plants growing on walls of a Brazilian city

City walls are very specialized environments, conditioned by human activities. There is little information about plants that invade human-made habitats, and no study done in Brazil with plants growing up on walls. The aim of the present study was to survey the wall vascular flora of a Brazilian city, comparing the diversity found in its downtown and neighborhoods. Fieldwork was done in Jundiaí, São Paulo State, where data was collected in downtown and in five neighborhoods. In each place, three transects of 1 km were established and every plant individual was registered. Twenty-eight species were identified, all of them on the downtown transect and most also on the neighborhood transects. Five species were the most frequent, although none were dominant. The diversity indicies of the six transects were not significantly different, with an overall diversity of H′ = 2.93. © Springer Science + Business Media, Inc. 2006.

Photosynthetic responses and proline content of mature and young leaves of sunflower plants under water deficit

In mature and young leaves of sunflower (Helianthus annuus L. cv. Catissol-01) plants grown in the greenhouse, photosynthetic rate, stomatal conductance, and transpiration rate declined during water stress independently of leaf age and recovered after 24-h rehydration. The intercellular CO 2 concentration, chlorophyll (Chl) content, and photochemical activity were not affected by water stress. However, non-photochemical quenching increased in mature stressed leaves. Rehydration recovered the levels of non-photochemical quenching and increased the F v/F m in young leaves. Drought did not alter the total Chl content. However, the accumulation of proline under drought was dependent on leaf age: higher content of proline was found in young leaves. After 24 h of rehydration the content of proline returned to the same contents as in control plants.

Root volume and dry matter of peanut plants as a function of soil bulk density and soil water stress

Soil compaction may be defined as the pressing of soil to make it denser. Soil compaction makes the soil denser, decreases permeability of gas and water exchange as well as alterations in thermal relations, and increases mechanical strength of the soil. Compacted soil can restrict normal root development. Simulations of the root restricting layers in a greenhouse are necessary to develop a mechanism to alleviate soil compaction problems in these soils. The selection of three distinct bulk densities based on the standard proctor test is also an important factor to determine which bulk density restricts the root layer. This experiment aimed to assess peanut (Arachis hypogea) root volume and root dry matter as a function of bulk density and water stress. Three levels of soil density (1.2, 1.4, and 1.6g cm-3), and two levels of the soil water content (70 and 90% of field capacity) were used. Treatments were arranged as completely randomized design, with four replications in a 3×2 factorial scheme. The result showed that peanut yield generally responded favorably to subsurface compaction in the presence of high mechanical impedance. This clearly indicates the ability of this root to penetrate the hardpan with less stress. Root volume was not affected by increase in soil bulk density and this mechanical impedance increased root volume when roots penetrated the barrier with less energy. Root growth below the compacted layer (hardpan), was impaired by the imposed barrier. This stress made it impossible for roots to grow well even in the presence of optimum soil water content. Generally soil water content of 70% field capacity (P<0.0001) enhanced greater root proliferation. Nonetheless, soil water content of 90% field capacity in some occasions proved better for root growth. Some of the discrepancies observed were that mechanical impedance is not a good indicator for measuring root growth restriction in greenhouse. Future research can be done using more levels of water to determine the lowest soil water level, which can inhibit plant growth.

From infant industry to technology exports: the Argentine experience in the international sale of industrial plants and engineering works

Includes bibliography

Identification of poisonous plants in the heart of public squares of ribeirão Preto SP

Toxic plants, many ornamentals, may be present in gardens, backyards, parks, vases, squares and vacant lots around the cities. Some of these plants are well known and exuberant, with strong color and decorative aspects, but when swallowed or handled, can cause severe intoxication specially in children. The main objective was to identify the poisonous plants found in public squares of Ribeirão Preto downtown, among five squares: XV de Novembro Square, Carlos Gomes Square, Bandeiras Square, Luís de Camões Square and Sete de Setembro Square. In this study, a literature review was performed in order to know the species that have been recorded as toxic plant. For the species in question, the common name and therapeutic indication were recorded. Over all evaluated squares toxic species were found. Sete de Setembro Square was the most frequent species in a total of seven toxical species. The most common species in the surveyed places were: Euphorbia pulcherrima, Buxus semprevirens and Dracaena fragrans, popularly known as Poinsettia, Boxwood and Cornstalk Dracaena, respectively. The importance of doing studies in urban squares is to improve care to ensure the afforestation process of the cities.

Effects of soil and foliar application of soluble silicon on mineral nutrition, gas exchange, and growth of potato plants

Silicon can alleviate biotic and abiotic stresses in several crops, and it has beneficial effects on plants under nonstressed conditions. However, there is still doubt about foliar-applied Si efficiency and Si effects on mineral nutrition, physiological processes, and growth of potato (Solanum tuberosum L.) plants under wellwatered conditions. The objective of this study was to evaluate the effect of soil and foliar application of soluble Si on Si accumulation, nutrients, and pigments concentration as well as gas exchange and growth of potato plants. The experiment was conducted under greenhouse conditions in pots containing 35 dm3 of a Typic Acrortox soil. The treatments consisted of a control (no Si application), soil application of soluble Si (50 mg dm-3 Si), and foliar application of soluble Si (three sprays of 1.425 mM Si water solution, prepared with a soluble concentrate stabilized silicic acid), with eight replications. Both soil and foliar application of Si resulted in higher Si accumulation in the whole plant. Foliar application of Si resulted in the greatest Si concentration in leaves, and soil application increased Si concentration in leaves, stems, and roots. Silicon application, regardless of the application method, increased leaf area, specific leaf area, and pigment concentration (chlorophyll a and carotenoids) as well as photosynthesis and transpiration rates of wellwatered potato plants. However, only soil application increased P concentration in leaves and dry weight of leaves and stems. © Crop Science Society of America.

Comparison of Brazilian plants used to treat gastritis on the oxidative burst of helicobacter pylori -stimulated neutrophil

Ten Brazilian medicinal plants used to treat gastritis and ulcers were carefully selected on the basis of ethnopharmacological importance and antiulcerogenic activity previously described. The antioxidant activity of the methanolic extracts was determined in analysis conditions that simulate a real biological activity on inhibition of the oxidative burst induced in neutrophils using Helicobacter pylori as activator, by a luminol-amplified chemiluminescence assay. The extracts, at low concentration (5 g/mL), exhibited a large variation in inhibitory effects of H. pylori-induced oxidative burst ranging from 48% inhibition to inactive, but all extracts, excluding Byrsonima intermedia, had inhibitory activity over 80% at the concentration of 100 g/mL. The total suppressive antioxidant capacity measured as the effective concentration, which represents the extract concentration producing 50% inhibition of the chemiluminescence induced by H. pylori, varies from 27.2 to 56.8 g/mL and was in the following order: Qualea parviflora > Qualea multiflora > Alchornea triplinervia > Qualea grandiflora > Anacardium humile > Davilla elliptica > Mouriri pusa > Byrsonima basiloba > Alchornea glandulosa > Byrsonima intermedia. The main groups of compounds in tested extracts are presented. Differences in the phytochemical profile, quantitatively and qualitatively, of these plants can explain and justify their protective effect on the gastric mucosa caused by the neutrophil-generated ROS that occurs when H. pylori displays its evasion mechanisms. © 2013 Cibele Bonacorsi et al.

Model of wetland development of the Amapá coast during the late Holocene

Os tipos de vegetação atual, sequências sedimentares, dados de pólen e datações por radiocarbono obtidas em três testemunhos de sedimento da planície costeira de Calçoene foram utilizados para estabelecer uma história paleoecológica durante o Holoceno superior das zonas úmidas costeiras do Amapá conforme as mudanças no regime de inundação, nível do mar e clima. Baseado nestes três registros, quatro fases de desenvolvimento da vegetação são apresentadas e provavelmente refletem a interação entre o fluxo de energia na acumulação do sedimento e a influência das águas salobras e doces na vegetação. Este trabalho sugere alternâncias entre períodos caracterizados por influências marinha e fluvial. O perfil longitudinal não revelou a ocorrência de manguezais nos sedimentos depositados por volta de 2100 anos A.P. Durante a segunda fase, a lama preencheu progressivamente as depressões e canais de maré. Provavelmente, os manguezais iniciaram seu desenvolvimento nas margens dos canais, e os campos herbáceos nos setores elevados. A terceira fase é caracterizada por uma interrupção no desenvolvimento dos manguezais e a expansão da vegetação de várzea devido a uma diminuição na influência das águas marinhas. A última fase é representada pela expansão de manguezais e várzeas. A correlação entre os padrões atuais de distribuição das unidades geobotânicas e a paleovegetação indica que os manguezais e as florestas de várzea estão migrando sobre os campos herbáceos nos setores topograficamente mais elevados do litoral em estudo, o que pode estar relacionado a um aumento do nível relativo do mar.

Copper oxychloride fungicide and its effect on growth and oxidative stress of potato plants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The Influence of Municipal Treated Wastewater on Morpho-Physiological Characteristics of Eucalyptus Plants

The effects of municipal-treated wastewater on growth and gas exchange characteristics were studied in eucalyptus plants cultivated in a greenhouse under continuous sub irrigation with 70 % Long Ashton solution as a control, 100 % treated wastewater, and treated wastewater diluted 50 % with tap water. Irrigation with wastewater resulted in a reduction of total dry matter per plant and the shoot-to-root ratio and increased specific leaf mass, irrespective of the dilution. The gas exchange characteristics were adversely affected by the irrigation with wastewater, with photosynthetic rates been negatively affected. Total chlorophyll and carotenoids content were reduced in plants grown under treated wastewater. The results demonstrated that when the eucalyptus plants were grown under treated wastewater as the only source of mineral nutrients they were able to produce nearly 50 % of the dry matter produced by the plants grown under appropriate mineral nutrient supply, irrespective of the dilution. Therefore, the contribution of mineral nutrients and organic matter from the treated wastewater used as agricultural irrigation will be significant in lower the fertilizer rates without reducing dry matter production per plant.

Contamination of wetland soils and floodplain sediments from agricultural activities in the Cerrado Biome (State of Minas Gerais, Brazil)

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