Mites (Arachnida, Acari) on Citrus sinensis L. Osbeck orange trees in the state of Amazonas, Northern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Anti-inflammatory and analgesic activities of the crude extracts from stem bark of Bauhinia guianensis

Methylene chloride, ethyl acetate and methanolic extracts front the stem bark of Bauhinia guianensis (Leguminosae, Caesalpinoideae) were obtained. These extracts were evaluated for antiinflammatory activity which was conducted using carrageenin, dextran and histamine-induced paw edema in rats. The extracts of B. guianensis were also assessed for analgesic activity which was conducted using the writhing test in mouse. The different animal groups were treated with these extracts (100 mg/kg i.p. and p.o, IC50) 30 min prior to the application of stimuli. The methanolic extract demonstrated significant inhibition in the carrageenin-induced edema model. In the dextran-induced edema model, all three extracts inhibited the inflammatory process significantly with the methanolic extract being the most active. The ethyl acetate extract was the only one shown to be effective in the histamine-induced edema model. Finally all extracts inhibited effectively the algogenic process in the writhing test induced by acetic acid.

Attraction of ambrosia beetles (Coleoptera : Scolytidae) to different tropical pine species in Brazil

Ambrosia beetles are the predominant Scolytidae in Brazil. Little is known about the attractiveness of exotic conifer tree volatiles to native scolytids. Objectives were to compare the attractiveness of logs with and without bark of Pinus oocarpa Schiede, P. caribaea variety bahamensis Barrett & Golfari, P, car. variety caribaea Barrett & Golfari and P. car. variety hondurensis Barrett & Golfari over time to native scolytids in different pine stands, to compare the relative attractiveness of logs relative to ethanol traps, to determine how long it takes for logs to become attractive to ambrosia beetles and when attraction peaks occur, and to determine if volatiles released by live standing trees would mask volatiles released by logs of the same species. In young stands, Hypothenemus was the predominant insect genus, whereas in older stands Xyleborus predominated. Debarked logs trapped more beetles than logs with bark. Pine log species attractiveness was not influenced by volatiles present in the stand. Beetles were divided into the following 3 groups, based on response to log volatiles and ethanol: (1) species attracted to ethanol and not responding to pine terpenes Ambrosiodmus hagedorni (Iglesia), A. retusus (Eichhoff), X. spinulosus Blandford, Corthylus schaufussi Schiede, Cryptocarenus heveae (Hagedorn), H. obscurus (F.), (2) species attracted to ethanol but responding to pine terpenes Xyleborinus gracilis (Eichhoff), X. affinis Eichhoff, H. eruditus Westwood, Premnobius cavipennis Eichhoff, and (3) species more attracted to pine terpenes and less responsive to ethanol, A. obliquus (Le Conte), X. ferrugineus F,, X. catulus Blandford. Pinus car. ;variety bahamensis was the least attractive pine, P. oocarpa the most attractive. The attraction peak varied according to the season; logs were not attractive to beetles 10 wk after cutting.

Spatial patterns or trees in the Picinguara coastal sandy forest (state of Sao-Paulo, Brazil)

The species of the sandy plains forests (forests of the ''restingas'') have not yet had their spatial patterns studied as aids to the understanding of the diversity found in the different physiognomies along the Brazilian coast. In this paper a 10 x 10 m quadrat framework laid in a hectare of a tree dominant forest in the sandy plains of the Picinguaba area of the Serra do Mar State Park (municipality of Ubatuba, state of São Paulo, Brazil) was used to assess the spatial pattern of distribution for the ten most important species : Pera glabrata, Euterpe edulis, Eugenia brasiliensis, Alchornea triplinervea, Guatteria australis, Myrcia racemosa, Jacaranda semiserrata, Guarea macrophylla, Euplassa cantareirae and Nectandra oppositifolia. The spatial patterns were inferred through the calculations of their T-Square Index (C) and Dispersal Distance Index (I). P. glabrata shows a random pattern, E. edulis aggregate, E. brasiliensis, A. triplinervia, G. australis, E. cantareirae and N. oppositifolia with a tendency between aggregate and uniform and, M. racemosa, J. semiserrata and G. macrophylla between aggregate and random. Although the indexes are dependent of the sample size and of the technique adjustments, the relationship of the pattern with the environmental factors is shown by clustering methods. The results give confirmation of how the spatial patterns bring associations between populations and shape of the vegetation physiognomy.

Preliminary studies of Mammea americana L. (Guttiferae) bark/latex extract point to an effective antiulcer effect on gastric ulcer models in mice

Plant extracts are some of the most attractive sources of new drugs and have shown promising results for the treatment of gastric ulcers. Several folk medicinal plants and herbs have been used to treat gastrointestinal disorders, including gastric ulcers. Mammea americana L. (Guttiferae) fruit is very common in the diet of the population of northern South America. Our research interest in this plant arose because of its potential medicinal value as a tonic and against stomachache, as used in folk medicine. In this paper we evaluated three different extracts (ethanolic/EtOH, methanolic/MeOH and dichloromethane/DCM) obtained from M. americana L., for their ability to protect the gastric mucosa against injuries caused by necrotizing agents (0.3 M HCI/60% EtOH), hypothermic restraint stress, nonsteroidal anti-inflammatory drugs (NSAID, indomethacin) and pylorus ligation. In the HCI/EtOH-induced gastriculcer model, EtOH and DCM extracts demonstrated significant inhibition of the ulcerative lesion index by 54% (12.0 +/- 2.6 mm) and 86% (3.7 +/- 1.8 mm), respectively, in relation to the control value (26.0 +/- 1.4 mm) (p < 0.000 1). In the NSAID/cholinomimetic-induced lesion model, both EtOH and DCM extracts showed antiulcerogenic effects with significant reduction in the damage to these gastric lesions of 36% (8.3 +/- 2.0 mm) and 42% (7.5 +/- 1.4 mm), respectively, as compared to the control group (13.0 +/- 0.9 mm) (p < 0.0001). In the gastric ulcer induced by hypothermic-restraint stress, both extracts also showed significant activity, and inhibited the gastric lesion index by 58% and 75%, respectively. The EtOH and DCM extracts also changed gastric juice parameters as well as those of cimetidine, decreased gastric acid secretion significantly (p < 0.0001), increased pH values and promoted reduced acid output (p < 0.0001). In all gastric-ulcer-induced models, MeOH extract did not show any significant antiulcerogenic activity, nor did it change gastric-juice parameters (p > 0.05). The results suggest that EtOH and DCM extracts obtained from M. americana possess excellent antisecretory and/or gastrotective effect in all gastric ulcer models. These results suggest that the antiulcerogenic compound(s) present in M. americana may be clustered in the apolar fraction, which will be investigated by our group for the probable mechanisms of action. (c) 2004 Elsevier GmbH. All rights reserved.

Boron translocation in coffee trees

Boron deficiency in coffee trees ( Coffea arabica) is widespread, however, responses to B fertilizer have been erratic, depending on the year, method, and time of application. A better understanding of B uptake, distribution, and remobilization within the plant is important in developing a rational fertilization program. Field and greenhouse experiments were conducted to study B distribution and remobilization in coffee trees. Boron was provided either in the nutrient solution or sprayed on the leaves of trees grown under adequate or transient B deficiency. There was clear evidence for B translocation via symplast ( remobilization) to coffee grains, even in well-nourished plants. When 10 B was present in the nutrient solution during most part of fruit filling, from 33 to 40% of the B found in coffee fruits was absorbed during this period, depending on the timing and duration of the B deficiency treatment. In the field, when B was sprayed once on the leaves, around 4% of the fruit B was derived from the foliar fertilizer. Boron remobilization within coffee trees is limited in well nourished plants, but it can be significant during periods of temporary B deficiency in plants otherwise well nourished with B. The implications of these findings for B fertilization practice, are discussed.

Breeding systems of shrubs and trees of a Brazilian savanna

The reproductive biology of shrubs and trees of a preserved savanna (''cerrado'') area in the municipality of Corumbatai São Paulo State, Brazil was studied. The floral sexuality of 135 species were characterized, with 85.2 % hermaphroditic, 9.4 % dioecious, 4.5 % monoecious, and one determine the breeding systems. Nine apomictic species were found, all belonging Melastomataceae. Among the twelve sexual reproducing species, seven (58.3 %) proved to be self-compatible, and five (41.7 %) self-incompatible. Anemophily was found in five species, although pollinations systems were not investigated in other species.

Natural trans-crotonin: the antiulcerogenic effect of another diterpene isolated from the bark of Croton cajucara Benth.

The nor-clerodane diterpene trans-crotonin isolated from the bark of Croton cajucara BENTH. was investigated for its ability to prevent the formation of gastric-mucosa ulceration in different experimental models in mice. The results obtained from crotonin were compared with those obtained with another diterpene, DHC (trans-dehydrocrotonin) in the same models. When previously administered (p.o.) at the dose of 100 mg/kg, crotonin, as well as DHC, significantly reduced (p<0.05) gastric injury induced by stress (72, 67%), indomethacin/bethanechol (78, 29%) and pylorus ligature (35, 30%). In the HCl/ethanol-induced gastric ulcer model, at oral doses of 100 and 250 mg/kg, crotonin significantly prevented (p<0.05) the formation of gastric lesions by 51 and 56%, respectively, when compared to the control group. Gastric injury was also of significantly less magnitude in the DHC treatment group (p<0.05). In the pylorus-ligature model, crotonin (p.o.), like cimetidine, increased the volume of gastric juice when compared to the control group (p<0.05). No significant modifications where found in gastric parameters such as pH or total acid content after oral crotonin treatment. However, systemic alterations were observed when crotonin (100 mg/kg) was previously administered intraduodenally to mice. We observed significant changes (p<0.001) in gastric-juice parameters such as an increase in volume and a decrease in gastric acidity. Those pre-treated with crotonin as well as with DHC did not increase free mucus production (p>0.05). The results suggest that crotonin presents a significant anti-ulcer effect when assessed in these ulcer-induced models. As with DHC, the antiulcerogenic effects of crotonin are probably related to anti-secretory or/and gastroprotective properties of this substance. In light of results obtained with DHC and natural trans-crotonin in the present study, we concluded that the A-ring of both diterpenes is not directly involved in the antiulcerogenic activity.

Kinetics of zinc uptake and anatomy of roots and leaves of coffee trees as affected by zinc nutrition

Zinc (Zn) uptake kinetics and root and leaf anatomy were studied in coffee trees grown in nutrient solutions with or without Zn. Leaves and roots were sampled and cuts were made in the medium part of the leaves and in root tips and observed under an optical microscope. Plants grown without Zn showed an increase in root and in root stele diameter. There was also an increase in epidermis thickness and in the cross-sectional area of the cortex and stele due to Zn deficiency, but the diameter of xylem vessels was decreased. An increase in root cortex and stele diameter provided for an increased surface for nutrient uptake. Accordingly, C(min) was decreased from 13.8 to 3.4 mu mol L(-1) and V(max) increased from 0.50 to 2.1 mu mol cm(-2) h(-1) .

Sterolic and triterpenoidic constituents of stem bark of Drypetes gossweileri

Four compounds have been identified from the stem bark of Drypetes gossweileri by means of H-1- and C-13-NMR spectroscopy, stearic acid, methyl putranjate, and two new compounds: stigmasterol stearate and beta-sitosterol stearate.

Oviposition pattern and within-season spatial and temporal variation of pre-dispersal seed predation in a population of Mimosa bimucronata trees

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

Self-fertility and polyembryony in South American yellow trumpet trees (Handroanthus chrysotrichus and H. ochraceus, Bignoniaceae): a histological study of postpollination events

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

Anthocyanins and tannins in ozone-fumigated guava trees

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