Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
The foliar trichomes of Hypoestes aristata (Vahl) Sol. ex Roem. & Schult var aristata (Acanthaceae) a widespread medicinal plant species in tropical sub-Saharan Africa: with comments on its possible phylogenetic significance
Bhatt,A; Naidoo,Y; Nicholas,A;
Biological Research , 2010, DOI: 10.4067/S0716-97602010000400004
Abstract: the micromorphology of foliar trichomes of hypoestes aristata var. aristata was studied using stereo, light and scanning microscopy (sem). this genus belongs to the advanced angiosperm family acanthaceae, for which few micromorphological leaf studies exist. results revealed both glandular and non-glandular trichomes, the latter being more abundant on leaf veins, particularly on the abaxial surface of very young leaves. with leaf maturity, the density of non-glandular trichomes decreased. glandular trichomes were rare and of two types: long-stalked capitate and globose-like peltate trichomes. capitate trichomes were observed only on the abaxial leaf surface, while peltate trichomes were distributed on both adaxial and abaxial leaf surfaces.
In vitro Propagation of Adenium obesum (Forssk.) Roem. and Schult.  [cached]
Notulae Botanicae Horti Agrobotanici Cluj-Napoca , 2010,
Abstract: An in vitro protocol using shoot tip explants from seedling of Adenium obesum (Forssk.) Roem. and Schult. was developed. Explants were cultured on Murashige and Skoog (MS) medium supplemented with various combinations of NAA and BA. The most effective medium for shoot proliferation at a high frequency of 5.20±1.10 shoots per explant consisted of 22.2 μM BA. High rooting and survival were achieved using MS medium supplemented with 0.3% activated charcoal and without any growth regulators. Rooted plants were successfully acclimatized to greenhouse conditions. This study showed that A. obesum could be micropropagated by utilizing multiple shoots derived from seedling shoot tips. A flow cytometric analysis for DNA content revealed no differences among the micropropagated plants and the in vivo natural grown plants. The resulting 2C DNA value (8.35±0.039 pg) of this species was estimated for the first time.
Generalization versus Specialization in Pollination Systems: Visitors, Thieves, and Pollinators of Hypoestes aristata (Acanthaceae)  [PDF]
Eli?ka Pady?áková, Michael Barto?, Robert Tropek, ?těpán Jane?ek
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0059299
Abstract: Many recent studies have suggested that the majority of animal-pollinated plants have a higher diversity of pollinators than that expected according to their pollination syndrome. This broad generalization, often based on pollination web data, has been challenged by the fact that some floral visitors recorded in pollination webs are ineffective pollinators. To contribute to this debate, and to obtain a contrast between visitors and pollinators, we studied insect and bird visitors to virgin flowers of Hypoestes aristata in the Bamenda Highlands, Cameroon. We observed the flowers and their visitors for 2-h periods and measured the seed production as a metric of reproductive success. We determined the effects of individual visitors using 2 statistical models, single-visit data that were gathered for more frequent visitor species, and frequency data. This approach enabled us to determine the positive as well as neutral or negative impact of visitors on H. aristata’s reproductive success. We found that (i) this plant is not generalized but rather specialized; although we recorded 15 morphotaxa of visitors, only 3 large bee species seemed to be important pollinators; (ii) the carpenter bee Xylocopa cf. inconstans was both the most frequent and the most effective pollinator; (iii) the honey bee Apis mellifera acted as a nectar thief with apparent negative effects on the plant reproduction; and (iv) the close relationship between H. aristata and carpenter bees was in agreement with the large-bee pollination syndrome of this plant. Our results highlight the need for studies detecting the roles of individual visitors. We showed that such an approach is necessary to evaluate the pollination syndrome hypothesis and create relevant evolutionary and ecological hypotheses.
Bases débiles minoritarias de la raíz de Rauvolfia viridis Roem. et Schult.
Martínez Pérez,Jorge A; Bello Alarcón,Adonis; Montero Tápanes,Osmany; Fuente Fiallo,Víctor;
Revista Cubana de Farmacia , 1997,
Abstract: it was conducted a chemical study of the root of the species rauwolfia viridis roem. et schult. that grows in cuba aimed at depening in this topic. different alkaloids corresponding to the weak bases, such as ajmaline, a-yohimbin, quebrachidine, reserpine and yohimbin, were isolated, purified and characterized. the presence of reserpine is discarded.
Bases débiles minoritarias de la raíz de Rauvolfia viridis Roem. et Schult.  [cached]
Jorge A Martínez Pérez,Adonis Bello Alarcón,Osmany Montero Tápanes,Víctor Fuente Fiallo
Revista Cubana de Farmacia , 1997,
Abstract: Se realizó un estudio químico de la raíz de la especie Rauvolfia viridis Roem. et Schult. que crece en Cuba, con el objetivo de profundizar en este tema. Se aislaron, purificaron y caracterizaron diferentes alcaloides correspondientes a las bases débiles, entre los que se encuentran la ajmalidina, la a-yohimbina, la quebrachidina, la reserpinina y la yohimbina. Se descarta la presencia de reserpina. It was conducted a chemical study of the root of the species Rauwolfia viridis Roem. et Schult. that grows in Cuba aimed at depening in this topic. Different alkaloids corresponding to the weak bases, such as ajmaline, a-yohimbin, quebrachidine, reserpine and yohimbin, were isolated, purified and characterized. The presence of reserpine is discarded.
Allelic Variation, Alternative Splicing and Expression Analysis of Psy1 Gene in Hordeum chilense Roem. et Schult  [PDF]
Cristina Rodríguez-Suárez,Sergio G. Atienza,Fernando Pistón
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0019885
Abstract: The wild barley Hordeum chilense Roem. et Schult. is a valuable source of genes for increasing carotenoid content in wheat. Tritordeums, the amphiploids derived from durum or common wheat and H. chilense, systematically show higher values of yellow pigment colour and carotenoid content than durum wheat. Phytoene synthase 1 gene (Psy1) is considered a key step limiting the carotenoid biosynthesis, and the correlation of Psy1 transcripts accumulation and endosperm carotenoid content has been demonstrated in the main grass species.
Anticonvulsant evaluation of Rauvolfia ligustrina Willd. ex Roem. & Schult., Apocynaceae, in rodents
Quintans-Júnior, Lucindo J.;Siqueira, Jullyana S.;Melo, M?nica S.;Silva, Davi A.;Morais, Liana C. S. L.;Souza, Maria de Fátima V.;Almeida, Reinaldo N.;
Revista Brasileira de Farmacognosia , 2010, DOI: 10.1590/S0102-695X2010000100012
Abstract: the aim of this study was to evaluated the effects of the ethanol extract of rauvolfia ligustrina willd. ex roem. & schult., apocynaceae, roots (eer) in animal models of epilepsy. the eer increased the latency for convulsions significantly different from control (p<0,05) and in the ptz induced convulsions test on 62,5 mg/kg (i.p.) decreased mortality. this effect was blocked by flumazenil administration, suggesting an involvement of gabaergic system in the anticonvulsant activity of eer. the eer had a moderate effect only against pic- or str-induced convulsions at doses 125 and 250 mg/kg. but in the mes test it did not demonstrate effect on this animal model. therefore, the eer reduced the development of ptz-induced kindling in both experimental groups. it also significantly (p<0.05) decreased the latency for convulsions and reduced its percentage. our results suggest that eer owns anticonvulsant property.
Anticonvulsant properties of the total alkaloid fraction of Rauvolfia ligustrina Roem. et Schult. in male mice
Quintans-Júnior, Lucindo J.;Silva, Davi A.;Siqueira, Jullyana S.;Souza, Maria de Fátima V. de;Almeida, Reinaldo N.;Silva-Júnior, René G. C.;
Revista Brasileira de Farmacognosia , 2007, DOI: 10.1590/S0102-695X2007000200007
Abstract: rauvolfia ligustrina roem et. schult (apocynaceae), commonly known as "paratudo" and "arrebenta-boi" is a small tree found in brazilian northeastern. previous studies have demonstrated depressant and anticonvulsant properties of the ethanol extract of rauvolfia ligustrina. the aim of the present study was the determination of the lethal dose 50% (ld50) and the effects of total alkaloid fraction (taf) of the aerial parts of r. ligustrina in animal models of convulsion. it was found that the acute toxicity of taf was 127.8 (112.5-145.2) mg/kg (i.p.) in mice. taf (20 mg/kg, ip) significantly increased (p < 0.05) the latencies of clonic seizures induced by pentylenetetrazol (ptz) and picrotoxin (pic). however, taf did not protect the animals in maximal electroshock (mes) induced seizures. these results suggest that taf of r. ligustrina possesses anticonvulsant properties.
Effect of light intensity and growth substratum on plant development and production of secondary metabolites in Cordia curassavica (Jacq.) Roem. & Schult
Paulilo, Maria Terezinha Silveira;Lapa, Flávia Sim?o;Falkenberg, Miriam de Barcellos;
Revista árvore , 2010, DOI: 10.1590/S0100-67622010000300005
Abstract: cordia curassavica (jacq.) roem. & schult. (boraginaceae), also referred to as cordia verbenacea dc, has been traditionally used for medicinal purposes. this study was driven to verify the behavior of the species in similar conditions to its natural environment, such as high light intensity and sandbank soil, and in conditions of low light intensity and fertilized substratum (dystroferric red nitosoil plus earthworm humus). the growth of the plant, the income of leaf crude extracts and, in the alcoholic extract, the number of substances found in thin layer cromatography and the toxicity of the substratum was observed. the results indicated that the growth of the root biomass, stem and leaves in discharge or lower light intensity was similar, but smaller in sandbank soil than in fertilized soil. the relative income of extracts in ether of petroleum and alcohol was larger in high light intensity and fertilized substratum. the light intensity and the substratum type didn't affect the number of substances detected in the alcoholic extract or the toxicity of this extract. stains corresponding to the rosmarinic acid were only evidenced in some samples of the alcoholic extract, not allowing the verification of the effect of the treatments about its production.
Comparison of leaf morphoanatomy of Diodella radula (Willd. & Hoffmanns. Ex Roem. & Schult.) Delprete and Diodella teres (Walter) Small (Rubiaceae)
International Journal of Plant Research , 2012, DOI: 10.5923/j.plant.20120202.08
Abstract: Diodella radula (Willd. & Hoffmanns. ex Roem. & Schult.) Delprete e Diodella teres (Walter) Small (Rubiaceae) are weeds found in agricultural areas from Mato Grosso do Sul and it is difficult to identify them on vegetative phase, so the morphologic and anatomic studies are an important instrument for controling the species. This work intended to characterize the leaf morphoanatomy of Diodella radula and D. teres, aiming to promote taxonomic subsidies and determine the structures which may influence on the herbicides absorption. The morphoanatomic studies were carried out with fresh material and fixed. Cross and paradermic sections of leaf blade were obtained. The cutting edges were dyed as an usual methodology and submitted to histochemical tests. These species are distinguished plants because they can stay in the sun; Diodella teres is frequently found on the edge of the roads, on a drier soil while D. radula is mainly found on dirty fields, damp soil and at the river banks. D. radula and D. teres leaves present general characteristics quoted for Rubiaceae family, as for example, unilayered epidermis, paracytic stomata, dorsiventral mesophyll and collateral vascular bundles. The observed characteristics such as epidermic cells, papilla size, glandular trichomes and collenchyma arrangement are distinct for both species and therefore they may be used as characters to bound the two species. The low density of stomata and the cuticle thickness on the adaxial surface observed in D. radula and D. teres seems to be leaf barrier to block the herbicides penetration.
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.