Interpretación ambiental de INBioparque, La Finca (Costa Rica)

Este artículo es una síntesis del proyecto realizado en INBio (Instituto Nacional de Biodiversidad), Costa Rica, cuyo objetivo principal fue la mejora de la Interpretación Ambiental de INBioparque, un parque temático de biodiversidad dentro de la institución. INBioparque está situado en Santo Domingo de Heredia, provincia de Heredia, Costa Rica. Éste pretende hacer una pequeña representación de los principales ecosistemas que se encuentran en el país. El parque se divide en diferentes zonas: Bosque del Valle Central, Bosque Húmedo, Bosque Seco, Humedal y Finca. En esta última, la Finca (ecosistema basado en la biodiversidad domesticada) es dónde se ha centrado todo el proyecto, debido a que presentaba una mayor necesidad de mejora en su interpretación ambiental. La Interpretación ambiental traduce el lenguaje técnico de los profesionales a términos e ideas más entendedoras para todos los públicos. Pretende promover una nueva conciencia sobre el valor de la biodiversidad, lograr su conservación y mejorar la calidad de vida del ser humano. El proyecto propone la mejora de la interpretación ambiental a través de las fichas técnicas elaboradas de las diferentes especies vegetales de la Finca, así como la renovación o creación de rótulos explicativos. Se propone también un recorrido guiado y auto guiado para hacer más entendedora la visita, además de algunas actividades y talleres.

Estudo fitoquímico e avaliação alelopática de Memora peregrina - "ciganinha" - Bignoniaceae, uma espécie invasora de pastagens em Mato Grosso do Sul

Memora peregrina (local name: 'ciganinha' - Bignoniaceae) is a weed that often invades pastures in the Brazilian state of Mato Grosso do Sul. From its leaves and subterranean parts, the following compounds were isolated: allantoin (20.7 w/w in subterranean parts), the iridoid 6beta-hydroxyipolamiide, hyperin, 3'-O-methylhyperin, 4-hydroxy-N-methylproline, beta-sitosterol, alpha-amirin and beta-amirin, and lupeol. Allantoin exhibited an activity of inducing germination in seeds of Lactuca sativa used as a biological model, and the iridoid showed moderate activity in the larval development of Anagasta kuehniella. These results, associated with this plant's behavior, are suggestive of the occurrence of adaptive and competitive strategies in relation to other plant species.

Isolation of compounds attractive to the leaf-cutting ant Atta sexdens rubropilosa forel (hymenoptera: Formicidae) from Mabea fistulifera elaiosome

Mabea fistulifera (Euphorbiaceae)is a pioneer plant species with seeds dispersed by the ant Atta sexdens rubropilosa. Since the ants are attracted to the seeds to use its elaiosome as a source of energy, we investigated its composition. The elaiosomes from 13,000 seeds were extracted with a methanol:chloroform mixture (2:1 v/v) and yielded 22% of a residue. This residue was fractionated by column chromatography and its composition determined by infrared spectroscopy and chromatography/mass spectrometry (GC-MS). The elaiosome lipids are constituted mainly by free fatty acids, triacylglycerols and minor quantities of monoacylglycerols or diacylglycerols.

Effects of landscape evolution on flora and habitats in agricultural mosaics

A landscape mosaic is a landscape that consist of various patches, inhabited by different habitat communities over time. Agricultural mosaics area result of the long history between societies and the environment. The understanding of the driving forces for change in this landscapes, and their effect on biodiversity, allow the development of useful tools to assess and manage natural heritage. Plant diversity, endangered plant species and interesting habitats receive the center of attention, because of their capability to integrate and reflect the main changes of this landscapes after medium and long-term.

Alucinógenos naturais: um voo da Europa Medieval ao Brasil

This work describes the historical importance and the use of hallucinogenic plants by different civilizations. A comparison between three Brazilian plants whose active principle is N,N-dimethyltriptamine (DMT), and three plant species native to Europe whose active principles are tropanic alkaloids was carried out and we observed these plants promoted different types of hallucinations.

Desenvolvimento de dispositivo caseiro para dessalinização de água salobra a partir de sementes de umbu (Spondias tuberosa Arruda Câmara)

The goal of this work was to develop a homemade device to desalinate brackish water, using biological material like seeds from different plant species of the semi arid regions. Umbu seeds (Spondias tuberosa Arruda Câmara) were found to be the most appropriate material, removing a higher quantity of salt from the water compared to the other tested materials. The salt content in 1 L of brackish water typical of the region can be removed with only 1 g of the material, if the water is heated to 50 °C and it may also lower the water hardness, achieving drinking water standards.

Chumbo e cádmio detectados em alimentos vegetais e gramíneas no município de Santo Amaro-Bahia

This study evaluated the level of the metals Pb mg kg-1 and Cd mg kg-1 found in plant species and the contribution of the levels detected in contaminated soils located in the urban area of the city of Santo Amaro, Bahia. Levels were determined by graphite furnace and flame atomic absorption spectrometry. The results showed the presence of Pb and Cd in plant species at levels ranging from 0.18 to 118.2 mg kg-1 and 0.04 to 7.29 mg kg-1, respectively. The concentration values obtained varied according to the plant species and were not strongly influenced by the concentration values detected in the soil.

Chemical constituents isolated from turnera subulata Sm. and electrochemical characterization of phaeophytin b

Turnera subulata Sm., known as "Chanana" or "flor-do-Guarujá" in Brazilian folklore, is a plant species belonging to the subfamily Turneroideae of family Passifloraceae, which is used for various medicinal purposes in Brazil. The phytochemical study conducted here led to the isolation and identification of ten compounds present in T. subulata: two mixtures of steroids, sitosterol and stigmasterol (nonglycosylated and glycosylated); a mixture of flavonoids, 5,7,4′-trihidroxiflavona-8-C-α-glucopyranoside and 5,7,3′,4′-tetrahidroxiflavona-8-C-α-glucopyranosidel; and four phaeophytins, phaeophytin purpurin-18-phytyl ester, a rare natural product, phaeophytin a , 13²-hydroxy-(13²-S)-phaeophytin a , and phaeophytin b Phaeophytin b exhibited electrochemical activity similar to that of phthalocyanines.

Silicon and rice disease management

The element silicon (Si) is not considered an essential nutrient for plant function. Nevertheless, Si is absorbed from soil in large amounts that are several fold higher than those of other essential macronutrients in certain plant species. Its beneficial effects have been reported in various situations, especially under biotic and abiotic stress conditions. The most significant effect of Si on plants, besides improving their fitness in nature and increasing agricultural productivity, is the restriction of parasitism. There has been a considerable amount of research showing the positive effect of Si in controlling diseases in important crops. Rice (Oryza sativa), in particular, is affected by the presence of Si, with diseases such as blast, brown spot and sheath blight becoming more severe on rice plants grown in Si-depleted soils. The hypothesis underlying the control of some diseases in both mono- and di-cots by Si has been confined to that of a mechanical barrier resulting from its polymerization in planta. However, some studies show that Si-mediated resistance against pathogens is associated with the accumulation of phenolics and phytoalexins as well as with the activation of some PR-genes. These findings strongly suggest that Si plays an active role in the resistance of some plants to diseases rather than forming a physical barrier that impedes penetration by fungal pathogens.

Annona squamosa, a new host of Ceratocystis fimbriata

Mango branch blight disease, caused by Ceratocystis fimbriata, is endemic to the municipality of São Fidelis in northern Rio de Janeiro State. In addition to mango, C. fimbriata was found associated with sugar apple trees (Annona squamosa) showing symptoms of branch blight in São Fidelis. Sugar apple and mango isolates from the same region had the same morphology and showed similar ITS-rDNA sequences. These sequences were also similar to other Brazilian isolates of C. fimbriata sensu stricto. Cross inoculation of such isolates obtained from diseased sugar apple and mango resulted in diseased symptoms on both plant species. This is the first record of A. squamosa as a host for C. fimbriata.

Hemiselluloosien erotus ja in situ -modifiointi

Hemiselluloosat kuuluvat selluloosan ja ligniinin ohella puun ja muiden kasvimateriaalien päärakenneaineksiin. Hemiselluloosan kemiallisessa koostumuksessa on eroja kasvilajien välillä, mikä tekee ryhmästä hyvin monimuotoisen. Lehtipuiden pääasiallinen hemiselluloosa on glukuroniksylaani. Ksylaaneja esiintyy laajasti myös muissa kasveissa erilaisina rakenteina. Havupuiden yleisin hemiselluloosa on puolestaan galaktoglukomannaani. Arabinogalaktaani on erityisesti lehtikuusesta runsaana löytyvä hemiselluloosa, jota muissa puulajeissa on vain vähän. Luonnon polymeerejä tutkitaan jatkuvasti muun muassa vaihtoehtojen löytämiseksi raakaöljypohjaisille tuotteille. Aiemmin hemiselluloosia on pääosin hyödynnetty sellaisenaan tai jalostettu esimerkiksi sokereiksi. Selluloosan ja tärkkelyksen tavoin ne voivat kuitenkin toimia myös kemiallisen, fysikaalisen tai entsymaattisen muokkauksen lähtöaineena. Hemiselluloosien käyttöä rajoittaa usein se, että niiden eristäminen kasvimateriaalista hyvällä saannolla on vaikeaa. Useimmiten hemiselluloosa erotetaan biomassasta ligniinin poiston jälkeen uuttamalla erilaisilla reagensseilla, kuten emäksillä. Arabinogalaktaanin erottamiseen ei kuitenkaan vaadita ankaria olosuhteita, vaan yleisimmin siihen riittää uutto vedellä. Kalvosuodatus puolestaan on hyvä keino hemiselluloosan talteenottoon uuttoliuoksista. Tässä työssä tarkasteltiin arabinogalaktaanin erotusta siperianlehtikuusesta uuttokokein. Saadut uuttoliuokset konsentrointiin ja puhdistettiin kalvosuodatusmenetelmillä. Lisäksi tutkittiin eristetyn arabinogalaktaanin käyttöä kemiallisen muokkauksen lähtöaineena, missä pyrkimyksenä oli etenkin in situ -modifiointi suoraan uuttoliuoksessa oleville yhdisteille. Uuttokokeilla saatiin kuitenkin vain pieni osa lehtikuusen arabinogalaktaanista erotetuksi. Myös kalvosuodatusvaiheen aikana menetettiin osa uuttoliuosten arabinogalaktaanista. Koska arabinogalaktaanipitoisuus uuttoliuoksissa jäi hyvin alhaiseksi, in situ -modifiointeja oli vaikea saada onnistumaan. Uutto-olosuhteiden lisätutkimuksella sekä kiinnittämällä erityistä huomiota suodatuskalvojen valintaan voitaneen pitoisuutta nostaa ja saada lisämateriaalia kemiallista muokkausta varten.

Semi-selective medium for Fusarium graminearum detection in seed samples

Fungi of the genus Fusarium cause a variety of difficult to control diseases in different crops, including winter cereals and maize. Among the species of this genus Fusarium graminearum deserves attention. The aim of this work was to develop a semi-selective medium to study this fungus. In several experiments, substrates for fungal growth were tested, including fungicides and antibiotics such as iprodiona, nystatin and triadimenol, and the antibacterial agents streptomycin and neomycin sulfate. Five seed samples of wheat, barley, oat, black beans and soybeans for F. graminearum detection by using the media Nash and Snyder agar (NSA), Segalin & Reis agar (SRA) and one-quarter dextrose agar (1/4PDA; potato 50g; dextrose 5g and agar 20g), either unsupplemented or supplemented with various concentrations of the antimicrobial agents cited above. The selected components and concentrations (g.L-1) of the proposed medium, Segalin & Reis agar (SRA-FG), were: iprodiona 0.05; nystatin 0,025; triadimenol 0.015; neomycin sulfate 0.05; and streptomycin sulfate, 0.3 added of ¼ potato sucrose agar. In the isolation from seeds of cited plant species, the sensitivity of this medium was similar to that of NSA but with de advantage of maintaining the colony morphological aspects similar to those observed in potato-dextrose-agar medium.

Decomposition of corn and soybean residues under field conditions and their role as inoculum source

Necrotrophic parasites of above-ground plant parts survive saprophytically, between growing seasons in host crop residues. In an experiment conducted under field conditions, the time required in months for corn and soybean residues to be completely decomposed was quantified. Residues were laid on the soil surface to simulate no-till farming. Crop debris of the two plant species collected on the harvesting day cut into pieces of 5.0cm-long and a 200g mass was added to nylon mesh bags. At monthly intervals, bags were taken to the laboratory for weighing. Corn residues were decomposed within 37.0 months and those of soybean, within 34.5 months. Hw main necrotrophic fungi diagnosed in the corn residues were Colletotrichum gramicola, Diplodia spp. and Gibberella zeae, and those in soybeans residues were Cercospora kikuchii, Colletotrichum spp, Glomerella sp. and Phomopsis spp. Thus, those periods shoulb be observed in crop rotation aimed at to eliminating contaminated residues and, consequently, the inoculum from the cultivated area.

Use of botanical extracts, cassava wastewater and nematicide for the control of root-knot nematode on carrot

Aqueous extracts of several plant species have shown promising in controlling root-knot nematode, Meloidogyne incognita (Kofoid & White), one of the most limiting agents for carrot cultivation. The current study evaluated the effect of aqueous extracts from seven botanical species applied to 40, 50, 60, 70 and 80 days after sowing 'Nantes' carrots in soil infested with root-knot nematode. Three other treatments included cassava wastewater, distilled water (control), which were applied in the same periods of the extracts application, in addition to carbofuran 50G (80Kg/ha), which was applied once at 60 days after carrot sowing. Evaluations were performed at 90 days after inoculation to determine shoot and root fresh weight, as well as the diameter and the length of principal roots and the number of galls on primary and secondary roots. Plants treated with cassava wastewater, extracts of Ricinus communis L. seeds, Crotalaria juncea L. seeds, R. communis leaves + branches + fruits, Chenopodium ambrosioides L. leaves + branches + inflorescences and Azadirachta indica A. Juss. seeds showed the highest rates of total weight (root + shoot) and shoot weight. The extract of R. communis leaves + branches + fruits provides the highest total root weight and principal root diameter. Cassava wastewater and extracts of R. communis seeds provided the highest principal root weight. The extract of R. communis seeds and cassava wastewater can be considered promising for the alternative control of M. incognita.

Macrophomina phaseolina: density and longevity of microsclerotia in soybean root tissues and free on the soil, and competitive saprophytic ability

In field experiments, the density of Macrophomina phaseolina microsclerotia in root tissues of naturally colonized soybean cultivars was quantified. The density of free sclerotia on the soil was determined for plots of crop rotation (soybean-corn) and soybean monoculture soon after soybean harvest. M. phaseolina natural infection was also determined for the roots of weeds grown in the experimental area. To verify the ability of M. phaseolina to colonize dead substrates, senesced stem segments from the main plant species representing the agricultural system of southern Brazil were exposed on naturally infested soil for 30 and 60 days. To quantify the sclerotia, the methodology of Cloud and Rupe (1991) and Mengistu et al. (2007) was employed. Sclerotium density, assessed based on colony forming units (CFU), ranged from 156 to 1,108/g root tissue. Sclerotium longevity, also assessed according to CFU, was 157 days for the rotation and 163 days for the monoculture system. M. phaseolina did not colonize saprophytically any dead stem segment of Avena strigosa,Avena sativa,Hordeum vulgare,Brassica napus,Gossypium hirsutum,Secale cereale,Helianthus annus,Triticosecalerimpaui, and Triticum aestivum. Mp was isolated from infected root tissues of Amaranthus viridis,Bidens pilosa,Cardiospermum halicacabum,Euphorbia heterophylla,Ipomoea sp., and Richardia brasiliensis. The survival mechanisms of M. phaseolina studied in this paper met the microsclerotium longevity in soybean root tissues, free on the soil, as well as asymptomatic colonization of weeds.