Propagação vegetativa de Hyptis leucocephala Mart. ex Benth. e Hyptis platanifolia Mart. ex Benth. (Lamiaceae) / Vegetative propagation of Hyptis leucocephala Mart. ex Benth. and Hyptis platanifolia Mart. ex Benth

O gênero Hyptis (Lamiaceae) apresenta metabolismo especial de notável variabilidade, possuindo predominância de óleos essenciais, que têm muito valor junto a diversas comunidades que utilizam essas plantas pelas propriedades terapêuticas. Diversos estudos com esse gênero têm demonstrado que os óleos essenciais apresentam propriedades antimicrobiana, antifúngica, citotóxica, antiinflamatória, anti-HIV e inseticida, entretanto, poucos são os estudos voltados para a exploração sustentável dessas espécies. O objetivo desse trabalho foi avaliar o efeito de diferentes tipos de estaca e diferentes concentrações de ácido indolbutírico (AIB) sobre a taxa de sobrevivência, crescimento e enraizamento de estacas de Hyptis leucocephala Mart. ex Benth. e Hyptis platanifolia Mart. ex Benth., espécies endêmicas do semi-árido nordestino cujo valor medicinal tem sido amplamente comprovado. O experimento teve duração de quatro meses. Foram utilizadas estacas apicais, médio-apicais, médio-basais e basais tratadas com soluções de 0, 1000, 2000 e 4000 mg L-1 de ácido indolbutírico (AIB), durante 5 minutos. A utilização de estacas apicais, médio/apicais e médio/basais induzidas com 2000 e 4000 mg L-1 de AIB possibilitaram melhores resultados para propagação vegetativa de Hyptis leucocephala. Para Hyptis platanifolia os melhores resultados foram obtidos com a utilização de estacas médio/basais e basais tratadas com AIB na concentração de 2000 e 4000 mg L-1.

The genus Hyptis (Lamiaceae) has a special metabolism with remarkable variability and predominance of essential oils of great value to the various communities that use these plants due to their therapeutic properties. A number of studies on this genus have demonstrated that its essential oils present antimicrobial, antifungal, cytotoxic, anti-inflammatory, anti-HIV and insecticidal activities. However, few studies have focused on the sustainable exploitation of these species. The aim of this study was to evaluate the effect of different types of cuttings and different concentrations of indolebutyric acid (IBA) on the survival, growth and rooting rates of cuttings from Hyptis leucocephala Mart. ex Benth. and Hyptis platanifolia Mart. ex Benth., species endemic to the semi-arid region of Northeastern Brazil and with largely proven medicinal value. The experiment lasted four months. Apical, middle-apical, middle-basal and basal cuttings were treated with 0, 1000, 2000 and 4000 mg L-1 IBA solutions for 5 min. The use of apical, middle-apical and middle-basal cuttings induced by 2000 and 4000 mg L-1 IBA led to the best results for vegetative propagation of H. leucocephala. For H. platanifolia, the best results were obtained using middle-basal and basal cuttings treated with IBA at 2000 and 4000 mg L-1.

Abordagem etnobotânica sobre plantas medicinais citadas por populações do entorno de uma unidade de conservação da caatinga do Rio Grande do Norte, Brasil / Ethnobotanical approach to medicinal plants mentioned by people from the environs of a caatinga conservation unit in Rio Grande do Norte, Brazil

As Caatingas, único Bioma exclusivamente brasileiro, têm sofrido grande extrativismo dos recursos, com perdas de diversidade biológica associadas ao fornecimento de madeira e extratos vegetais. As consequências impactantes sobre este Bioma têm levado a busca de estratégias para conservação, como a criação de Unidades de Conservação (UCs), a exemplo da Estação Ecológica do Seridó (ESEC Seridó), localizada no Estado do Rio Grande do Norte, cujas comunidades do entorno mantêm forte relação com esta ESEC. Como o mau uso dos recursos da Caatinga tem sido fortemente associado às necessidades das populações que ali habitam, este trabalho objetivou o estudo da percepção ambiental das comunidades do entorno da ESEC Seridó, focando sobre o conhecimento dessas sobre plantas de uso medicinal. Contabilizaram-se 48 espécies de plantas nativas e 39 exóticas, sendo 31 e 14 com propriedades medicinais, respectivamente. Foi constatado um rico conhecimento dessas comunidades sobre as plantas presentes nessa região, e a riqueza desses resultados são relevantes para futuras estratégias de gestão nesta Unidade de Conservação.

Caatinga, the only exclusively Brazilian biome, has suffered exploitation of its natural resources, with loss of biodiversity associated with wood and plant extract supply. The resulting impacts on this biome have led to the search for strategies for its conservation like the establishment of Conservation Units (CUs), such as the Ecological Station of Seridó (ESEC Seridó) located in Rio Grande do Norte State. The human communities in ESEC Seridó environs maintain a strong relationship with this conservation unit. Considering that the misuse of caatinga resources has been strongly linked to the needs of its inhabitants, this work aimed to investigate the environmental perception of communities from the environs of ESEC Seridó, focusing on the popular knowledge about plants of medicinal use. This investigation recorded 48 native and 39 exotic species, of which 31 and 14 species, respectively, had medicinal properties. The communities surveyed showed a deep knowledge of the plants found in that region and the wealth of these results is relevant for future management strategies in this Conservation Unit.

Estacas de diferentes diâmetros na propagação de Lippia alba (Mill.) N.E.Br. - Verbenaceae / Different diameters of cuttings on the propagation of Lippia alba (Mill.) N.E.Br. - Verbenaceae

Este trabalho teve por objetivo avaliar o efeito de diferentes diâmetros de estacas na propagação de Lippia alba. Foram testadas estacas de 25 cm de comprimento, com diâmetros de 0,3-0,5 cm; 0,6-0,9 cm e 1-1,2 cm. Aos 30 e 60 dias após o plantio das estacas foram determinadas as características biométricas, como porcentagem de enraizamento, número de brotos, comprimento dos brotos, massas secas de brotos, estacas, raízes e total. Todos os diâmetros de estacas apresentaram altas taxas de enraizamento aos 30 dias, comprovando que a L. alba é uma espécie de fácil propagação por estaquia. A produção de mudas de L. alba deve ser realizada com estacas entre 1-1,2 cm de diâmetro, que foi superior aos outros diâmetros testados na maioria das características biométricas determinadas.

The aim of this work was to study the effect of different diameters of cuttings on the propagation and growth of Lippia alba. Cuttings of 25 cm length, with three different diameters: 0.3-0.5 cm, 0.6-0.9 cm and 1-1.2 cm, were tested. At 30 and 60 days after the planting of cuttings, the following biometric parameters were determined rooting percentage; number of buds, length of buds; dry matter of buds, cuttings and roots; and total dry matter. All diameters of cuttings presented high rates of rooting after 30 days, confirming that L. alba is an easy-to-root species. L. alba seedling production should use cuttings between 1-1.2 cm diameter, which was better than the others diameters considering most of the tested parameters.

Plant growth inhibitory activity of N, N´-di-(4-R-phenyl)-alkanediamides / Actividad inhibitoria de crecimiento de plantas de N, N’-di-(4-R-phenyl)-alcanodiamidas

Diamides are a class of metabolites that occurring in some Meliaceae plants, in Aglaia spp for example, with an ample body of biological activities, being insecticidal and herbicidal two of the most important. In our program of search for botanical pesticides, a series of N,N´-di-(4-R-phenyl)-alkanediamides was evaluated for its herbicidal activity. Many of the analogues tested exhibited moderate to good herbicidal activity both pre-emergence and post-emergence and have been found to inhibit energetic metabolism of pre-emergence weeds. The structure-activity relationships were probed by substitution on the benzene ring. Among the variations investigated, it was found that maximal herbicidal activity was obtained by substitution of –F, -CN and -Br at the aromatic portion and by n=2 of the aliphatic long chain. This last number of carbons (n=2) substitution was the key for the inhibitory activity.

Diamidas son una clase de metabolitos que estan presentes en plantas perteneciente a la familia de la Meliaceas, en Aglaia por ejemplo, poseen un amplio cuerpo de actividades biologicas, siendo la insecticida y la herbicida dos de las mas importantes. En nuestro programa para la busqueda de pesticidas botanicos, una serie de N,N’-di-(4-R-phenyl)-alkanodiamidas se evaluo para su actividad herbicida. Muchos de los analogos exhibieron desde buenas a moderadas actividades, tanto como pre-emergentes como post-emergentes y ademas se encontro que inhiben el metabolismo pre-emergente energetico de malezas. La relacion estructura-actividad fue probada por sustitución sobre al anillo aromatico. Entre las variaciones investigadas, se encontro que la maxima actividad herbicida se obtuvo por sustitución de F, CN y Br en la porcion aromatica y por n=2 del largo de la cadena alifatica. Este ultimo numero de carbonos de sustitución (n=2) fue clave para la actividad inhibitoria.

Diversidad de la vegetación durante su recuperación tras una creciente extraordinaria del Río Paraná Medio (Argentina)

Diversity of vegetation during its recovery from a catastrophic flood of the Medium Paraná River (Argentina). River floodplains have a high biological diversity that is intensely influenced by vegetation dynamics, changes in space and time scales, and the river`s hydrological regime. The vegetation composition of the medium and lower Paraná River has been analyzed previously, with different approaches and criteria that cannot be compared. The aim of this study is to analyze the diversity of the herbaceous vegetation over long time spans, from its regeneration after a catastrophic flood to its recovery, in the North and South sites of the flooding valley of the Medium Paraná River. The first sampling of a pioneer community was performed after the 1982-83 catastrophic flood, and included the surveillance of two plots in two successive recovery stages. Floristic composition and cover-abundance of all species were recorded per plot. Floristic richness, using jackknife, Shannon and Hurlbert diversity and Simpson dominance curves were calculated for each site and for each survey, using EcoSim (software). Floristic richness was higher in the North of Medium Paraná, while dominance was higher in the South. Diversity indexes did not varied significantly and resulted in relatively stable values, because its components compensate each other. Rev. Biol. Trop. 58 (2): 707-716. Epub 2010 June 02.

La diversidad florística en las planicies de inundación está ligada a la dinámica de la vegetación, por lo que su comprensión depende de las escalas espacial y temporal el régimen hidrológico del río. La planicie de inundación del Río Paraná, Argentina, tiene una alta diversidad biológica, aolo conocida a través de estudios puntuales no comparables entre si. El objetivo de esta contribución fue analizar la diversidad de la vegetación herbácea a largo plazo, desde su reinstalación después de una inundación catastrófica hasta su recuperación, en dos áreas (norte y sur) del Paraná Medio. Cuando el nivel del agua disminuyó después de la creciente catastrófica de 1982-83, se realizó el primer muestreo en una comunidad pionera, y en años posteriores, otros dos en etapas avanzadas de recuperación de la vegetación. Se registraron las especies presentes y se estimó su abundanciacobertura. Se calcularon las curvas de riqueza florística, de diversidad de Shannon y Hurlbert y de dominancia de Simpson en ambas áreas, utilizando el programa EcoSim. La riqueza florística resultó mayor en el norte del Paraná Medio, mientras que la dominancia lo fue en el sur. Los índices de diversidad no reflejan estas variaciones, pues al compensarse entre sí sus componentes, dan como resultado valores relativamente estables.

Adubação orgânica na produção de biomassa de plantas, teor e qualidade de óleo essencial de orégano (Origanum vulgare L. ) em cultivo protegido / Organic fertilization on phytomass production and essential oil content and quality of oregano (Origanum vulgare L. ) under protected cultivation

Origanum vulgare L., conhecida como orégano, é considerada planta condimentar largamente usada na culinária. No Brasil poucas são as pesquisas com esta espécie visando maximização das técnicas de cultivo. Objetivou-se avaliar os efeitos de diferentes doses dos adubos orgânicos bovino e aves no crescimento de plantas, teor de clorofila, teor, rendimento e qualidade do óleo essencial de orégano cultivado sob estufa. Foram conduzidos dois ensaios, sendo um com esterco bovino e o outro com esterco de aves (Poedeira). Plantas de orégano (Origanum vulgare L.) foram cultivadas em vasos de 10 L submetidas aos seguintes tratamentos: Ensaio I: Esterco bovino: 1) Solo sem adubação (controle); 2) solo + 3,0 kg m-2 de esterco bovino; 3) solo + 6,0 kg m-2 de esterco bovino; 4) solo + 9,0 kg m-2 de esterco bovino; 5) solo + 12,0 kg m-2 de esterco bovino; Ensaio II - Esterco de aves: 1) solo sem adubação (Controle); 2) solo + 1,5 kg m-2 de esterco de galinha; 3) solo + 3,0 kg m-2 de esterco de galinha; 4) solo + 4,5 kg m-2 de esterco de galinha e 5) solo + 6,0 kg m-2 de esterco de galinha. Ambos os ensaios foram conduzidos em delineamento blocos ao acaso com 4 repetições e a parcela experimental composta de 4 vasos. Foi observado que as doses de adubos bovino e avícola influenciaram significativamente no crescimento das plantas, rendimento e composição química do óleo essencial de orégano.

Origanum vulgare L., known as oregano or wild marjoram, is an aromatic plant widely used in cookery. In Brazil, there are few studies with this species aimed at improving the cultivation techniques. The present study was carried out to evaluate the effect of different levels of cattle and chicken organic manure on plant growth, chlorophyll content, besides essential oil content, yield and quality of oregano grown in a greenhouse. Two assays were carried out, one of them used cattle manure and the other, chicken manure (Hen). Oregano (Origanum vulgare L.) plants were grown in 10L-pots and subjected to the following treatments: Assay I: Cattle manure: 1) Soil without fertilization (control); 2) Soil + 3.0 kg m-2 cattle manure; 3) Soil + 6.0 kg m-2 cattle manure; 4) Soil + 9.0 kg m-2 cattle manure; and 5) Soil + 12.0 kg m-2 cattle manure; Assay II: Chicken manure: 1) Soil without fertilization (control); 2) Soil + 1.5 kg m-2 chicken manure; 3) Soil + 3.0 kg m-2 chicken manure; 4) Soil + 4.5 kg m-2 chicken manure; and 5) Soil + 6.0 kg m-2 chicken manure. The experimental design for both assays was in randomized blocks with four replicates and four pots per plot. Cattle and chicken manure levels significantly influenced oregano plant growth besides essential oil yield and chemical composition.

Cold resistance in plants: a mystery unresolved

Herbaceous temperate plants are capable of developing freezing tolerance when they are exposed to low nonfreezing temperatures. Acquired freezing tolerance involves extensive reprogramming of gene expression and metabolism. Recent full-genome transcript profiling studies, in combination with mutational and transgenic plant analyses, have provided a snapshot of the complex transcriptional network that operates under cold stress. The changes in expression of hundreds of genes in response to cold temperatures are followed by increases in the levels of hundreds of metabolites, some of which are known to have protective effects against the damaging effects of cold stress. Genetic analysis has revealed important roles for cellular metabolic signals, and for RNA splicing, export and secondary structure unwinding, in regulating cold-responsive gene expression and chilling and freezing tolerance. These results along with many of the others summarized here further our understanding of the basic mechanisms that plants have evolved to survive freezing temperatures. In addition, the findings have potential practical applications, as freezing temperatures are a major factor limiting the geographical locations suitable for growing crop and horticultural plants and periodically account for significant losses in plant productivity. Although, great progress has been made in the field but lacunae still remain since it appears that the cold resistance is more complex than perceived and involves more than one pathway.

AgNO3: a potential regulator of ethylene activity and plant growth modulator

The aim of this review is to critically analyze the role of silver nitrate (AgNO3) in modulating plant growth and development. In recent years, basic studies on ethylene regulation opened new vistas for applied research in the area of micro-propagation, somatic embryogenesis, in vitro flowering, growth promotion, fruit ripening, and sex expression. Silver nitrate has proved to be a very potent inhibitor of ethylene action and is widely used in plant tissue culture. Few properties of silver nitrate such as easy availability, solubility in water, specificity and stability make it very useful for various applications in exploiting plant growth regulation and morphogenesis in vivo and in vitro. Silver ion mediated responses seem to be involved in polyamines, ethylene- and calcium- mediated pathways, and play a crucial role in regulating physiological process including morphogenesis. The molecular basis for regulation of morphogenesis under the influence of silver nitrate is completely lacking. This review compiles published reports of silver nitrate-mediated in vitro and in vivo studies and focuses on fundamental and applied aspects of plant growth modulation under the influence of silver nitrate.

Comparison of plant growth-promotion with Pseudomonas aeruginosa and Bacillus subtilis in three vegetables / Comparação da promoção de crescimento de plantas por Pseudomonas aeruginosa e Bacillus subtilis em três vegetais

Our objective was to compare some plant growth promoting rhizobacteria (PGPR) properties of Bacillus subtilis and Pseudomonas aeruginosa as representatives of their two genera. Solanum lycopersicum L. (tomato), Abelmoschus esculentus (okra), and Amaranthus sp. (African spinach) were inoculated with the bacterial cultures. At 60 days after planting, dry biomass for plants treated with B. subtilis and P. aeruginosa increased 31 percent for tomato, 36 percent and 29 percent for okra, and 83 percent and 40 percent for African spinach respectively over the non-bacterized control. Considering all the parameters tested, there were similarities but no significant difference at P < 0.05 between the overall performances of the two organisms.

Nosso objetivo foi comparar as propriedades PGPR (rizobactérias promotoras de crescimento de plantas) de Bacillus subtilis e Pseudomonas aeruginosa. Solanum licopersicum (tomate), Asbelmoschus esculentus (ocra) e Amaranthus sp (espinafre africano) foram inoculados com as culturas bacterianas. Após 60 dias de plantio, a biomassa seca das plantas tratadas com B.subtilis e P. aeruginosa aumentou 31 por cento para o tomate, 36 por cento e 29 por cento para ocra, e 83 por cento e 40 por cento para espinafre africano, respectivamente, em comparação com o controle não inoculado. Considerando os parâmetros testados, o desempenho dos dois microrganismos foi similar, sem diferença estatisticamente significativa (p< 0,05).

Applicability of leachates originating from solid-waste landfills for irrigation in landfill restoration projects.

Since, landfill areas are still the most widely used solid waste disposal method across the world, leachate generated from landfills should be given importance. Leachate of landfills exerts environmental risks mostly on surface and groundwater with its high pollutant content, which may cause unbearable water quality. This leads to the obligation for decontamination and remediation program to be taken into progress for the landfill area. Among a number of alternatives to cope with leachate, one is to employ the technology of phytoremediation. The main objective of this study was to determine the N accumulation ratios and the effects of landfill leachate in diluted proportions of chosen ratios (as 1/1, 1/2, 1/4, 0), on the growth and development of Cynodon dactylon, Stenotaphrum secundatum, Paspalum notatum, Pennisetum clandestinum, Mentha piperita, Rosmarinus officinalis, Nerium oleander, Pelargonium peltatum and Kochia scoparia species. In order to simulate the actual conditions of the landfill, soil covering the landfill is taken and used as medium for the trials. The study showed that S. secundatum, K. scoparia and N. oleander species had an impressive survival rate of 100%, being irrigated with pure leachate, while the others' survival rates were between 0 to 35% under the same conditions. As expected, application of leachate to the plants caused an increase in the accumulation of N, in the upper parts of all plants except P. peltatum. The highest N content increase was observed at S. Secundatum set, accumulating 3.70 times higher than its control set, whereas P. clandestinum value was 3.41 times of its control set.

Can we predict dispersal guilds based on the leaf-height-seed scheme in a disjunct cerrado woodland? / Podemos prever guildas de dispersão com base no esquema folha-altura-semente em um cerrado sensu stricto disjunto?

Although there have been advances in methods for extracting information about dispersal processes, it is still very difficult to measure them. Predicting dispersal groups using single readily-measured traits would facilitate the emergence of instructive comparisons among ecological strategies of plants and offer a path towards improved synthesis across field experiments. The leaf-height-seed scheme consists of three functional traits: specific leaf area, plant canopy height, and seed mass. We tested, applying logistic regression analysis, whether these traits are potential predictors of dispersal guilds in a disjoint cerrado woodland site in southeastern Brazil. According to our results, none of the plant traits studied could predict dispersal guild; this means that abiotically and biotically dispersed species showed similar values of specific leaf area, height, and seed mass. The species of both guilds exhibited sclerophylly, probably a result of the typical soil nutrient deficiency of cerrado, which also may have placed constraints upon plant canopy height regardless of the dispersal mode. In the cerrado, some abiotically dispersed trees might present higher than expected seed mass as support to the investment in high root-to-shoot ratio at the seedling stage. Seeds of bird-dispersed species are limited in size and mass because of the small size of most frugivorous birds. Since soil nutrient quality might contribute to the similarity between the dispersal guilds regarding the three traits of the scheme, other plant traits (e.g., root depth distribution and nutrient uptake strategy) that detail the former should be considered in future predictive studies.

Embora tenham ocorrido avanços nos métodos de aquisição de informações sobre os processos de dispersão, ainda é difícil medi-los. Predizer grupos de dispersão usando atributos simples e práticos facilitaria o aparecimento de comparações instrutivas entre as estratégias ecológicas das plantas e ofereceria um caminho em direção à síntese efetiva de experimentos de campo. O esquema Folha-Altura-Semente consiste em três atributos funcionais: área foliar específica, altura e massa da semente. Testamos, aplicando análise de regressão logística, se esses atributos são potenciais previsores das guildas de dispersão em uma área disjunta de cerrado sensu stricto no Sudeste brasileiro. Segundo os nossos resultados, nenhum dos atributos estudados pôde prever a guilda de dispersão. Isso significa que espécies abiótica e bioticamente dispersas apresentaram valores similares de área foliar específica, altura e massa da semente. As espécies de ambas as guildas exibiram esclerofilia, provavelmente um resultado da deficiência nutricional típica dos solos do cerrado, o que, por sua vez, pode ter limitado à altura das espécies independentemente do seu modo de dispersão. No cerrado, algumas árvores com dispersão abiótica podem apresentar sementes mais pesadas do que o esperado devido ao investimento em elevada razão raiz-caule no estádio de plântula. Sementes de espécies ornitocóricas são limitadas no seu tamanho e massa por causa do reduzido tamanho da maioria das aves frugívoras. Uma vez que a qualidade nutricional do solo do cerrado pode contribuir com a similaridade entre as guildas de dispersão no que diz respeito aos três atributos do esquema, outros atributos (por ex., distribuição da profundidade da raiz e estratégia de captação de nutrientes) que detalhem a primeira devem ser considerados em estudos futuros.

Impacts of different compost types application on soil fertility and plant growth

This study aims at evaluating the impacts of applying different compost types produced in Alexandria city on the soil and plant. Composting is the biological decomposition and stabilization of organic substrates. It is a means of converting objectionable wastes, such as sewage sludge, garbage, organic trash, food processing wastes and farm manures into materials suitable for application to land. Sandy soils and four types of compost with different rates were applied; composted sewage sludge, Composted domestic solid waste, composted plant residues, and composted animal manure. The Tested plant was Wheat [Giza 75]. Pot experiments were carried out at lab. the results revealed that application of different types of compost to sandy soil cultivated with wheat plant increased soil salinity [EC], organic matter [CM], available nitrogen, and trace element [Fe, Mn, Zn, Cu, Cr, and Pb] contents while decreased pH and available phosphorus. As the soil treated with different compost types were enriched with macro and micronutrients, the fresh plants and oven-dried weights of the plants of treated soil were higher than those of plants of untreated control soil. It is clear that sewage sludge and domestic solid wastes composts application indicated a highest plant yield among other compost types. This study recommended Application of sewage sludge compost must be under special control, Aplication of domestic solid wastes could be used at the rate of 10 and 20% for sandy soil, plant residues compost could be applied on sandy soil, at the rate of 10% only for cultivation of all crops, and Application of animal manure compost could be applied at the range of 20-30% in case of sandy soil for all crops

Multiplicação in vitro de Aspidosperma ramiflorum Muell. Arg. (Apocynaceae) / In vitro multiplication of Aspidosperma ramiflorum Muell. Arg. (Apocynaceae)

O presente estudo relata um método simples e promissor para multiplicação in vitro de Aspidosperma ramiflorum, uma espécie encontrada no sudeste do Brasil e seriamente ameaçada de extinção, utilizada com propósitos medicinais e como fonte de compostos que podem ser usados para desenvolver novos fármacos sintéticos. O trabalho teve como objetivo o estabelecimento de um protocolo de multiplicação in vitro de Aspidosperma ramiflorum (guatambu), a partir de segmentos apicais de material juvenil originários de plântulas obtidos a partir de sementes. A avaliação da multiplicação in vitro foi realizada em meio de cultura Woody Plant Médium (WPM), suplementado com concentrações variadas de ácido naftalenoacético (ANA) e 6-Benzilaminopurina (6-BAP). A multiplicação de A. ramiflorum foi positivamente influenciada principalmente nas combinações aonde as concentrações de 6-BAP foram relativamente maiores do que as do ANA, nessas concentrações houve a indução de múltiplas brotações.

The present study described a simple and promissory method for in vitro multiplication of Aspidosperma ramiflorum, a species found in the South of Brazil and seriously extinction menaced. The method was used for medicinal proposes and as a source of compounds to develop new synthetic drugs. The objective of this work was to establish an in vitro multiplication protocol of Aspidosperma ramiflorum (guatambu), from apical segments of juvenile material of plantlets obtained from seeds. The in vitro multiplication evaluation was done in WPM medium, supplemented with variable concentrations of Naphthalene acetic acid (NAA) and 6- Benzyl aminopurine (6-BAP). The multiplication of A. ramiflorum was positively influenced mainly in the combinations when 6-BAP concentrations were relatively higher than NAA. In these concentrations multiple shoots were induced.

Genetic diversity in two variants of Orobanche gracilis Sm. [var. gracilis and var. deludens (Beck) A. Pujadas] (Orobanchaceae) from different regions of Spain

The pattern of genetic variation among populations of two Orobanche gracilis Sm. taxa (var. gracilis and var. deludens (Beck) A. Pujadas) from Northern and Southern Spain growing on different hosts was analysed using RAPD markers. The diversity analysis within populations revealed a higher level of diversity in the populations from the North when compared to the Southern ones. The results of principal co-ordinate analysis (PCoA) based on Dice distances among samples clearly established the separation of samples according to the taxonomical variety and the geographical origin of each population. The Southern populations of both var. gracilis and var. deludens were more differentiated among them than those of var. gracilis from the North. The analysis of molecular variance (AMOVA) indicated that the lowest level of population differentiation was found in O. gracilis var. gracilis from the North, whereas in the case of O. gracilis var. deludens from the South most of the genetic diversity was attributable to differences among populations. Possible explanations for the distribution of variation in these populations are discussed.

Eleocharis R.Br. (Cyperaceae) no Estado do Rio de Janeiro, Brasil / Eleocharis R. Br. (Cyperaceae) in Rio de Janeiro State, Brasil

Foi realizado o levantamento das espécies de Eleocharis (Cyperaceae) no Estado do Rio de Janeiro - Brasil, a partir de exsicatas depositadas nos principais herbários do Estado (FCAB, GUA, HB, HUNI, R, RB, RBR, RFA, RUSU), assim como coletadas em excursões a ecossistemas aquáticos na área de estudo, entre novembro de 1998 a setembro de 2003. O gênero Eleocharis está representado no Estado do Rio de Janeiro por 19 espécies: Eleocharis acutangula (Roxb.) Schult., E. debilis Kunth, E. elongata Chapm., E. equisetoides (Elliott) Torr., E. filiculmis Kunth, E. flavescens (Poir.) Urb., E. geniculata (L.) Roem. & Schult., E. interstincta (Vahl) Roem. & Schult., E. maculosa (Vahl) Roem. & Schult., E. minarum Boeck.*, E. minima Kunth, E. montana (Kunth) Roem. & Schult., E. mutata (L.) Roem. & Schult., E. nana Kunth, E. pachystyla (C. Wright) C. B. Clarke*, E. radicans (Poir.) Kunth*, E. sellowiana Kunth, E. squamigera Svenson e E. subarticulata (Nees) Boeck (*espécies raras no Estado do Rio de Janeiro). São apresentadas chave de identificação, descrições, ilustrações, informações adicionais de natureza ecológica e distribuição geográfica das espécies de Eleocharis do Estado do Rio de Janeiro.

A floristic inventory of the species of Eleocharis (Cyperaceae) from Rio de Janeiro State - Brazil was made. This research included material from most important Herbaria of Rio de Janeiro (FCAB, GUA, HB, HUNI, R, RB, RBR, RFA, RUSU) as well as plants collected during expeditions to aquatic ecosystems of Rio de Janeiro, between November 1998 and September 2003. The genus Eleocharis is represented in the area by 19 species: Eleocharis acutangula (Roxb.) Schult., E. debilis Kunth, E. elongata Chapm., E. equisetoides (Elliott) Torr., E. filiculmis Kunth, E. flavescens (Poir.) Urb., E. geniculata (L.) Roem. & Schult., E. interstincta (Vahl) Roem. & Schult., E. maculosa (Vahl) Roem. & Schult., E. minarum Boeck.*, E. minima Kunth, E. montana (Kunth) Roem. & Schult., E. mutata (L.) Roem. & Schult., E. nana Kunth, E. pachystyla (C. Wright) C. B. Clarke*, E. radicans (Poir.) Kunth*, E. sellowiana Kunth, E. squamigera Svenson, and E. subarticulata (Nees) Boeck. (*species rare in Rio de Janeiro state). A key of identification, descriptions of species, illustrations, and notes on ecological features and geographical distribution are presented.

Nuevas perspectivas para el estudio de asignacion de biomasa y su relacion con el funcionamiento de plantas en ecosistemas neotripales / New Perspectives to Study the Biomass Allocation and its Relationship with the Functioning of Plants in Neotropical Ecosystems

Cómo responden las plantas a la variabilidad en la disponibilidad de los recursos abióticos, es un tema central en estudios de fisiología ecológica. Varios modelos de partición óptima han sugerido un balance funcional en la biomasa asignada al vástago y la raíz con la siguiente predicción: “las plantas cambiarían su asignación de biomasa hacia el vástago si la ganancia de carbono de la parte aérea de la planta es afectada por un nivel bajo de recursos sobre el suelo, tal como luz o CO2. Igualmente, las plantas cambiarían su asignación hacia la raíz si el nivel de los recursos del suelo es bajo, tal como nutrientes y agua”. Estos cambios en la asignación pueden ser considerados como adaptativos, ya que permiten a la planta capturar más de aquel recurso que limita fuertemente su crecimiento. En este trabajo, discutimos algunos esquemas metodológicos que a través de la descripción y análisis de la asignación de biomasa pretenden probar dicha predicción. Enfatizamos que la conclusión extraída en contra o a favor de la predicción se fundamenta en la interpretación del término plasticidad, conllevando recientemente al uso de metodologías que sugieren que la predicción no se cumple en respuesta a la disponibilidad de algunos recursos. Proponemos la utilización de un protocolo de investigación para estudiar los patrones de asignación de biomasa y sugerimos una metodología para cuantificar la plasticidad de diferentes genotipos desde un punto de vista discreto.

Uso de bioestimulante na formação de mudas de maracujazeiro amarelo / Use of bioestimulant in yellow passion fruit seedlings

A produção de mudas de alta qualidade torna-se uma estratégia importante para o sucesso de uma cultura. Desta forma, o presente trabalho teve como objetivo avaliar o efeito de diferentes doses de bioestimulante Stimulate na formação de mudas de maracujazeiro. O experimento foi conduzido em casa de vegetação, em delineamento experimental em blocos casualizados, com parcelas subdivididas no tempo, com seis tratamentos e quatro repetições, sendo cada parcela composta de 24 plantas. Os tratamentos foram constituídos de diferentes doses de bioestimulante: (água destilada), 4, 12, 16, e 20 mL kg-1 sementes. Foram coletadas duas plantas por parcela aos 15, 22, 29, 36, 43 e 50 dias após a emergência. As características avaliadas foram altura de plantas, área foliar, massa seca de folhas, parte aérea, raízes, massa seca total, razão raiz/parte aérea, taxa de crescimento absoluto e relativo, taxa assimilatória líquida, razão de área foliar e área foliar específica. Verificou-se efeito positivo do bioestimulante sobre a maioria das variáveis avaliadas, em relação à testemunha. Doses entre 4 e 6 mL de Stimulate kg-1 de sementes promoveram maior equilíbrio entre o sistema radicular e a parte aérea, o que pode favorecer o estabelecimento da muda no campo

The production of seedlings of high quality becomes an important strategy for the success of a crop.The present research had the objective of evaluating the effect of different bioestimulant doses,Stimulate®, in the formation of passion fruit seedlings. The experiment was carried out in greenhouseconditions, in randomize complete blocks experimental design with six treatments and four replications,with 24 plants per plots. The treatments were constituted of different bioestimulante doses: 0 (distilledwater), 4, 12, 16 and 20 mL kg-1 seeds. Plants were collected 15, 22, 29, 36, 43 and 50 days after theemergency. Evaluations were plant height, leaf area, dries mass of leaves, shoot, root and total dry mass;root/shoot relation, absolute and relative growth rate, net assimilate rate, leaf area ratio and specific leafarea. Positive effect of the bioestimulant was verified on most of the appraised variables, in relation tothe control. Doses between 4 and 6 mL of Stimulate® kg-1 of seeds promoted better balance between theroot and shoot, which can improve the establishment of the seedlings in the field

Twenty years of post-fire plant succession in a "cerrado", São Carlos, SP, Brazil

A sucessão secundária em áreas degradadas é pouco estudada, principalmente em relação ao acompanhamento dos processos evolutivos por longo período. O objetivo deste trabalho foi de verificar as mudanças qualitativas e quantitativas da vegetação durante o processo de regeneração após fogo em um cerrado com fisionomia de cerradão. A área estudada pertence a uma reserva institucional da CPPSE EMBRAPA, São Carlos, SP, Brasil. No ano de 1981 ocorreu um incêndio de proporções elevadas eliminando todo o folhedo e o dossel. O acompanhamento foi realizado em três parcelas fixas de 2 x 20 m ao longo de vinte anos. Os resultados demonstraram um rápido estabelecimento de indivíduos sucessivamente com plantas herbáceas, arbustivas, lianas e arbóreas, uma grande riqueza em espécies e, depois de determinado tempo, uma regressão em densidade na mesma ordem de estabelecimento. O banco de sementes do solo e o rebrotamento subterrâneo tiveram papel importante na recuperação da vegetação. No processo sucessional ocorreram três fases sucessivas: estabelecimento de plantas; competição intra-específica devido ao reajuste no número de indivíduos por espécies e competição interespecífica com a eliminação de algumas espécies das parcelas. As populações analisadas apresentaram padrões semelhantes de comportamento e a maior ou menor densidade ao longo do tempo refletiu o comportamento ecológico das espécies.

Natural recovery of steppe vegetation on vehicle tracks in central Mongolia.

Steppe desertification due to vehicle travel is a severe environmental issue in Mongolia. We studied natural vegetation recovery on abandoned vehicle tracks in the central Mongolia steppe through vegetation surveys and stable isotopic techniques. The following issues were addressed: (i) invasion of pioneering plant species, (ii) alteration of soil surface features, and (iii) contribution of revegetated plants to soil organic matter (SOM). The pioneering plant species that firstly invaded the abandoned tracks are those that could germinate, root and survive in the compacted track surface. Salsola collina is one of these candidate plants. Due to revegetation, soil surface hardness was reduced. With the improvement of surface microenvironmental conditions, other plants began to colonize and establish; con-comitantly species richness and species diversity increased. Carbon isotope ratios of SOM at the top surface layer indicated that C4 -derived carbon contributed more to SOM in the early phase of recovery and decreased with further recovery.