Resumo em Inglês:

A protein with a molecular mass of 22kDa was purified from the cellulosic parenchyma of cassava roots. The amino acid composition of the protein was determined and antibodies generated against the purified protein were used to show that the concentration of the protein remains unchanged during root "tuber" formation. By using a tissue printing technique, as well as western blot, it was shown that the cellulosic parenchyma was the only root tissue in which the protein was deposited.

Resumo em Inglês:

The germination of achenes of Bidens pilosa L. was analyzed during the life span of the mother plant. Decrease in the range of achene size was monitored until the senescence of the mother plant when the shortest achenes were harvested. The analysis of the germination percentage confirmed the presence of two distinct classes, formerly defined as short and long ones. Because length can not be used for the separation of those classes, the morphological characteristics of the tegument, specially of the ornament must be used for separation of the achenes with verrucose tegument (formerly named as short achenes) and achenes without ornament of the tegument (formerly named as long achenes). The achenes with verrucose tegument presented dormancy and light sensitivity, and the achenes without ornament of the tegument presented no dormancy and no light sensitivity for the germination process.

Resumo em Inglês:

Determination of α- and β-amylase activity in the extracts of cotyledons of Phaseolus vulgaris L. cv. cariocawas done using selective inactivation of α-amylase by lowering the pH of the incubation medium or by the use of EDTA as inhibitor or selective inactivation of β-amylase by the use of HgCl2 or by heating to 70ºC in the presence of CaCl2; and still by using the reagent starch azure for specific determination of α-amylase. Results indicated that the methods used were inappropriate in this case, being indicated the determination of total amylase activity.

Resumo em Inglês:

The present study aimed to evaluate the seasonal variation of microphytobenthic biomass and its primary production in the intertidal zone in Santos Estuary (São Paulo, Brazil). This estuary is on the tropical region and it is regarded as a polluted area. The samples were collected at 3 sites, and environmental parameters, nutrients and heavy metals were analyzed. The primary production was evaluated according to GRφNTVED (1960) method whereas chlorophyll a and phaeopigment a were estimated by TETT et al. (1975) method. Total nitrogen K ranged from 20.0 to 115.0 µg·g-1 while total phosphate ranged from 26.0 to 223.0 µg·g-1. No significant seasonal variation of benthic primary production or chlorophyll a and phaeopigment a were observed. Significant positive correlation was found for microbenthic primary production and chlorophyll a. Primary production showed lower correlations whit nitrate, total nitrogen K, total phosphate and organic matter in the sediment. The values of phaeopigment a were higher than chlorophyll a. The means for chlorophyll a were 10.4 µg·m-2 , 14.9 µg·m-2, 28.6 µg·m-2, 39.7 µg·m-2 and 26.7 µg·m-2. The mean values for primary production were 40.7 mgC·m-2.h-1 (summer); 51.3 mgC·m-2·h-1 (autumn); 84.3 mgC·m-2·h-1 (winter); 140.0 mgC·m-2·h-1 (spring) and 60.8 mgC·m-2·h-1 (summer).

Resumo em Inglês:

Cytological and cytochemical studies were carried out to investigate the surface characteristics of oocytes of four teleost species from the São Francisco river. The fishes were submitted to hypophysation at the Três Marias Hybrobiology and Fishculture Station, Minas Gerais, Brazil, in January 1996. Postspawning, oocytes of the curimatãs Prochilodus affinis, Prochilodus marggravii and dourado Salminus brasiliensis were surrounded by a thick, three-layered zona pellucida with radial striae. The surface of spawned oocytes of the surubim, Pseudoplatystoma coruscans, was comprised of mucous coat located externally to a thin, two-layered and striated zona pellucida. Oocyte activation during fertilization, lead to cortical reaction, formation of a perivitelline space, reduction of the thickness of the zona pellucida and increase in the oocyte diameter in the four species. Following fertilization, many spermatozoa were embedded in the mucous coat of the surubim oocytes. During embryogenesis, this later coating became thicker, diffuse and less viscous while the zona pellucida (chorion) was thinner in all studied species. Cytochemical analyses indicated species-specific differences in the oocyte surface after spawning. It was suggested that the mucous coat of surubim oocytes play a functional role during fertilization. The knowledge of the morphology of the oocyte surface of teleost is important for our understanding of the interactions between their eggs and surrounding environment and may also contribute significantly to phylogenetic studies.

Resumo em Inglês:

Larval development of Hoplias cf. lacerdae was studied under laboratory conditions. After hatching, ontogenetic changes were recorded on food-deprived larvae in 12-hour intervals. Mouth opening occurred after 2.5 days and notochord terminated flexure in 6.5 days. Notochord length increased at a constant rate until complete yolk absorption (13,5 days). Larval dry weight and body height diminished gradually up to 21 days after hatching, when all starved larvae died. Every 12 hours after yolk absorption, groups of larvae (n=15), were separeted, and fed with Artemia nauplii for 10 days. The point-of-no-return (when 50% of larvae were unable to feed or to assimilate ingested food after delayed feeding), was not apparent in this species.

Resumo em Inglês:

This work investigated the frog gastric mucosa response to hydrogen peroxide and ethanol induced injury. Acid and mucus secretion were estimated "in vitro" in control animals with intragastric absolute ethanol (1ml/30min. or 2ml/60min.) and hydrogen peroxide. The gastric mucosa morphological conditions were assessed "in vivo", concerning lesion area, pH and mucus. Ethanol (1ml/30min.) was observed to cause hyperemia, cell damage, rupture, edema, erosions, necrosis in gastric mucosa and significant increase in acid secretion. Absolute ethanol (2ml/60min.) caused a decrease in acid secretion due to alcalinization and an increase of mucus and pH. Intragastric hydrogem peroxide provoked gastric unwrinkling and hyperemia, acid secretions were not increased, mucus fragmented and the pH was decreased. The results indicate an increase of mucus and acid in response to ethanol and unwrinkling and hyperemia to hydrogen peroxide.

Resumo em Inglês:

The relationship between the physical environment and the biological diversification of fish communities was studied and the use of fluvial morphology as an indicative of priority areas for conservation was examined. As a case study the upper course of rio Macacu, State of Rio de Janeiro, Brazil was selected. Biotic data were obtained during 4 year of samples, conduced in 13 sample units. Each environment explored were characterized for its area, order, extension, slope and number of tributaries. Two new indices (environmental diversity and environmental turnover ratio) were proposed. To asses the correlation between the physical and biotic matrixes the data were compared using the Mantel test. A strong correlation between the physical variables and biodiversity were observed. An index to measure the ecological relevance of fluvial ecosystems based on the physical attributes was presented.

Resumo em Inglês:

With the objective to investigate the in vitro behavior of salix (Salix humboldtiana Willdenow), leaf and nodal segments were inoculated in WPM medium supplemented with NAA and IBA. In leaf explants, the presence of these growth regulators, isolated or in combination, induced the formation of adventicious roots. Root hairs were only observed when NAA was present. In nodal explants, while the combination of 2,68 µM ANA + 2,46 µM IBA induced bud growth, the other treatments (4,92 µM IBA; 2,68µM ANA + 4,92 µM IBA; 5,37 µM ANA + 4,92 µM IBA; 5,37µM ANA) induced the formation of adventicious roots.

Resumo em Inglês:

The potential of fluorescent Pseudomonas spp. to control Alternaria leaf spot on castorbean, caused by Alternaria ricini, was studied under greenhouse conditions. Two periods for antagonist applications were tested: 48h before and simultaneously to the pathogen inoculation. Among the antagonists tested JA4 and BJ22 were the most effectives showing disease severity reduction of 20.9% and 17.8% respectively, when applied simultaneously. The effect of Pseudomonas spp. on the micelial growth and sporulation was also studied throughout three different methods (funel, streak and celophane). Inhibition of micelial growth and sporulation was observed. There was no correlation between in vitro and in vivo data. Antibiosis was showed as a mode of action for Pseudomonas spp. in relation to Alternaria ricini. Ultrastructural studies confirmed the inhibition of spore germination by the bacteria.

Resumo em Inglês:

Forty-four Bacillus spp. strains obtained from sugar cane derivates and residues, six of them isolated in this work, were tested using Tween 80 as substrate (agar-Tween 80 medium), in order to determine their esterase activity through the enzymatic index averages. After statistic analysis, B. cereus (C124) strain, which presented better results, was submitted to genetic improvement by treatment with ultraviolet light (UV). The survival curve pointed out 28" as the time necessary to obtain 30% of survivors. Fifty survivors and the wild strain C124 were compared in relation to their esterase activity as mentioned previously. The wild strain and the mutant C124UV35, which showed enzymatic index average higher than C124, were characterized in polyacrilamide gel electrophoresis (PAGE). Eletrophoretic patterns for total proteins of wild and mutant strain showed different profiles according to number, position and intensity of bands. For esterase, the bands varied only in intensity.

Resumo em Inglês:

Toxicity and uptake of heavy metals of sewage sludge by beans (Phaseolus vulgaris L.) were evaluated in green house experiments. Treatments consisted of 1,0 ; 2,0 and 5,0% (m/m) of dry sewage sludge, collected from Londrina (Bom Retiro and ETE-Sul) and Curitiba (ETE-Belém and RALF). Bean ( variety IAPAR 57) was sown three times at 0, 120 and 240 days after the treatments have been applied. Contents of Cd, Cr, Co, Cu, Ni, and Pb in bean tissues cultivated with 5,0% (m/m) of all sewage sludge were similar to the control and Ba contents were reduced by increasing the quantity of sewage sludge in the soil. The Zn content in tissue bean incresed from 86 mg kg-1 of control to 462 mg kg-1 by applying 5% (m/m) of sewage sludge in soil, but plant beans did not show toxicity symptons. The addition of 5% (m/m) of sewage sludge increased Mn content in plants, from 193 mg kg-1 of control to 1.960 mg kg-1, showing toxity in bean leaves when the contents were more than 500 mg kg-1. The addition of sewage sludges in soils increased only available Zn carbonate and Cu organic species.

Resumo em Inglês:

The objective of this work was to evaluate the efficiency of delinting time of cottonseeds through the electrical conductivity and the quantity of neutral sugars and uronic acids leaked from the seeds during imbibition in water, in function of the fractioning in water and the artificial ageing. The seeds were delinted with commercial sulphuric acid for 1.5 and 4.5 minutes, separeted according to the sedimentation fractions in water and submitted to artificial ageing for 0, 72 and 96 hours. Electrical conductivity, contents of neutral sugars and uronic acids were determinated from the exudate resulting from the seeds imbibition in relation different treatments. The results showed that the delinting time for 1.5 minutes provided higher values of electrical conductivity, higher contents of neutral sugars and lower contents of uronic acids in relation with delinted seeds.

Resumo em Inglês:

Eight inoculation methods were studied to evaluate the pathogenicity among six isolates of Colletotrichum gloeosporioides, agent of anthracnose on passion fruits (Passiflora edulis). The isolates were selected by micelial growth and sporulation. The inoculations were made through suspension (1x10(6) conidia/ml) and micelial-agar discs (4mm in diameter). After 6 days of inoculation, the diameter of necrotic area was measure on the fruit epiderm. The most efficient inoculation method was the micelial-agar disc on the fruit wounded epiderm. All isolates caused necrosis by this method, but it showed low efficiency using intact epiderm, where only one isolate was active. One isolate from stem showed greater pathogenicity than the others, and the necrosis in the area was ten times larger than the less pathogenic isolates. The results showed that more than two inoculation methods must be used for the isolate evaluation.

Resumo em Inglês:

The aim of this work was to evaluate changes in technological properties of newly milled flours of BR-23, BR-35 and Anahuac varieties (Brazilian grown wheat) during storage for 180 days. Quality of samples was analysed for their rheological properties, acidity, falling number, glutomatic test and baking test, after periods of 0, 7, 15, 30, 60, 90, 120, 150 and 180 days. Most evident changes were the increase in flour acitidy and dough elasticity. The other characteristics did not show expressive changes. The flour of Anahuac variety was less influenced by the storage than the other ones. The results showed an increment in the flour quality, during 60-90 days of storage, althoug the baking test did not show expressive changes during all the period of storage.